Context:
A 26-year-old pregnant woman (gravida 2, para 1) presents on her 25th week of pregnancy. Currently, she has no complaints. Her previous pregnancy was unremarkable. No abnormalities were detected on the previous ultrasound (US) examination at week 13 of pregnancy. She had normal results on the triple test. She is human immunodeficiency virus (HIV), hepatitis B virus (HBV), and hepatitis C virus (HCV)-negative. Her blood type is III(B) Rh+, and her partner has blood type I(0) Rh-. She and her husband are both of Sardinian descent, do not consume alcohol, and do not smoke. Her cousin had a child who died soon after the birth, but she doesn't know the reason. She does not report a history of any genetic conditions in her family, although notes that her grandfather “was always yellowish-pale, fatigued easily, and had problems with his gallbladder”. Below are her and her partner’s complete blood count and electrophoresis results.
Complete blood count
  Patient Her husband
Erythrocytes 3.3 million/mm3 4.2 million/mm3
Hb 11.9 g/dL 13.3 g/dL
MCV 71 fL 77 fL
Reticulocyte count 0.005 0.008
Leukocyte count 7,500/mm3 6,300/mm3
Platelet count 190,000/mm3 256,000/mm3
Electrophoresis
HbA1 95% 98%
HbA2 3% 2%
HbS 0% 0%
HbH 2% 0%
The patient undergoes ultrasound examination which reveals ascites, liver enlargement, and pleural effusion in the fetus. Further evaluation with Doppler ultrasound shows elevated peak systolic velocity of the fetal middle cerebral artery. Which of the following procedures can be performed for both diagnostic and therapeutic purposes in this case?

Question: Which of the following procedures can be performed for both diagnostic and therapeutic purposes in this case?

Answer: Cordocentesis


Context: DNA replication is a highly complex process where replication occurs on both strands of DNA. On the leading strand of DNA, replication occurs uninteruppted, but on the lagging strand, replication is interrupted and occurs in fragments called Okazaki fragments. These fragments need to be joined, which of the following enzymes is involved in the penultimate step before ligation can occur?

Question: These fragments need to be joined, which of the following enzymes is involved in the penultimate step before ligation can occur?

Answer: DNA polymerase I


Context: A 3-day-old boy develops several episodes of complete body shaking while at the hospital. The episodes last for about 10–20 seconds. He has not had fever or trauma. He was born at 40 weeks' gestation and has been healthy. The mother did not follow-up with her gynecologist during her pregnancy on a regular basis. There is no family history of serious illness. The patient appears irritable. Vital signs are within normal limits. Physical examination shows reddening of the face. Peripheral venous studies show a hematocrit of 68%. Neuroimaging of the head shows several cerebral infarctions. Which of the following is the most likely cause of this patient's findings?

Question: Which of the following is the most likely cause of this patient's findings?

Answer: Maternal diabetes


Context: A 3-month-old boy is brought to the physician by his mother because of poor weight gain. She also reports a dusky blue discoloration to his skin during feedings and when crying. On examination, there is a harsh, systolic murmur heard over the left upper sternal border. An x-ray of the chest is shown below. Which of the following is the most likely cause of his symptoms?

Question: Which of the following is the most likely cause of his symptoms?

Answer: Right ventricular outflow obstruction


Context: A 35-year-old male presents to his primary care physician with pain along the bottom of his foot. The patient is a long-time runner but states that the pain has been getting worse recently. He states that when running and at rest he has a burning and aching pain along the bottom of his foot that sometimes turns to numbness. Taking time off from training does not improve his symptoms. The patient has a past medical history of surgical repair of his Achilles tendon, ACL, and medial meniscus. He is currently not taking any medications. The patient lives with his wife and they both practice a vegan lifestyle. On physical exam the patient states that he is currently not experiencing any pain in his foot but rather is experiencing numbness/tingling along the plantar surface of his foot. Strength is 5/5 and reflexes are 2+ in the lower extremities. Which of the following is the most likely diagnosis?

Question: Which of the following is the most likely diagnosis?

Answer: Tarsal tunnel syndrome


Context: A previously healthy 64-year-old woman comes to the physician because of a dry cough and progressively worsening shortness of breath for the past 2 months. She has not had fever, chills, or night sweats. She has smoked one pack of cigarettes daily for the past 45 years. She appears thin. Examination of the lung shows a prolonged expiratory phase and end-expiratory wheezing. Spirometry shows decreased FEV1:FVC ratio (< 70% predicted), decreased FEV1, and a total lung capacity of 125% of predicted. The diffusion capacity of the lung (DLCO) is decreased. Which of the following is the most likely diagnosis?

Question: Which of the following is the most likely diagnosis?

Answer: Chronic obstructive pulmonary disease


Context: A 33-year-old man presents to the clinic complaining of multiple painful joints for the past 2 weeks. The patient notes no history of trauma or any joint disorders. The patient states that he is generally healthy except for a recent emergency room visit for severe bloody diarrhea, which has resolved. On further questioning, the patient admits to some discomfort with urination but notes no recent sexual activity. On examination, the patient is not in acute distress, with no joint deformity, evidence of trauma, swelling, or erythema. He has a decreased range of motion of his right knee secondary to pain. Vital signs are as follows: heart rate 75/min, blood pressure 120/78 mm Hg, respiratory rate 16/min, and temperature 37.3°C (99.0°F). What is the next step in the treatment of this patient?

Question: What is the next step in the treatment of this patient?

Answer: Nonsteroidal anti-inflammatory drugs (NSAIDs) or immunosuppressants


Context: A 28-year-old woman presents to the emergency department with lateral knee pain that started this morning. The patient is a college student who is currently on the basketball team. She states her pain started after she twisted her knee. Her current medications include albuterol and ibuprofen. The patient's vitals are within normal limits and physical exam is notable for tenderness to palpation over the lateral right knee. When the patient lays on her left side and her right hip is extended and abducted it does not lower to the table in a smooth fashion and adduction causes discomfort. The rest of her exam is within normal limits. Which of the following is the most likely diagnosis?

Question: Which of the following is the most likely diagnosis?

Answer: Iliotibial band syndrome


Context: A 56-year-old man comes to the physician for a follow-up examination. One month ago, he was diagnosed with a focal seizure and treatment with a drug that blocks voltage-gated sodium channels was begun. Today, he reports that he has not had any abnormal body movements, but he has noticed occasional double vision. His serum sodium is 132 mEq/L, alanine aminotransferase is 49 U/L, and aspartate aminotransferase is 46 U/L. This patient has most likely been taking which of the following drugs?

Question: This patient has most likely been taking which of the following drugs?

Answer: Carbamazepine


Context: A 22-year-old woman comes to the physician to discuss the prescription of an oral contraceptive. She has no history of major medical illness and takes no medications. She does not smoke cigarettes. She is sexually active with her boyfriend and has been using condoms for contraception. Physical examination shows no abnormalities. She is prescribed combined levonorgestrel and ethinylestradiol tablets. Which of the following is the most important mechanism of action of this drug in the prevention of pregnancy?

Question: Which of the following is the most important mechanism of action of this drug in the prevention of pregnancy?

Answer: Inhibition of rise in luteinizing hormone


Context: A 13-year-old boy is brought to the emergency department by his mother because of vomiting and severe testicular pain for 3 hours. The boy has had 4–5 episodes of vomiting during this period. He has never had a similar episode in the past and takes no medications. His father died of testicular cancer at the age of 50. His immunizations are up-to-date. He appears anxious and uncomfortable. His temperature is 37°C (98.6°F), pulse is 90/min, respirations are 14/min, and blood pressure is 100/60 mm Hg. Cardiopulmonary examination shows no abnormalities The abdomen is soft and nondistended. The left scrotum is firm, erythematous, and swollen. There is severe tenderness on palpation of the scrotum that persists on elevation of the testes. Stroking the inner side of the left thigh fails to elicit elevation of the scrotum. Which of the following is the most appropriate next step in management?

Question: Which of the following is the most appropriate next step in management?

Answer: Surgical exploration of the scrotum


Context: A 32-year-old woman comes to the physician for a screening health examination that is required for scuba diving certification. The physician asks her to perform a breathing technique: following deep inspiration, she is instructed to forcefully exhale against a closed airway and contract her abdominal muscles while different cardiovascular parameters are evaluated. Which of the following effects is most likely after 10 seconds in this position?

Question: Which of the following effects is most likely after 10 seconds in this position?

Answer: Decreased left ventricular stroke volume


Context: A 71-year-old man comes to the physician for a health maintenance examination. Aside from occasional lower back pain in the last couple of years, he feels well. He had a right-sided myocardial infarction 4 years ago. Currently, he has no shortness of breath and has no anginal symptoms. He has a 30 pack-year history of smoking but stopped smoking 10 years ago and does not drink alcohol. His pulse is 59/min, and his blood pressure is 135/75 mm Hg. Physical examination reveals 1+ lower extremity edema. Cardiac and pulmonary auscultation show no abnormalities. There is no lymphadenopathy. His laboratory studies show a hemoglobin of 13.2 g/dL and serum protein of 10.1 g/dL. ECG shows known Q wave abnormalities unchanged since the last ECG one year ago. A serum protein electrophoresis with immunofixation is shown. Which of the following is the most appropriate next step to establish the diagnosis?

Question: Which of the following is the most appropriate next step to establish the diagnosis?

Answer: Whole-body CT scan


Context: A 75-year-old man presents to his primary care provider with malaise and low-grade fever after he underwent a cystoscopy for recurrent cystitis and pyelonephritis two weeks ago. His past medical history is significant for coronary artery disease and asthma. His current medications include aspirin, metoprolol, atorvastatin, and albuterol inhaler. Temperature is 37.2°C (99.0°F), blood pressure is 110/70 mm Hg, pulse is 92/min and respirations are 14/min. On physical examination, there are painless areas of hemorrhage on his palms and soles. Cardiac auscultation reveals a new pansystolic murmur over the apex. An echocardiogram shows echogenic endocardial vegetation on a leaflet of the mitral valve. Which of the following pathogens is most likely responsible for his condition?

Question: Which of the following pathogens is most likely responsible for his condition?

Answer: Enterococcus


Context: A 15-month-old girl is brought to her primary care physician for a follow-up visit to receive the 4th dose of her DTaP vaccine. She is up-to-date on her vaccinations. She received her 1st dose of MMR, 1st dose of varicella, 3rd dose of HiB, 4th dose of PCV13, and 3rd dose of polio vaccine 3 months ago. Thirteen days after receiving these vaccinations, the child developed a fever up to 40.5°C (104.9°F) and had one generalized seizure that lasted for 2 minutes. She was taken to the emergency department. The girl was sent home after workup for the seizure was unremarkable and her temperature subsided with acetaminophen therapy. She has not had any other symptoms since then. She has no history of serious illness and takes no medications. Her mother is concerned about receiving further vaccinations because she is afraid of the girl having more seizures. Her vital signs are within normal limits. Examination shows no abnormalities. Which of the following is the most appropriate recommendation at this time?

Question: Which of the following is the most appropriate recommendation at this time?

Answer: Administration of the DTaP vaccine as scheduled


Context:
A 46-year-old man comes to the physician for a follow-up examination. He has type 2 diabetes mellitus and hypertension. Current medications include metformin and lisinopril. He reports that he has adhered to his diet and medication regimen. His hemoglobin A1c is 8.6%. Insulin glargine is added to his medication regimen. Which of the following sets of changes is most likely to occur in response to this new medication?
$$$ Glycolysis %%% Glycogenesis %%% Lipolysis %%% Gluconeogenesis $$$

Question: $$$ Glycolysis %%% Glycogenesis %%% Lipolysis %%% Gluconeogenesis $$$


Context: A 39-year-old woman with multiple sclerosis comes to the physician for a follow-up examination. Over the past 3 years, she has been hospitalized 7 times for acute exacerbations of her illness. She has not responded to therapy with several disease-modifying agents and has required at least two pulse corticosteroid therapies every year. She has seen several specialists and sought out experimental therapies. During this time period, her disease course has been rapidly progressive. She currently requires a wheelchair and is incontinent. Today, she says, “I'm not going to allow myself to hope because I'll only be disappointed, like I have been over and over again. What's the point? No one in this system knows how to help me. Sometimes I don't even take my pills any more because they don't help.” Which of the following is the most appropriate initial response to this patient?

Question: Sometimes I don't even take my pills any more because they don't help.” Which of the following is the most appropriate initial response to this patient?

Answer: """I'm very sorry to hear that you feel this way about your situation. With all that you've been through, I can see why you would be so frustrated."""


Context: A 60-year-old man comes to the emergency room for a persistent painful erection for the last 5 hours. He has a history of sickle cell trait, osteoarthritis, insomnia, social anxiety disorder, gout, type 2 diabetes mellitus, major depressive disorder, and hypertension. He drinks 1 can of beer daily, and smokes marijuana on the weekends. He takes propranolol, citalopram, trazodone, rasburicase, metformin, glyburide, lisinopril, and occasionally ibuprofen. He is alert and oriented but in acute distress. Temperature is 36.5°C(97.7°F), pulse is 105/min, and blood pressure is 145/95 mm Hg. Examination shows a rigid erection with no evidence of trauma, penile discharge, injection, or prosthesis. Which of the following is the most likely cause of his condition?

Question: Which of the following is the most likely cause of his condition?

Answer: Trazodone


Context: A 60-year-old man presents with severe chronic neck pain. 6 months ago, the patient was in a motor vehicle accident where he sustained a severe whiplash injury. Initial radiographs were negative for fractures, and he was treated with cyclobenzaprine and tramadol and discharged with outpatient follow-up. He says that despite being compliant with his medication, the pain is not going away. It keeps him up at night and prevents him from focusing at work or at home. He also feels that none of the other doctors can help him. Past medical history includes hypertension, hyperlipidemia, and gout for which he takes chlorthalidone, atorvastatin, and allopurinol. He has no family and lives alone. He has never attempted to take his life but thinks that it might be better than living in pain forever. He has a gun at home and plans to commit suicide in the near future. Which of the following is the single best initial treatment option for this patient’s condition?

Question: Which of the following is the single best initial treatment option for this patient’s condition?

Answer: Admission into the hospital


Context: A 7-year-old boy is brought to the emergency department because of photophobia and pruritus on the periocular area of the right eye for the last 2 days. He also had crusts over the eyelashes of the right eye that morning. The boy has a history of asthma and atopic dermatitis. His medications include inhaled steroids and salbutamol. Vital signs are within normal limits. Physical examination shows conjunctival injection and redness in the affected eye, as well as a watery discharge from it. There are multiple vesicles with an erythematous base located on the upper and lower eyelids. Visual acuity is within normal limits. Which of the following is the most likely cause?

Question: Which of the following is the most likely cause?

Answer: Herpes simplex virus


Context: A 70-year-old man presents for a routine checkup. He says that he recently completely lost hearing in both ears and has been having occasional flare-ups of osteoarthritis in his hands and hips. Past medical history is significant for hypertension diagnosed 25 years ago that is well controlled. Family history is significant for his brother, who recently died from prostate cancer. The patient's blood pressure is 126/84 mm Hg. Laboratory findings are significant for an alkaline phosphatase level that is more than 3 times the upper limit. Right upper quadrant ultrasound and non-contrast computed tomography of the abdomen and pelvis reveal no significant abnormalities. Which of the following is the most likely complication of this patient’s condition?

Question: Which of the following is the most likely complication of this patient’s condition?

Answer: Osteosarcoma


Context: A six year-old female presents for evaluation of dry skin, fatigue, sensitivity to cold and constipation. The patient’s mother recalls that the patient had surgery to remove a “benign mass” at the base of her tongue 3 months ago because of trouble swallowing. What was the likely cause of the surgically removed mass?

Question: What was the likely cause of the surgically removed mass?

Answer: Failed caudal migration of the thyroid gland


Context: During normal respiration in the lungs, oxygen is absorbed into the bloodstream and carbon dioxide is released. The oxygen is used in cells as the final electron acceptor during oxidative phosphorylation, and carbon dioxide is generated during each turn of the tricarboxylic citric acid cycle (TCA). Which of the following steps in the TCA cycle generates a molecule of carbon dioxide?

Question: Which of the following steps in the TCA cycle generates a molecule of carbon dioxide?

Answer: Isocitrate to alpha ketoglutarate


Context:
A 46-year-old man presents to the emergency room after an industrial accident at a plastic manufacturer with altered consciousness, headache, shortness of breath, and abdominal pain. The vital signs include: blood pressure 145/80 mm Hg, heart rate 111/min, respiratory rate 27/min, and temperature 37.0℃ (98.6℉). The blood oxygen saturation on room air is 97%. On physical examination, the patient has a GCS score of 13. The skin is cherry-red and covered with perspiration. Breath and heart sounds are decreased. There is widespread tenderness on abdominal palpation. Blood testing shows the following findings:
pH 7.29
Po2 66 mm Hg
Pco2 30 mm Hg
Na+ 144 mEq/L
K+ 5.1 mEq/L
Cl- 107 mEq/L
HCO3- 11 mEq/L
Base Excess -5 mEq/L
Lactate  22 mmol/L (198.2 mg/dL)
Inhibition of which enzyme caused this patient’s condition?

Question:
Blood testing shows the following findings:
pH 7.29
Po2 66 mm Hg
Pco2 30 mm Hg
Na+ 144 mEq/L
K+ 5.1 mEq/L
Cl- 107 mEq/L
HCO3- 11 mEq/L
Base Excess -5 mEq/L
Lactate  22 mmol/L (198.2 mg/dL)
Inhibition of which enzyme caused this patient’s condition?

Answer: Cytochrome C oxidase


Context:
A 57-year-old woman comes to the physician for a routine health maintenance examination. She has well-controlled type 2 diabetes mellitus, for which she takes metformin. She is 163 cm (5 ft 4 in) tall and weighs 84 kg (185 lb); BMI is 31.6 kg/m2. Her blood pressure is 140/92 mm Hg. Physical examination shows central obesity, with a waist circumference of 90 cm. Laboratory studies show:
Fasting glucose 94 mg/dl
Total cholesterol 200 mg/dL
High-density lipoprotein cholesterol 36 mg/dL
Triglycerides 170 mg/dL
Without treatment, this patient is at greatest risk for which of the following conditions?"

Question:
Laboratory studies show:
Fasting glucose 94 mg/dl
Total cholesterol 200 mg/dL
High-density lipoprotein cholesterol 36 mg/dL
Triglycerides 170 mg/dL
Without treatment, this patient is at greatest risk for which of the following conditions?"

Answer: Liver cirrhosis


Context: A 38-year-old woman presented to a clinic because of dementia, hemiparesis, ataxia, aphasia, and dysarthria that developed over the last 5 days. She had a 15-year history of intravenous drug abuse and was treated for fever, cough, and shortness of breath before the onset of neurological symptoms. Her MRI shows multiple white matter lesions, as seen in the picture. Over the course of 2 weeks, the patient's condition worsens. Despite aggressive treatment, she lapses into a coma and dies. At autopsy, histologic examination of her brain tissue reveals gigantic, deformed astrocytes and oligodendrocytes with abnormal nuclei. Which of the following is the most likely cause of this woman's neurological symptoms?

Question: Which of the following is the most likely cause of this woman's neurological symptoms?

Answer: A double-stranded circular DNA virus


Context: A 55-year-old man presents to the emergency department with shortness of breath and fatigue. His symptoms began insidiously and progressively worsened over the course of a month. He becomes short of breath when climbing the stairs or performing low-intensity exercises. He also needs to rest on multiple pillows in order to comfortably sleep. A few weeks ago he developed fever, malaise, and chest pain. Medical history is significant for hypertension, hypercholesterolemia, type II diabetes, and bariatric surgery performed 10 years ago. He is taking lisinopril, atorvastatin, and metformin. He drinks alcohol occasionally and does not smoke. He tried cocaine 3 days ago for the first time and has not used the illicit drug since. Physical exam is significant for bibasilar crackles, an S3 heart sound, and a laterally displaced cardiac apex. He has normal muscle tone throughout, 2+ reflexes, and an intact sensory exam. Which of the following is most likely the cause of this patient's symptoms

Question: Which of the following is most likely the cause of this patient's symptoms

Answer: Enterovirus


Context: A 71-year-old man with hypertension is taken to the emergency department after the sudden onset of stabbing abdominal pain that radiates to the back. He has smoked 1 pack of cigarettes daily for 20 years. His pulse is 120/min and thready, respirations are 18/min, and blood pressure is 82/54 mm Hg. Physical examination shows a periumbilical, pulsatile mass and abdominal bruit. There is epigastric tenderness. Which of the following is the most likely underlying mechanism of this patient's current condition?

Question: Which of the following is the most likely underlying mechanism of this patient's current condition?

Answer: Aortic wall stress


Context: A 75-year-old man comes to the physician because of a 3-month history of upper abdominal pain, nausea, and sensation of early satiety. He has also had a 9.4-kg (20.7-lb) weight loss over the past 4 months. He has osteoarthritis. He drinks two beers every night with dinner. His only medication is ibuprofen. Esophagogastroduodenoscopy shows an ulcerated mass in the lesser curvature of the stomach. A biopsy specimen obtained during endoscopy shows irregular-shaped tubules with intraluminal mucus and debris. Which of the following is the most likely predisposing factor for this patient's condition?

Question: Which of the following is the most likely predisposing factor for this patient's condition?

Answer: Dietary nitrates


Context: A 48-year-old male presents to his primary physician with the chief complaints of fever, abdominal pain, weight loss, muscle weakness, and numbness in his lower extremities. UA is normal. A biopsy of the sural nerve reveals transmural inflammation and fibrinoid necrosis of small and medium arteries. Chart review reveals a remote history of cigarette smoking as a teenager and Hepatitis B seropositivity. What is the most likely diagnosis?

Question: What is the most likely diagnosis?

Answer: Polyarteritis nodosa


Context: A 3-day-old girl is brought to the general pediatrics clinic by her mother. She was the product of an uncomplicated, full-term, standard vaginal delivery after an uncomplicated pregnancy in which the mother received regular prenatal care. This morning, after changing the child's diaper, the mother noticed that the newborn had a whitish, non-purulent vaginal discharge. The mother has no other complaints, and the infant is eating and voiding appropriately. Vital signs are stable. Physical exam reveals moderate mammary enlargement and confirms the vaginal discharge. The remainder of the exam is unremarkable. What is the next step in management?

Question: What is the next step in management?

Answer: No tests are needed


Context:
A pilot study is conducted to determine the therapeutic response of a new antidepressant drug in patients with persistent depressive disorder. Twelve participants are randomized into a control and a treatment group (n=6 patients in each). They are asked to subjectively rate the severity of their depression from 1 (low) to 10 (high) before and after taking a pill (control group = placebo; treatment group = antidepressant). The data from this study are shown in the following table:
Subject Control group Treatment group
  Depression ranking before intervention Depression ranking after intervention Depression ranking before intervention Depression ranking after intervention
1 7 5 6 4
2 8 6 8 4
3 7 6 9 2
4 5 5 7 5
5 6 6 10 3
6 9 7 6 4
Which of the following is the difference between the median of the depression scores before intervention in the treatment group and the control group?

Question:
The data from this study are shown in the following table:
Subject Control group Treatment group
  Depression ranking before intervention Depression ranking after intervention Depression ranking before intervention Depression ranking after intervention
1 7 5 6 4
2 8 6 8 4
3 7 6 9 2
4 5 5 7 5
5 6 6 10 3
6 9 7 6 4
Which of the following is the difference between the median of the depression scores before intervention in the treatment group and the control group?

Answer: 0.5


Context: A 6-year-old boy with a history of multiple fractures is brought to his pediatrician by his mother, because she is concerned her child cannot hear her. On physical exam, kyphoscoliosis, poor dentition, bowing of long bones, and conductive hearing loss is noted. On genetic analysis, the patient has a COL1A1 gene mutation. The defect found in this patient is most likely associated with impaired formation of which of the following?

Question: The defect found in this patient is most likely associated with impaired formation of which of the following?

Answer: Sclera


Context:
A 43-year-old man presents with the complaint of pain in the small joints of his left hand. The pain is intermittent and cramping in nature in his 2nd and 3rd metacarpophalangeal (MCP) joints. It has progressively worsened over the past few weeks. He also reports that he has felt thirsty more often and has urinated more frequently over the past few weeks. He denies any pain during micturition. His stools are pale in color. He also reports that his skin appears to be darker than usual even though he has not been outdoors much over the past few weeks. Physical exam is significant for tenderness in the 2nd and 3rd MCPs of both hands as well as tenderness in the right upper quadrant of his abdomen. Lab results show:
Aspartate aminotransferase (AST) 450 U/L
Alanine aminotransferase (ALT) 350 U/L
Serum ferritin 460 ng/mL
Deficiency of which of the following is the most likely cause of his symptoms?

Question:
Lab results show:
Aspartate aminotransferase (AST) 450 U/L
Alanine aminotransferase (ALT) 350 U/L
Serum ferritin 460 ng/mL
Deficiency of which of the following is the most likely cause of his symptoms?

Answer: Hepcidin


Context: A 26-year-old man is brought to the hospital by his wife who complains that her husband has been behaving oddly for the past few hours. The patient’s wife says that she has known him for only 4 months. The wife is unable to give any past medical history. The patient’s speech is difficult to follow, and he seems very distracted. After 15 minutes, he becomes agitated and starts to bang his head on a nearby pillar. He is admitted to the psychiatric ward and is given an emergency medication, after which he calms down. In the next 2 days, he continues to become agitated at times and required 2 more doses of the same drug. On the 4th day of admission, he appears very weak, confused, and does not respond to questions appropriately. His vital signs include: temperature 40.0°C (104.0°F), blood pressure 160/95 mm Hg, and pulse 114/min. On physical examination, he is profusely diaphoretic. He is unable to stand upright or even get up from his bed. Which of the following is the mechanism of action of the drug which most likely caused this patient’s current condition?

Question: Which of the following is the mechanism of action of the drug which most likely caused this patient’s current condition?

Answer: Dopamine receptor blocking


Context:
A 64-year-old man who has not seen a physician in over 20 years presents to your office complaining of recently worsening fatigue and weakness, a decreased appetite, distended abdomen, and easy bruising. His family history is notable for a mother with Hashimoto's thyroiditis, a sister with lupus and a brother with type II diabetes. On further questioning, the patient discloses a history of prior alcoholism as well as intravenous drug use, though he currently only smokes a pack per day of cigarettes. On physical exam, you note the following findings (see Figures A-C) as well as several ecchymoses and telangiectasias. As the patient has not seen a physician in many years, you obtain the following laboratory studies:

Leukocyte count: 4,100/mm^3
Hemoglobin: 9.6 g/dL
Platelet count: 87,000/mm^3
Prothrombin time (PT): 21.0 seconds
International Normalized Ratio (INR): 1.8

Serum:
Creatinine: 1.7 mg/dL
Total bilirubin: 3.2 mg/dL
Aspartate aminotransferase (AST): 225 U/L
Alanine aminotransferase (ALT): 103 U/L
Alkaline phosphatase: 162 U/L
Albumin: 2.6 g/dL
Serum thyroxine (T4): 3.1 µg/dL
Thyroid-stimulating hormone (TSH): 3.4 µU/mL

What is the cause of this patient’s low serum thyroxine?

Question:
As the patient has not seen a physician in many years, you obtain the following laboratory studies:

Leukocyte count: 4,100/mm^3
Hemoglobin: 9.6 g/dL
Platelet count: 87,000/mm^3
Prothrombin time (PT): 21.0 seconds
International Normalized Ratio (INR): 1.8

Serum:
Creatinine: 1.7 mg/dL
Total bilirubin: 3.2 mg/dL
Aspartate aminotransferase (AST): 225 U/L
Alanine aminotransferase (ALT): 103 U/L
Alkaline phosphatase: 162 U/L
Albumin: 2.6 g/dL
Serum thyroxine (T4): 3.1 µg/dL
Thyroid-stimulating hormone (TSH): 3.4 µU/mL

What is the cause of this patient’s low serum thyroxine?

Answer: Decreased liver synthetic function


Context: A 45-year-old woman, suspected of having colon cancer, is advised to undergo a contrast-CT scan of the abdomen. She has no comorbidities and no significant past medical history. There is also no history of drug allergy. However, she reports that she is allergic to certain kinds of seafood. After tests confirm normal renal function, she is taken to the CT scan room where radiocontrast dye is injected intravenously and a CT scan of her abdomen is conducted. While being transferred to her ward, she develops generalized itching and urticarial rashes, with facial angioedema. She becomes dyspneic. Her pulse is 110/min, the blood pressure is 80/50 mm Hg, and the respirations are 30/min. Her upper and lower extremities are pink and warm. What is the most appropriate management of this patient?

Question: What is the most appropriate management of this patient?

Answer: Inject epinephrine 1:1000, followed by steroids and antihistamines


Context: A 41-year-old man presents to the emergency department because of brownish discoloration of his urine for the last several days. The review of symptoms includes complaints of increasing abdominal girth, early satiety, and difficulty breathing on exertion. The past medical history includes essential hypertension for 19 years. The medication list includes lisinopril and hydrochlorothiazide. He had a right inguinal hernia repair when he was a teenager. He smokes 20–30 cigarettes daily for the last 21 years, and drinks alcohol socially. His father died of a hemorrhagic stroke at the age of 69 years. The vital signs include: temperature 37.0°C (98.6°F), blood pressure 131/88 mm Hg, and pulse 82/min. The physical examination is positive for a palpable right upper quadrant mass. The abdominal ultrasound shows multiple bilateral kidney cysts and hepatic cysts. Which of the following is the most likely diagnosis?

Question: Which of the following is the most likely diagnosis?

Answer: Autosomal dominant polycystic kidney disease


Context:
A 10-year-old boy presents to the emergency department with a swollen and painful elbow after accidentally bumping his arm into the kitchen table. His mom notes that he seems to bruise and bleed easily, but this is the first time he has had a swollen joint. She also remembers that her uncle had a bleeding disorder, but cannot remember the diagnosis. Physical exam reveals a warm and tender elbow joint, but is otherwise unremarkable. Based on clinical suspicion, a bleeding panel is ordered with the following findings:

Bleeding time: 3 minutes
Prothrombin time (PT): 13 seconds
Partial thromboplastin time (PTT): 54 seconds

Which of the following treatments would most likely be effective in preventing further bleeding episodes for this patient?

Question:
Based on clinical suspicion, a bleeding panel is ordered with the following findings:

Bleeding time: 3 minutes
Prothrombin time (PT): 13 seconds
Partial thromboplastin time (PTT): 54 seconds

Which of the following treatments would most likely be effective in preventing further bleeding episodes for this patient?

Answer: Factor VIII replacement


Context: A 35-year-old woman is involved in a car accident and presents with an open fracture of the left femur and severe bleeding from the left femoral artery. No past medical history or current medications. Her blood pressure is 90/60 mm Hg, pulse is 110/min, and respirations are 21/min. On physical examination, the patient is lethargic, confused, and poorly responds to commands. Peripheral pulses are 1+ in the left lower extremity below the level of the knee and 2+ elsewhere. When she arrives at the hospital, a stat hemoglobin level shows 6 g/dL. Which of the following is most correct about the patient’s condition?

Question: Which of the following is most correct about the patient’s condition?

Answer: This patient’s laboratory findings will likely demonstrate a normocytic anemia


Context: A 72-year-old man is brought to the emergency department after an episode of hemoptysis. He has a chronic cough that is productive of copious sputum. Six years ago, he had a stroke that left him with difficulty swallowing. He smoked one pack of cigarettes daily for 40 years, but quit 2 years ago. His respirations are 25/min and labored. Physical examination shows digital clubbing. An x-ray of the chest shows tram track opacities in the lower lung fields. Which of the following is the most likely diagnosis?

Question: Which of the following is the most likely diagnosis?

Answer: Bronchiectasis


Context: A 14-year-old boy has undergone kidney transplantation due to stage V chronic kidney disease. A pre-transplantation serologic assessment showed that he is negative for past or present HIV infection, viral hepatitis, EBV, and CMV infection. He has a known allergy for macrolides. The patient has no complaints 1 day after transplantation. His vital signs include: blood pressure 120/70 mm Hg, heart rate 89/min, respiratory rate 17/min, and temperature 37.0°C (98.6°F). On physical examination, the patient appears to be pale, his lungs are clear on auscultation, heart sounds are normal, and his abdomen is non-tender on palpation. His creatinine is 0.65 mg/dL (57.5 µmol/L), GFR is 71.3 mL/min/1.73 m2, and urine output is 0.9 mL/kg/h. Which of the following drugs should be used in the immunosuppressive regimen in this patient?

Question: Which of the following drugs should be used in the immunosuppressive regimen in this patient?

Answer: Basiliximab


Context: A 2-year-old boy presents with multiple skin abscesses caused by Staphylococcus aureus. Past medical history is significant for recurrent infections by the same organism. The nitroblue tetrazolium (NBT) test demonstrates an inability to kill microbes. Which of the following defect is most likely responsible for the findings in this patient?

Question: Which of the following defect is most likely responsible for the findings in this patient?

Answer: Inability to generate the microbicidal respiratory burst


Context: An 8-year-old boy presents to the physician with complaints that he is persistently experiencing sickness and clumsiness with multiple episodes of pneumonia and diarrhea. He also says that he has trouble seeing things well in the dark. Other symptoms include white patches (keratinized epithelium) on the sclerotic coat (protection and covering of the eyeball) and conjunctival dryness. Can you suggest the cause of these symptoms in this particular child?

Question: Can you suggest the cause of these symptoms in this particular child?

Answer: Deficiency of vitamin A


Context: A previously healthy 4-year-old boy is brought to the emergency department because of a 1-day history of pain and swelling of his left knee joint. He has not had any trauma to the knee. His family history is unremarkable except for a bleeding disorder in his maternal uncle. His temperature is 36.9°C (98.4°F). The left knee is erythematous, swollen, and tender; range of motion is limited. No other joints are affected. An x-ray of the knee shows an effusion but no structural abnormalities of the joint. Arthrocentesis is conducted. The synovial fluid is bloody. Further evaluation of this patient is most likely to show which of the following findings?

Question: Further evaluation of this patient is most likely to show which of the following findings?

Answer: Prolonged partial thromboplastin time


Context: A 30-year-old male visits you in the clinic complaining of chronic abdominal pain and diarrhea following milk intake. Gastrointestinal histology of this patient's condition is most similar to which of the following?

Question: Gastrointestinal histology of this patient's condition is most similar to which of the following?

Answer: No GI disease


Context: A 28-year-old man presents to the Emergency Department after a window he was installing fell on him. The patient complains of left ocular pain, blurred vision, and obscured lower portion of the left visual field. The patient’s vital signs are as follows: blood pressure 140/80 mm Hg, heart rate 88/min, respiratory rate 14/min, and temperature 36.9℃ (98.4℉). On physical examination, he has multiple superficial lacerations on his face, arms, and legs. Examination of his right eye shows a superficial upper eyelid laceration. Examination of the left eye shows conjunctival hyperemia, peaked pupil, iridial asymmetry, hyphema, and vitreous hemorrhage. The fundus is hard to visualize due to the vitreous hemorrhage. The visual acuity is 20/25 in the right eye and difficult to evaluate in the left. Which of the following is a proper step to undertake in the diagnosis and management of this patient?

Question: Which of the following is a proper step to undertake in the diagnosis and management of this patient?

Answer: Systemic administration of vancomycin and levofloxacin


Context: While attending a holiday party, a 35-year-old widow noticed a male who physically resembled her deceased husband. She introduced herself and began a conversation with the male while making sure not to make mention of the resemblance. After the conversation, she felt feelings of affection and warmth to the male similar to how her husband made her feel. Which of the following best explains the widow's feelings towards the male?

Question: Which of the following best explains the widow's feelings towards the male?

Answer: Transference


Context: A 54-year-old man presents to the office complaining of recent shortness of breath and fever. He has a history of a chronic cough which is progressively getting worse. His medical history is significant for hypertension and diabetes mellitus, both controlled with medication. He has been working in a sandblasting factory for over 3 decades. His temperature is 37.7°C (99.9°F), the blood pressure is 130/84 mm Hg, the pulse is 98/min, and the respiratory rate is 20/min. Chest X-ray reveals calcified hilar lymph nodes which look like an eggshell. This patient is at increased risk for which of the following conditions?

Question: This patient is at increased risk for which of the following conditions?

Answer: Mycobacterium tuberculosis infection


Context: A 24-year-old woman presents to the ED with symptoms of pelvic inflammatory disease despite being previously treated with azithromycin for chlamydial infection. Based on your clinical understanding about the epidemiology of PID, you decide to obtain a gram stain which shows a gram-negative diplococci. What is the next step in order to confirm the identity of the organism described?

Question: What is the next step in order to confirm the identity of the organism described?

Answer: Culture in Thayer-Martin media


Context: A 29-year-old mother brings in her 2-week-old baby boy to a pediatrician because he has been having difficulty feeding. The mother reveals that she had no prenatal care during her pregnancy and gave birth at home without complications. She says that her son seems to be having difficulty sucking, and she occasionally sees breast milk coming out of the infant’s nose. Physical exam reveals that this patient has a gap between his oral and nasal cavities behind the incisive foramen. He is therefore prescribed specialized bottles and his mom is taught positional techniques to ensure better feeding. Failure to fuse which of the following structures is most likely responsible for this patient's disorder?

Question: Failure to fuse which of the following structures is most likely responsible for this patient's disorder?

Answer: Palatine shelves with nasal septum


Context: A 60-year-old woman presents to the dermatologist with a lesion on her lower eyelid. She noticed it a month ago and looked like a pimple. She says that it has been bleeding lately with minimal trauma which alarmed her. She says the lesion has not grown in size and is not associated with pain or pruritus. No significant past medical history. Physical examination reveals a 0.5 cm lesion that has a pearly appearance with telangiectasia and central ulceration and curled borders. The lesion is biopsied. Histopathology reveals peripheral palisading cells with large, hyperchromatic nuclei and a high nuclear: cytoplasmic ratio. Which of the following mechanisms best describes the most common mode of spread of this patient’s neoplasm?

Question: Which of the following mechanisms best describes the most common mode of spread of this patient’s neoplasm?

Answer: Local invasion via collagenase


Context: A 65-year-old man comes to the physician for the evaluation of a 2-month history of worsening fatigue and shortness of breath on exertion. While he used to be able to walk 4–5 blocks at a time, he now has to pause every 2 blocks. He also reports waking up from having to urinate at least once every night for the past 5 months. Recently, he has started using 2 pillows to avoid waking up coughing with acute shortness of breath at night. He has a history of hypertension and benign prostatic hyperplasia. His medications include daily amlodipine and prazosin, but he reports having trouble adhering to his medication regimen. His pulse is 72/min, blood pressure is 145/90 mm Hg, and respiratory rate is 20/min. Physical examination shows 2+ bilateral pitting edema of the lower legs. Auscultation shows an S4 gallop and fine bibasilar rales. Further evaluation is most likely to show which of the following pathophysiologic changes in this patient?

Question: Further evaluation is most likely to show which of the following pathophysiologic changes in this patient?

Answer: Increased tone of efferent renal arterioles


Context:
A 17-year-old girl presents to her primary care physician for a wellness checkup. The patient is currently doing well in school and plays soccer. She has a past medical history of childhood obesity that was treated with diet and exercise. The patient states that her menses have not changed, and they occur every 1 to 3 months. Her temperature is 99.5°F (37.5°C), blood pressure is 127/70 mmHg, pulse is 90/min, respirations are 13/min, and oxygen saturation is 98% on room air. The patient's BMI at this visit is 22.1 kg/m^2. On physical exam, the patient is in no distress. You note acne present on her face, shoulders, and chest. You also note thick, black hair on her upper lip and chest. The patient's laboratory values are seen as below.

Hemoglobin: 14 g/dL
Hematocrit: 42%
Leukocyte count: 7,500/mm^3 with normal differential
Platelet count: 177,000/mm^3

Serum:
Na+: 137 mEq/L
Cl-: 101 mEq/L
K+: 4.4 mEq/L
HCO3-: 24 mEq/L
BUN: 27 mg/dL
Glucose: 90 mg/dL
Creatinine: 1.0 mg/dL
Ca2+: 10.1 mg/dL
Testosterone: 82 ng/dL
17-hydroxyprogesterone: elevated
AST: 12 U/L
ALT: 10 U/L

Which of the following is associated with this patient's most likely diagnosis?

Question:
Hemoglobin: 14 g/dL
Hematocrit: 42%
Leukocyte count: 7,500/mm^3 with normal differential
Platelet count: 177,000/mm^3

Serum:
Na+: 137 mEq/L
Cl-: 101 mEq/L
K+: 4.4 mEq/L
HCO3-: 24 mEq/L
BUN: 27 mg/dL
Glucose: 90 mg/dL
Creatinine: 1.0 mg/dL
Ca2+: 10.1 mg/dL
Testosterone: 82 ng/dL
17-hydroxyprogesterone: elevated
AST: 12 U/L
ALT: 10 U/L

Which of the following is associated with this patient's most likely diagnosis?

Answer: Deficiency of 21-hydroxylase


Context: A medical technician is trying to isolate a pathogen from the sputum sample of a patient. The sample is heat fixed to a slide then covered with carbol fuchsin stain and heated again. After washing off the stain with clean water, the slide is covered with sulfuric acid. The sample is rinsed again and stained with methylene blue. Microscopic examination shows numerous red organisms. Which of the following is the most likely isolated pathogen?

Question: Which of the following is the most likely isolated pathogen?

Answer: Nocardia asteroides


Context:
A 24-year-old woman with 45,X syndrome comes to the physician because of diarrhea for 4 months. She also reports bloating, nausea, and abdominal discomfort that persists after defecation. For the past 6 months, she has felt tired and has been unable to do her normal chores. She went on a backpacking trip across Southeast Asia around 7 months ago. She is 144 cm (4 ft 9 in) tall and weighs 40 kg (88 lb); BMI is 19 kg/m2. Her blood pressure is 110/60 mm Hg in the upper extremities and 80/40 mm Hg in the lower extremities. Examination shows pale conjunctivae and angular stomatitis. Abdominal examination is normal. Laboratory studies show:
Hemoglobin 9.1 mg/dL
Leukocyte count 5100/mm3
Platelet count 200,000/mm3
Mean corpuscular volume 67 μmm3
Serum
Na+ 136 mEq/L
K+ 3.7 mEq/L
Cl- 105 mEq/L
Glucose 89 mg/dL
Creatinine 1.4 mg/dL
Ferritin 10 ng/mL
IgA tissue transglutaminase antibody positive
Based on the laboratory studies, a biopsy for confirmation of the diagnosis is suggested, but the patient is unwilling to undergo the procedure. Which of the following is the most appropriate next step in management of this patient's gastrointestinal symptoms?"

Question: Which of the following is the most appropriate next step in management of this patient's gastrointestinal symptoms?"

Answer: Gluten-free diet


Context: A 55-year-old man presents with severe fatigue and fever. His past medical history is significant for a recent history of mononucleosis from which he fully recovered 8 weeks ago. On physical examination, the patient seems pale. A chest radiograph shows multiple enlarged mediastinal lymph nodes. A biopsy of one of the enlarged mediastinal lymph nodes is performed and shows the presence of multinucleated cells with an ‘owl-eye’ appearance in a hypocellular background. This patient’s most likely condition is very aggressive and associated with a very poor prognosis. Which of the following is the most likely diagnosis in this patient?

Question: Which of the following is the most likely diagnosis in this patient?

Answer: Lymphocyte-depleted lymphoma


Context: A 36-year-old woman presents to the emergency department with chest discomfort and fatigue. She reports that her symptoms began approximately 1 week ago and are associated with shortness of breath, swelling of her legs, and worsening weakness. She’s been having transitory fevers for about 1 month and denies having similar symptoms in the past. Medical history is significant for systemic lupus erythematosus (SLE) treated with hydroxychloroquine. She had a SLE flare approximately 2 weeks prior to presentation, requiring a short course of prednisone. Physical exam was significant for a pericardial friction rub. An electrocardiogram showed widespread ST-segment elevation and PR depression. After extensive work-up, she was admitted for further evaluation, treatment, and observation. Approximately 2 days after admission she became unresponsive. Her temperature is 100°F (37.8°C), blood pressure is 75/52 mmHg, pulse is 120/min, and respirations are 22/min. Heart sounds are muffled. Which of the following is a clinical finding that will most likely be found in this patient?

Question: Which of the following is a clinical finding that will most likely be found in this patient?

Answer: Jugular venous distension


Context: A 28-year-old woman is brought to the physician because of progressive difficulty walking, slowed speech, and a tremor for the past 5 months. Her grandfather died of bleeding esophageal varices at the age of 42 years. She does not drink alcohol. She is alert and oriented but has a flat affect. Her speech is slurred and monotonous. Examination shows a broad-based gait and a low-frequency tremor of her left hand. Abdominal examination shows hepatosplenomegaly. A photograph of the patient's right eye is shown. Further evaluation of this patient is most likely to show which of the following findings?

Question: Further evaluation of this patient is most likely to show which of the following findings?

Answer: Low serum ceruloplasmin concentration


Context: A 65-year-old man presents to his primary care provider with excessive fatigue, weight loss, and multiple small bruises on his arms and abdomen. These symptoms started several months ago. He reports worsening fatigue and a 20-pound (9 kg) weight loss in the past month. Past medical history is significant for an asymptomatic lymphocytosis noted 6 months ago on a yearly physical. On review of systems, he denies chest pain, difficulty breathing, swelling in the extremities, or change in bowel habits. Vitals include: temperature 37.0°C (98.6°F), blood pressure 110/75 mm Hg, pulse 99/min, respirations 20/min, and oxygen saturation 91% on room air. On physical exam, the patient is listless. The cardiac exam is normal. Lungs are clear to auscultation. The abdominal exam is significant for mild splenomegaly. Scleral icterus is present and there is prominent generalized non-tender lymphadenopathy. Which of the following laboratory findings is best associated with this patient’s condition?

Question: Which of the following laboratory findings is best associated with this patient’s condition?

Answer: Positive direct Coombs tests


Context: A 42-year-old homeless man is brought to the emergency room after he was found unconscious in a park. He has alcohol on his breath and is known to have a history of chronic alcoholism. A noncontrast CT scan of the head is normal. The patient is treated for acute alcohol intoxication and admitted to the hospital. The next day, the patient demands to be released. His vital signs are a pulse 120/min, a respiratory rate 22/min, and blood pressure 136/88 mm Hg. On physical examination, the patient is confused, agitated, and sweating profusely, particularly from his palms. Generalized pallor is present. What is the mechanism of action of the drug recommended to treat this patient’s most likely condition?

Question: What is the mechanism of action of the drug recommended to treat this patient’s most likely condition?

Answer: It increases the frequency of GABA-gated chloride channel opening.


Context: A 3-year-old boy was brought in by his parents for undescended testes. The physical examination showed an absence of the left testis in the scrotum. Inguinal swelling was noted on the left side and was surgically corrected. Which of the following conditions will most likely occur in the later stages of his life?

Question: Which of the following conditions will most likely occur in the later stages of his life?

Answer: Testicular cancer


Context: A 70-year-old woman is brought to the emergency department 1 hour after being found unconscious in her apartment by her neighbor. No medical history is currently available. Her temperature is 37.2°C (99.0°F), pulse is 120/min, respirations are 18/min, and blood pressure is 70/50 mm Hg. Laboratory studies show a glomerular filtration rate of 70 mL/min/1.73 m2 (N > 90) and an increased filtration fraction. Which of the following is the most likely cause of this patient's findings?

Question: Which of the following is the most likely cause of this patient's findings?

Answer: Profuse diarrhea


Context: A 21-year-old woman presents to the clinic complaining of fatigue for the past 2 weeks. She reports that it is difficult for her to do strenuous tasks such as lifting heavy boxes at the bar she works at. She denies any precipitating factors, weight changes, nail changes, dry skin, chest pain, abdominal pain, or urinary changes. She is currently trying out a vegetarian diet for weight loss and overall wellness. Besides heavier than usual periods, the patient is otherwise healthy with no significant medical history. A physical examination demonstrates conjunctival pallor. Where in the gastrointestinal system is the most likely mineral that is deficient in the patient absorbed?

Question: Where in the gastrointestinal system is the most likely mineral that is deficient in the patient absorbed?

Answer: Duodenum


Context: A 42-year-old woman comes to the emergency department because of worsening severe pain, swelling, and stiffness in her right knee for the past 2 days. She recently started running 2 miles, 3 times a week in an attempt to lose weight. She has type 2 diabetes mellitus and osteoporosis. Her mother has rheumatoid arthritis. She drinks one to two glasses of wine daily. She is sexually active with multiple partners and uses condoms inconsistently. Current medications include metformin and alendronate. She is 161 cm (5 ft 3 in) tall and weighs 74 kg (163 lb); BMI is 29 kg/m2. Her temperature is 38.3°C (100.9°F), pulse is 74/min, and blood pressure is 115/76 mm Hg. She appears to be in discomfort and has trouble putting weight on the affected knee. Physical examination shows a 2-cm, painless ulcer on the plantar surface of the right toe. The right knee is swollen and tender to palpation. Arthrocentesis of the right knee with synovial fluid analysis shows a cell count of 55,000 WBC/μL with 77% polymorphonuclear (PMN) cells. Which of the following is the most likely underlying cause of this patient's presenting condition?

Question: Which of the following is the most likely underlying cause of this patient's presenting condition?

Answer: Hematogenous spread of infection


Context:
A four-week-old female is evaluated in the neonatal intensive care unit for feeding intolerance with gastric retention of formula. She was born at 25 weeks gestation to a 32-year-old gravida 1 due to preterm premature rupture of membranes at 24 weeks gestation. The patient’s birth weight was 750 g (1 lb 10 oz). She required resuscitation with mechanical ventilation at the time of delivery, but she was subsequently extubated to continuous positive airway pressure (CPAP) and then weaned to nasal cannula. The patient was initially receiving both parenteral nutrition and enteral feeds through a nasogastric tube, but she is now receiving only continuous nasogastric formula feeds. Her feeds are being advanced to a target weight gain of 20-30 g per day. Her current weight is 1,350 g (2 lb 16 oz). The patient’s temperature is 97.2°F (36.2°C), blood pressure is 72/54 mmHg, pulse is 138/min, respirations are 26/min, and SpO2 is 96% on 4L nasal cannula. On physical exam, the patient appears lethargic. Her abdomen is soft and markedly distended. Digital rectal exam reveals stool streaked with blood in the rectal vault.

Which of the following abdominal radiographs would most likely be seen in this patient?

Question: Which of the following abdominal radiographs would most likely be seen in this patient?

Answer: D


Context: A 48-year-old Caucasian woman presents to her primary care provider complaining about difficulties while swallowing with fatigability and occasional palpitations for the past few weeks. Her personal history is relevant for bariatric surgery a year ago and a long list of allergies which includes peanuts, penicillin, and milk protein. Physical examination is unremarkable except for pale skin and mucosal surfaces, koilonychia, and glossitis. Which of the following descriptions would you expect to find in an endoscopy?

Question: Which of the following descriptions would you expect to find in an endoscopy?

Answer: Luminal eccentric membranes


Context: A 72-year-old man is admitted to the hospital because of a 2-day history of right-sided weakness and dysphagia. He is diagnosed with a thrombotic stroke and treatment with aspirin is initiated. A videofluoroscopic swallowing study is performed to determine his ability to swallow safely; he is found to be at increased risk of aspiration. Consequently, he is ordered not to have any food or liquids by mouth. A Dobhoff feeding tube is placed, tube feedings are ordered, and the patient starts receiving tube feedings. Shortly after, he develops a cough and dyspnea. An x-ray of the chest shows opacification of the right lower lobe and that the end of the Dobhoff tube is in his right lung instead of his stomach. Which of the following would most likely have prevented this medical error from occurring?

Question: Which of the following would most likely have prevented this medical error from occurring?

Answer: Checklist


Context:
A 20-year-old woman presents with shortness of breath and chest pain for 1 week. She says the chest pain is severe, sharp in character, and aggravated upon deep breathing. She says she becomes short of breath while walking upstairs in her home or with any type of exertion. She says she frequently feels feverish and fatigued. No significant past medical history and no current medications. Review of systems is significant for a weight loss of 4.5 kg (10.0 lb) over the past month and joint pain in her wrists, hands, and knees. Vital signs are within normal limits. On physical examination, there is a pink rash over her face which is aggravated by sunlight (shown in the image). There are decreased breath sounds on the right. A chest radiograph reveals evidence of a right-sided pleural effusion. Routine urinalysis and urine dipstick are normal. Serum antinuclear antibody (ANA) and anti-double-stranded DNA levels are positive. The patient is started on prednisone therapy and 2 weeks later her CBC is obtained and compared to the one on admission:
On admission
Leukocytes 8,000/mm3
Neutrophils 60%
Lymphocytes 23%
Eosinophils 2%
Basophils 1%
Monocyte 5%
Hemoglobin 10 g/dL
Creatinine 0.8 mg/dL
BUN 15 mg/dL
2 weeks later
Leukocytes 13,000/mm3
Neutrophils 90%
Lymphocytes 8%
Eosinophils 0%
Basophils 0%
Monocyte 1%
Hemoglobin 12g/dL
Creatinine 0.8 mg/dL
BUN 15 mg/dL
Which of the following best describes the most likely mechanism that accounts for the difference between these 2 complete blood counts (CBCs)?

Question:
The patient is started on prednisone therapy and 2 weeks later her CBC is obtained and compared to the one on admission:
On admission
Leukocytes 8,000/mm3
Neutrophils 60%
Lymphocytes 23%
Eosinophils 2%
Basophils 1%
Monocyte 5%
Hemoglobin 10 g/dL
Creatinine 0.8 mg/dL
BUN 15 mg/dL
2 weeks later
Leukocytes 13,000/mm3
Neutrophils 90%
Lymphocytes 8%
Eosinophils 0%
Basophils 0%
Monocyte 1%
Hemoglobin 12g/dL
Creatinine 0.8 mg/dL
BUN 15 mg/dL
Which of the following best describes the most likely mechanism that accounts for the difference between these 2 complete blood counts (CBCs)?

Answer: Downregulation of neutrophil adhesion molecules


Context: A 44-year-old woman presents to her primary care physician because she has been experiencing shortness of breath and fatigue over the past week. In addition, she has noticed that her eyelids appear puffy and her lower extremities have become swollen. Laboratory tests reveal protein and fatty casts in her urine. Based on these findings, a kidney biopsy is obtained and has a granular appearance on immunofluorescence with subepithelial deposits on electron microscopy. Which of the following is associated with the most likely cause of this patient's symptoms?

Question: Which of the following is associated with the most likely cause of this patient's symptoms?

Answer: Phospholipase A2 receptor antibodies


Context:
A 42-year-old man presents to his primary care physician complaining of subjective fever, cough, and night sweats. He states that over the past 2 months he has “not felt like myself.” He has lost 12 lbs over this time period. Two weeks ago, he started experiencing night sweats and cough. This morning he decided to take his temperature and reports it was “high.” He has a history of HIV and admits to inconsistently taking his anti-retrovirals. A chest radiograph reveals a cavitary lesion in the left upper lobe. An interferon-gamma release assay is positive, and the patient is started on appropriate antimicrobial therapy. A month later he is seen in clinic for follow-up. Lab work is obtained, as shown below:

Leukocyte count: 11,000/mm^3 with normal differential
Hemoglobin: 9.2 g/dL
Platelet count: 400,000/mm^3
Mean corpuscular volume (MCV): 75 µm^3

Based on these results, a peripheral smear is sent and shows Pappenheimer bodies. Which of the following is the most accurate test for the patient’s diagnosis?

Question: Which of the following is the most accurate test for the patient’s diagnosis?

Answer: Prussian blue staining


Context: The prison doctor sees a 25-year-old man for some minor injuries sustained during a recent lunchroom brawl. The patient has a long history of getting into trouble. During his interview, he seems very charming and carefully deflects all responsibility to others and gets irritable and hostile once probed on the issues. He is married and has 2 young children for whom he does not pay child support. Which of the following details is most critical for diagnosing this patient’s condition?

Question: Which of the following details is most critical for diagnosing this patient’s condition?

Answer: Childhood history


Context: A 52-year-old man presents to his physician with a chief concern of not feeling well. The patient states that since yesterday he has experienced nausea, vomiting, diarrhea, general muscle cramps, a runny nose, and aches and pains in his muscles and joints. The patient has a past medical history of obesity, chronic pulmonary disease, lower back pain, and fibromyalgia. His current medications include varenicline, oxycodone, and an albuterol inhaler. The patient is requesting antibiotics and a refill on his current medications at this visit. He works at a local public school and presented with a similar chief complaint a week ago, at which time he had his prescriptions refilled. You have also seen several of his coworkers this past week and sent them home with conservative measures. Which of the following is the best next step in management?

Question: Which of the following is the best next step in management?

Answer: Methadone


Context:
A 60-year-old woman presents to the physician with a 2-day history of fever and painful swelling of the left knee. She was diagnosed with rheumatoid arthritis about 15 years ago and has a 7-year history of diabetes mellitus. Over the past year, she has been admitted to the hospital twice for acute, painful swelling of the knees and hands. She is on insulin therapy and takes methotrexate, metformin, aspirin, and prednisolone 5 mg/day. Her temperature is 38.5°C (101.3°F), pulse is 86/min, respirations are 14/min, and blood pressure is 125/70 mm Hg. A finger-stick glucose test shows 230 mg/dL. Her left knee is diffusely swollen, warm, and painful on both active and passive motion. There is evidence of deformity in several small joints of the hands and feet without any acute swelling or pain. Physical examination of the lungs, abdomen, and perineum shows no abnormalities. The synovial fluid analysis shows the following:
Color turbid, purulent, gray
Viscosity reduced
WBC 25,000/µL–250,000/µL
Neutrophils > 90%
Crystals may be present (presence indicates coexistence, but does not rule out infection)
Which of the following is the most appropriate initial pharmacotherapy in this patient?

Question:
The synovial fluid analysis shows the following:
Color turbid, purulent, gray
Viscosity reduced
WBC 25,000/µL–250,000/µL
Neutrophils > 90%
Crystals may be present (presence indicates coexistence, but does not rule out infection)
Which of the following is the most appropriate initial pharmacotherapy in this patient?

Answer: Intravenous vancomycin


Context: A 26-year-old woman at 30 weeks 2 days of gestational age is brought into the emergency room following a seizure episode. Her medical records demonstrate poorly controlled gestational hypertension. Following administration of magnesium, she is taken to the operating room for emergency cesarean section. Her newborn daughter’s APGAR scores are 7 and 9 at 1 and 5 minutes, respectively. The newborn is subsequently taken to the NICU for further management and monitoring. Ten days following birth, the baby begins to refuse formula feedings and starts having several episodes of bloody diarrhea despite normal stool patterns previously. Her temperature is 102.2°F (39°C), blood pressure is 84/53 mmHg, pulse is 210/min, respirations are 53/min, and oxygen saturation is 96% on room air. A physical examination demonstrates a baby in mild respiratory distress and moderate abdominal distention. What do you expect to find in this patient?

Question: What do you expect to find in this patient?

Answer: Gas within the walls of the small or large intestine on radiograph


Context: A 12-year-old boy presents with progressive clumsiness and difficulty walking. He walks like a 'drunken-man' and has experienced frequent falls. He was born at term and has gone through normal developmental milestones. His vaccination profile is up to date. He denies fever, chills, nausea, vomiting, chest pain, and shortness of breath. He has no history of alcohol use or illicit drug use. His elder brother experienced the same symptoms. The physical examination reveals normal higher mental functions. His extraocular movements are normal. His speech is mildly dysarthric. His muscle tone and strength in all 4 limbs are normal. His ankle reflexes are absent bilaterally with positive Babinski’s signs. Both vibration and proprioception are absent bilaterally. When he is asked to stand with his eyes closed and with both feet close together, he sways from side to side, unable to stand still. X-ray results show mild scoliosis. Electrocardiogram results show widespread T-wave inversions. His fasting blood glucose level is 143 mg/dL. What is the most likely diagnosis?

Question: What is the most likely diagnosis?

Answer: Friedreich’s ataxia


Context: A 55-year-old man presents to the emergency department because of an excruciating headache that started suddenly after he got home from work. He also reports having double vision. Specifically, in the last week he almost got into two car accidents with vehicles that "came out of nowhere" while he was trying to merge on the highway. Physical examination is notable for ptosis of the left eye, which is also inferiorly and laterally deviated. The patient is treated emergently and then started on a hormone replacement in order to avoid life-threatening post-treatment complications. The patient's current presentation was associated with a pathologic process that existed for several months prior to this event. Which of the following symptoms could this patient have experienced as part of that pre-existing pathology?

Question: Which of the following symptoms could this patient have experienced as part of that pre-existing pathology?

Answer: Increased hat size


Context: A 49-year-old man is brought to the emergency department by his wife because he is vomiting blood. His wife reports that he has been nauseous for the past day and that he has had 2 episodes of vomiting bright red blood over the past 2 hours. He has never experienced this before. He has not had any bloody stool, melena, or abdominal pain. He was diagnosed with alcoholic cirrhosis 6 months ago. He drank approximately 1 liter of vodka over the past day, which is typical for him. He takes no medications. He is confused and disoriented to place and time. Physical examination shows ascites. Vital signs are within normal limits. His hemoglobin concentration is 9.5 g/dL. Intravenous fluid resuscitation is begun. He starts to vomit bright red blood again intermittently, which continues for 10 minutes. When vital signs are measured again, his pulse is 95/min and blood pressure is 109/80 mm/Hg. Which of the following is the most appropriate initial step in management?

Question: Which of the following is the most appropriate initial step in management?

Answer: Perform endotracheal intubation


Context: A 30-year-old woman is undergoing work up for progressive weakness. She reports that at the end of the work day, her "eyelids droop" and her "eyes cross," but in the morning she feels "ok." She reports that her legs feel heavy when she climbs the stairs of her house to go to sleep at night. As part of her work up, the physician has her hold her gaze toward the ceiling, and after a minute, her lids become ptotic. She is given an IV medication and her symptoms resolve, but return 10 minutes later. Which of the following medications was used in the diagnostic test performed for this patient?

Question: Which of the following medications was used in the diagnostic test performed for this patient?

Answer: Edrophonium


Context: A drug that inhibits mRNA synthesis has the well-documented side effect of red-orange body fluids. For which of the following is this drug used as monotherapy?

Question: For which of the following is this drug used as monotherapy?

Answer: Neisseria meningitidis prophylaxis


Context: A 50-year-old man is brought to the emergency department due to chest pain and shortness of breath for the last 2 hours. He describes the chest pain as squeezing in nature and radiating towards his left arm. It is associated with nausea and sweating. He has a similar history in the past, which is mostly aggravated with strenuous activities and relieved with sublingual nitroglycerin. He has a history of uncontrolled diabetes and hypercholesterolemia for the last 10 years. His last HbA1c was 8.0 %. His blood pressure is 150/90 mm Hg, pulse rate is 90/min, respiratory rate is 20/min, and temperature is 36.8°C (98.3°F). Oxygen saturation in room air is 98%. ECG shows ST-segment elevation in leads I, II, and aVF. He is being prepared for coronary angioplasty. Elevation in which of the following enzymes is most significant in the diagnosis of this patient?

Question: Elevation in which of the following enzymes is most significant in the diagnosis of this patient?

Answer: Troponin I


Context: A 10-year-old boy is brought by his mother to his pediatrician for “skin growths.” His mother reports that she started noticing small lumps arising from the patient’s lips and eyelids several months ago. She also notes that he seems to suffer from frequent constipation and appears “weaker” than many of his peers. The boy’s past medical history is unremarkable. His maternal aunt, maternal uncle, and maternal grandmother have a history of colorectal cancer and his father and paternal grandmother have a history of thyroid cancer. His height and weight are in the 85th and 45th percentiles, respectively. His temperature is 99°F (37.1°C), blood pressure is 110/65 mmHg, pulse is 90/min, and respirations are 18/min. On examination, he has an elongated face with protruding lips. There are numerous sessile painless nodules on the patient’s lips, tongue, and eyelids. This patient’s condition is most strongly associated with a mutation in which of the following genes?

Question: This patient’s condition is most strongly associated with a mutation in which of the following genes?

Answer: RET


Context: A 50-year-old man presents with a 3-day history of painful peeling of his skin. He says he initially noted small erythematous spots on areas of his neck, but this quickly spread to his torso, face, and buttocks to form flaccid blisters and areas of epidermal detachment involving > 40% of his total body surface area. He describes the associated pain as severe, burning, and generalized over his entire body. The patient does recall having an episode with similar symptoms 10 years ago after taking an unknown antibiotic for community-acquired pneumonia, but the symptoms were nowhere near this severe. He denies any fever, chills, palpitations, dizziness, or trouble breathing. Past medical history is significant for a urinary tract infection (UTI) diagnosed 1 week ago for which he has been taking ciprofloxacin. His vital signs include: blood pressure, 130/90 mm Hg; temperature, 37.7℃ (99.9℉); respiratory, rate 22/min; and pulse, 110/min. On physical examination, the patient is ill-appearing and in acute distress due to pain. The epidermis sloughing involves areas of the face, back, torso, buttocks, and thighs bilaterally, and its appearance is shown in the exhibit (see image). Nikolsky sign is positive. Laboratory findings are unremarkable. Which of the following is the next best diagnostic step in this patient?

Question: Which of the following is the next best diagnostic step in this patient?

Answer: Skin biopsy and histopathologic analysis


Context: A 25-year-old woman comes to the physician for a pre-employment examination. Her current medications include an oral contraceptive and a daily multivitamin. Physical examination is unremarkable. Serum studies show calcium of 11.8 mg/dL, phosphorus of 2.3 mg/dL, and parathyroid hormone level of 615 pg/mL. A 24-hour urine collection shows a low urinary calcium level. Which of the following is the most likely underlying cause of this patient’s laboratory findings?

Question: Which of the following is the most likely underlying cause of this patient’s laboratory findings?

Answer: Defect in calcium-sensing receptors


Context:
A 5-year-old boy presents to his pediatrician with weakness. His father observed that his son seemed less energetic at daycare and kindergarten classes. He was becoming easily fatigued from mild play. His temperature is 98°F (37°C), blood pressure is 90/60 mmHg, pulse is 100/min, and respirations are 20/min. Physical exam reveals pale conjunctiva, poor skin turgor and capillary refill, and cervical and axillary lymphadenopathy with assorted bruises throughout his body. A complete blood count reveals the following:

Leukocyte count: 3,000/mm^3
Segmented neutrophils: 30%
Bands: 5%
Eosinophils: 5%
Basophils: 10%
Lymphocytes: 40%
Monocytes: 10%

Hemoglobin: 7.1 g/dL
Hematocrit: 22%
Platelet count: 50,000/mm^3

The most specific diagnostic assessment would most likely show which of the following?

Question:
A complete blood count reveals the following:

Leukocyte count: 3,000/mm^3
Segmented neutrophils: 30%
Bands: 5%
Eosinophils: 5%
Basophils: 10%
Lymphocytes: 40%
Monocytes: 10%

Hemoglobin: 7.1 g/dL
Hematocrit: 22%
Platelet count: 50,000/mm^3

The most specific diagnostic assessment would most likely show which of the following?

Answer: Bone marrow biopsy with > 25% lymphoblasts


Context: A 57-year-old woman with a history of diabetes and hypertension accidentally overdoses on antiarrhythmic medication. Upon arrival in the ER, she is administered a drug to counteract the effects of the overdose. Which of the following matches an antiarrhythmic with its correct treatment in overdose?

Question: Which of the following matches an antiarrhythmic with its correct treatment in overdose?

Answer: Esmolol and glucagon


Context: You are seeing a patient in clinic who presents with complaints of weakness. Her physical exam is notable for right sided hyperreflexia, as well as the finding in video V. Where is the most likely location of this patient's lesion?

Question: Her physical exam is notable for right sided hyperreflexia, as well as the finding in video V. Where is the most likely location of this patient's lesion?

Answer: Internal capsule


Context:
An 8-year-old female presents to her pediatrician with nasal congestion. Her mother reports that the patient has had nasal congestion and nighttime cough for almost two weeks. The patient’s 3-year-old brother had similar symptoms that began around the same time and have since resolved. The patient initially seemed to be improving, but four days ago she began developing worsening nasal discharge and fever to 102.6°F (39.2°C) at home. Her mother denies any change in appetite. The patient denies sore throat, ear pain, and headache. She is otherwise healthy. In the office, her temperature is 102.2°F (39.0°C), blood pressure is 96/71 mmHg, pulse is 128/min, and respirations are 18/min. On physical exam, the nasal turbinates are edematous and erythematous. She has a dry cough. Purulent mucous can be visualized dripping from the posterior nasopharynx. Her maxillary sinuses are tender to palpation.

Which of the following organisms is most likely to be causing this patient’s current condition?

Question: Which of the following organisms is most likely to be causing this patient’s current condition?

Answer: Moraxella catarrhalis


Context: A 25-year-old female comes to the physician because of fever and worsening cough for the past 4-days. She has had several episodes of otitis media, sinusitis, and an intermittent cough productive of green sputum for the past 2-years. She has also noticed some streaks of blood in the sputum lately. Her temperature is 38°C (100.4°F). Auscultation of the chest reveals crackles and rhonchi bilaterally. Heart sounds cannot be heard along the left lower chest. A CT scan of the chest reveals bronchiectasis and dextrocardia. Which of the following additional findings is most likely in this patient?

Question: Which of the following additional findings is most likely in this patient?

Answer: Delayed tubal ovum transit


Context:
A 6-day-old boy is brought to the emergency room with a fever. He was born to a G1P1 mother at 39 weeks gestation via vaginal delivery. The mother underwent all appropriate prenatal care and was discharged from the hospital 1 day after birth. The boy has notable skin erythema around the anus with some serosanguinous fluid. The umbilical stump is present. The patient is discharged from the emergency room with antibiotics. He returns to the emergency room at 32 days of age and his mother reports that he has been clutching his left ear. The left tympanic membrane appears inflamed and swollen. The umbilical stump is still attached and is indurated, erythematous, and swollen. The boy's temperature is 99°F (37.2°C), blood pressure is 100/60 mmHg, pulse is 130/min, and respirations are 20/min. A complete blood count is shown below:

Hemoglobin: 14.0 g/dL
Hematocrit: 42%
Leukocyte count: 16,000/mm^3 with normal differential
Platelet count: 190,000/mm^3

A deficiency in which of the following compounds is most likely the cause of this patient's condition?

Question:
A complete blood count is shown below:

Hemoglobin: 14.0 g/dL
Hematocrit: 42%
Leukocyte count: 16,000/mm^3 with normal differential
Platelet count: 190,000/mm^3

A deficiency in which of the following compounds is most likely the cause of this patient's condition?

Answer: LFA-1 integrin


Context: The boy is admitted to the pediatric intensive care unit for closer monitoring. Peripheral venous access is established. He is treated with IV isotonic saline and started on an insulin infusion. This patient is at the highest risk for which of the following conditions in the next 24 hours?

Question: This patient is at the highest risk for which of the following conditions in the next 24 hours?

Answer: Cerebral edema


Context: A 70-year-old man presents to the physician with a 1-month history of severe fatigue. During this time, he has unintentionally lost 2 kg (4.4 lb). Currently, he takes no medications other than aspirin for occasional knee pain. He does not smoke or drink alcohol. His vital signs are within the normal range. On physical examination, the conjunctivae are pale. Petechiae are present on the distal lower extremities and on the soft and hard palates. Palpation reveals bilateral painless cervical lymphadenopathy. Examination of the lungs, heart, and abdomen shows no abnormalities. Which of the following factors in this patient’s history or laboratory findings would most likely indicate a good prognosis?

Question: Which of the following factors in this patient’s history or laboratory findings would most likely indicate a good prognosis?

Answer: Translocation t(15;17)


Context: An 11-month-old boy presents to his pediatrician with severe wheezing, cough, and fever of 38.0°C (101.0°F). Past medical history is notable for chronic diarrhea since birth, as well as multiple pyogenic infections. The mother received prenatal care, and delivery was uneventful. Both parents, as well as the child, are HIV-negative. Upon further investigation, the child is discovered to have Pneumocystis jirovecii pneumonia, and the appropriate treatment is begun. Additionally, a full immunologic check-up is ordered. Which of the following profiles is most likely to be observed in this patient?

Question: Which of the following profiles is most likely to be observed in this patient?

Answer: Increased IgM and decreased IgA, IgG, and IgE


Context:
A 76-year-old man presents after an acute onset seizure. He lives in a retirement home and denies any previous history of seizures. Past medical history is significant for a hemorrhagic stroke 4 years ago, and type 2 diabetes, managed with metformin. His vital signs include: blood pressure 80/50 mm Hg, pulse 80/min, and respiratory rate 19/min. On physical examination, the patient is lethargic. Mucous membranes are dry. A noncontrast CT of the head is performed and is unremarkable. Laboratory findings are significant for the following:
Plasma glucose 680 mg/dL
pH 7.37
Serum bicarbonate 17 mEq/L
Effective serum osmolality 350 mOsm/kg
Urinary ketone bodies negative
Which of the following was the most likely trigger for this patient’s seizure?

Question:
Laboratory findings are significant for the following:
Plasma glucose 680 mg/dL
pH 7.37
Serum bicarbonate 17 mEq/L
Effective serum osmolality 350 mOsm/kg
Urinary ketone bodies negative
Which of the following was the most likely trigger for this patient’s seizure?

Answer: Reduced fluid intake


Context:
A 64-year-old woman comes to the physician because of a 7.2-kg (16-lb) weight loss over the past 6 months. For the last 4 weeks, she has also had intermittent constipation and bloating. Four months ago, she spent 2 weeks in Mexico with her daughter. She has never smoked. She drinks one glass of wine daily. She appears thin. Her temperature is 38.3°C (101°F), pulse is 80/min, and blood pressure is 136/78 mm Hg. The lungs are clear to auscultation. The abdomen is distended and the liver is palpable 4 cm below the right costal margin with a hard, mildly tender nodule in the left lobe. Test of the stool for occult blood is positive. Serum studies show:
Alkaline phosphatase 67 U/L
AST 65 U/L
ALT 68 U/L
Hepatitis B surface antigen negative
Hepatitis C antibody negative
A contrast-enhanced CT scan of the abdomen is shown. Which of the following is the most likely diagnosis?"

Question: Which of the following is the most likely diagnosis?"

Answer: Metastatic colorectal cancer


Context: A 52-year-old African American man presents to his primary care physician with a chief complaint of leg swelling. He says that the swelling began about 2 weeks ago and he cannot recall anything that may have provoked the episode. Otherwise he has had joint pain, headaches, frothy urine, and some tingling in his fingers and toes though he doesn't feel that any of this is related to his swelling. He denies any shortness of breath, back pain, or skull pain. His past medical history is significant for mild rheumatoid arthritis, diabetes, and hypertension all of which are well controlled. Physical exam reveals 3+ pitting edema in his legs bilaterally. A chest radiograph reveals mild enlargement of the cardiac shadow. Urinalysis reveals 3+ protein and casts with a cross appearance under polarized light. A renal biopsy is taken with a characteristic finding seen only under polarized light. Which of the following is associated with the most likely cause of this patient's edema?

Question: Which of the following is associated with the most likely cause of this patient's edema?

Answer: Elevated levels of IL-6


Context: A 10-month-old girl is brought to the clinic by her mother with skin lesions on her chest. The mother says that she noticed the lesions 24 hours ago and that they have not improved. The patient has no significant past medical history. She was born at term by spontaneous transvaginal delivery with no complications, is in the 90th percentile on her growth curve, and has met all developmental milestones. Upon physical examination, several skin-colored umbilicated papules are visible. Which of the following is the most appropriate treatment of this patient's likely diagnosis?

Question: Which of the following is the most appropriate treatment of this patient's likely diagnosis?

Answer: Cryotherapy or podophyllotoxin (0.15% topically)


Context: A 67-year-old female patient is brought to the emergency department after her daughter noticed she has been having meaningless speech. When assessing the patient, she calls the chair a table, and at times would make up new words. She does not appear to be aware of her deficit, and is carrying on an empty conversation. Her speech is fluent, but with paraphasic errors. Her repetition is impaired. On physical examination, a right upper quadrant field-cut is appreciated, with impairment in comprehension and repetition. Which of the following structures is most likely involved in this patient’s presentation?

Question: Which of the following structures is most likely involved in this patient’s presentation?

Answer: Superior temporal gyrus


Context: A researcher has identified a chemical compound that she expects may contribute to the development of colorectal cancer. She designs an experiment where she exposes 70 mice to a diet containing this compound with another 50 mice in a control group that was fed a regular diet. After 9 months, the mice were evaluated for tumor development at necropsy. In total, 14 mice in the experimental group developed colorectal tumor burden, and 1 mouse in the control group developed tumors. Based on this experiment, what risk of colorectal cancer can be attributable to this chemical compound?

Question: Based on this experiment, what risk of colorectal cancer can be attributable to this chemical compound?

Answer: 18.0%


Context: A 65-year-old man presents to his primary care physician for a rash. He states that for the past several days he has felt burning and itching around his eye. Yesterday, he noticed that a rash had formed. Review of systems is notable for mild diarrhea for the past week. The patient has a past medical history of diabetes, asthma, seasonal allergies, and hypertension. He is not currently taking any medications. Physical exam is notable for a vesicular rash surrounding the orbit. Which of the following is the best next step in management?

Question: Which of the following is the best next step in management?

Answer: Acyclovir


Context: A 66-year-old woman presents to the emergency department after a fall 4 hours ago. She was on her way to the bathroom when she fell to the ground and lost consciousness. Although she regained consciousness within one minute, she experienced lightheadedness for almost half an hour. She has experienced on-and-off dizziness for the past 2 weeks whenever she tries to stand. She has a history of type 2 diabetes mellitus, hypertension, hypercholesterolemia, and chronic kidney disease secondary to polycystic kidneys. Her medications include aspirin, bisoprolol, doxazosin, erythropoietin, insulin, rosuvastatin, and calcium and vitamin D supplements. She has a blood pressure of 111/74 mm Hg while supine and 84/60 mm Hg on standing, the heart rate of 48/min, the respiratory rate of 14/min, and the temperature of 37.0°C (98.6°F). CT scan of the head is unremarkable. Electrocardiogram reveals a PR interval of 250 ms. What is the next best step in the management of this patient?

Question: Electrocardiogram reveals a PR interval of 250 ms. What is the next best step in the management of this patient?

Answer: Stop antihypertensive medicines


Context: A group of researchers wish to develop a clinical trial assessing the efficacy of a specific medication on the urinary excretion of amphetamines in intoxicated patients. They recruit 50 patients for the treatment arm and 50 patients for the control arm of the study. Demographics are fairly balanced between the two groups. The primary end points include (1) time to recovery of mental status, (2) baseline heart rate, (3) urinary pH, and (4) specific gravity. Which medication should they use in order to achieve a statistically significant result positively favoring the intervention?

Question: Which medication should they use in order to achieve a statistically significant result positively favoring the intervention?

Answer: Ascorbic acid


Context:
A 32-year-old G6P1 woman presents to the obstetrician for a prenatal visit. She is 8 weeks pregnant. She has had 4 spontaneous abortions in the past, all during the first trimester. She tells you she is worried about having another miscarriage. She has been keeping to a strictly organic diet and takes a daily prenatal vitamin. She used to smoke a pack a day since she was 16 but quit after her first miscarriage. On a previous visit following fetal loss, the patient tested positive for VDRL and negative for FTA-ABS. Labs are drawn, as shown below:

Leukocyte count: 7,800/mm^3
Platelet count: 230,000/mm^3
Hemoglobin: 12.6 g/dL
Prothrombin time: 13 seconds
Activated partial thromboplastin time: 48 seconds
International normalized ratio: 1.2

Which of the following is the best next step in management?

Question:
Labs are drawn, as shown below:

Leukocyte count: 7,800/mm^3
Platelet count: 230,000/mm^3
Hemoglobin: 12.6 g/dL
Prothrombin time: 13 seconds
Activated partial thromboplastin time: 48 seconds
International normalized ratio: 1.2

Which of the following is the best next step in management?

Answer: Low molecular weight heparin


Context: A 28-year-old man presents to the clinic complaining of chronic joint pain and fatigue for the past 2 months. The patient states that he usually has pain in one of his joints that resolve but then seems to move to another joint. The patient notes no history of trauma but states that he has experienced some subjective fevers over that time. He works as a logger and notes that he’s heard that people have also had these symptoms in the past, but that he does not anyone who is currently experiencing them. What is the most likely etiologic agent of this patient’s disease?

Question: What is the most likely etiologic agent of this patient’s disease?

Answer: A spirochete


Context: A 34-year-old man presents to an outpatient clinic with chronic fatigue and bumps on his neck, right axilla, and groin. Upon questioning, he reveals he frequently visits Japan on business and is rather promiscuous on his business trips. He denies use of barrier protection. On examination, there is generalized lymphadenopathy. Routine lab work reveals abnormal lymphocytes on peripheral smear. The serum calcium is 12.2 mg/dL. Which of the following viruses is associated with this patient’s condition?

Question: Which of the following viruses is associated with this patient’s condition?

Answer: Human T-lymphotropic virus 1


Context: A 22-year-old primigravida is admitted to the obstetrics ward with leg swelling at 35 weeks gestation. She denies any other symptoms. Her pregnancy has been uneventful and she was compliant with the recommended prenatal care. Her vital signs were as follows: blood pressure, 168/95 mm Hg; heart rate, 86/min; respiratory rate, 16/min; and temperature, 36.7℃ (98℉). The fetal heart rate was 141/min. The physical examination was significant for 2+ pitting edema of the lower extremity. A dipstick test shows 1+ proteinuria. On reassessment 15 minutes later without administration of an antihypertensive, her blood pressure was 141/88 mm Hg, and the fetal heart rate was 147/min. A decision was made to observe the patient and continue the work-up without initiating antihypertensive therapy. Which of the following clinical features would make the suspected diagnosis into a more severe form?

Question: Which of the following clinical features would make the suspected diagnosis into a more severe form?

Answer: Blood pressure of 165/90 mm Hg reassessed 4 hours later


Context:
A 4-year-old girl is brought to the physician because of progressive intermittent pain and swelling in both knees and right ankle and wrist for 3 months. She has been taking acetaminophen and using ice packs, both of which relieved her symptoms. The affected joints feel ""stuck” and difficult to move when she wakes up in the morning, but she can move them freely after a few minutes. She has also occasional mild eye pain that resolves spontaneously. Five months ago she was diagnosed with upper respiratory tract infection that resolved without treatment. Vital signs are within normal limits. Examination shows that the affected joints are swollen, erythematous, and tender to touch. Slit-lamp examination shows an anterior chamber flare with signs of iris inflammation bilaterally. Laboratory studies show:
Hemoglobin 12.6 g/dl
Leukocyte count 8,000/mm3
Segmented neutrophils 76%
Eosinophils 1%
Lymphocytes 20%
Monocytes 3%
Platelet count 360,000/mm3
Erythrocyte sedimentation rate 36 mm/hr
Serum
Antinuclear antibodies 1:320
Rheumatoid factor negative
Which of the following is the most likely diagnosis?"

Question:
Laboratory studies show:
Hemoglobin 12.6 g/dl
Leukocyte count 8,000/mm3
Segmented neutrophils 76%
Eosinophils 1%
Lymphocytes 20%
Monocytes 3%
Platelet count 360,000/mm3
Erythrocyte sedimentation rate 36 mm/hr
Serum
Antinuclear antibodies 1:320
Rheumatoid factor negative
Which of the following is the most likely diagnosis?"

Answer: Oligoarticular juvenile idiopathic arthritis


Context: A 65-year-old male presents to your office complaining of worsening shortness of breath. He has experienced shortness of breath on and off for several years, but is noticing that it is increasingly more difficult. Upon examination, you note wheezing and cyanosis. You conduct pulmonary function tests, and find that the patient's FEV1/FVC ratio is markedly decreased. What is the most likely additional finding in this patient?

Question: What is the most likely additional finding in this patient?

Answer: Increased erythropoietin


Context: A 52-year-old man presents to the emergency department with nausea, palpitations, and lightheadedness after consuming a drink prepared from the leaves of yellow oleander (Thevetia peruviana). He had read somewhere that such a drink is healthy. As he liked the taste, he consumed 3 glasses of the drink before the symptoms developed. He also vomited twice. There is no past medical history suggestive of any significant medical condition. On physical examination, he is disoriented. The temperature is 36.5°C (97.8°F), the pulse is 140/min and irregular, the blood pressure is 94/58 mm Hg, and the respiratory rate is 14/min. Auscultation of the heart reveals an irregularly irregular heartbeat, while auscultation of the lungs does not reveal any significant abnormalities. The abdomen is soft and the pupillary reflexes are intact. An electrocardiogram shows peaked T waves. A botanist confirms that yellow oleander leaves contain cardiac glycosides. In addition to controlling the airway, breathing, and circulation with supportive therapy, which of the following medications is indicated?

Question: In addition to controlling the airway, breathing, and circulation with supportive therapy, which of the following medications is indicated?

Answer: Digoxin immune Fab