Context: A 79-year-old man is brought to the emergency department after he noted the abrupt onset of weakness accompanied by decreased sensation on his left side. His symptoms developed rapidly, peaked within 1 minute, and began to spontaneously resolve 10 minutes later. Upon arrival in the emergency room 40 minutes after the initial onset of symptoms, they had largely resolved. The patient has essential hypertension, type 2 diabetes mellitus, chronic obstructive pulmonary disease, and a 50 pack-year smoking history. He also had an ST-elevation myocardial infarction 3 years ago. His brain CT scan without contrast is reported as normal. Carotid duplex ultrasonography reveals 90% stenosis of the right internal carotid. His transthoracic echocardiogram does not reveal any intracardiac abnormalities. Which of the following interventions is most appropriate for this patient's condition?

Question: Which of the following interventions is most appropriate for this patient's condition?

Answer: Carotid stenting


Context: A 19-year-old woman comes to the physician because of a 1-month history of mild fatigue and weakness. Physical examination shows no abnormalities. Her hemoglobin concentration is 11 g/dL and mean corpuscular volume is 74 μm3. Hemoglobin electrophoresis shows 10% HbA2 (normal < 3.5%). Which of the following is the most likely diagnosis?

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

Answer: Beta thalassemia minor


Context:
A 59-year-old man comes to the emergency department because of worsening nausea and reduced urine output for the past 3 days. One week ago he had a 4-day episode of abdominal pain, vomiting, and watery, nonbloody diarrhea that began a day after he returned from a trip to Mexico. He has not been able to eat or drink much since then, but the symptoms resolved 3 days ago. He has a history of tension headaches, for which he takes ibuprofen about 10 times a month. He also has gastroesophageal reflux disease and benign prostatic hyperplasia. His daily medications include pantoprazole and alfuzosin. He appears pale. His temperature is 36.9°C (98.4°F), pulse is 120/min, and blood pressure is 90/60 mm Hg. Examination shows dry mucous membranes. The abdomen is soft without guarding or rebound. Laboratory studies show:
Hemoglobin 14.8 g/dL
Platelet count 250,000/mm3
Serum
Na+ 147 mEq/L
Cl- 102 mEq/L
K+ 4.7 mEq/L
HCO3- 20 mEq/L
Urea nitrogen 109 mg/dL
Glucose 80 mg/dL
Creatinine 3.1 mg/dL
Urinalysis shows no abnormalities. 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: Hypovolemia


Context: A 27-year-old woman presents to the emergency department because of muscle tightness and pain. She says that she has experienced increasing tightness and cramping of the muscles on the left side of her neck. She also says that she has trouble looking downwards because her “eyes are stuck.” She has a history of schizophrenia, which is being treated with haloperidol. Her temperature is 37.0°C (98.6°F), the pulse is 110/min, the respirations are 18/min, and the blood pressure is 115/71 mm Hg. Physical examination shows significant stiffness in her neck with muscle spasms. Her head is tilted severely to the left side, and her eyes are steady in upward gaze. Respiratory examination shows good air entry bilaterally with no wheezing. Which of the following medicines is the most appropriate next step in management?

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

Answer: Benztropine


Context: A 52-year-old man with stage IV melanoma comes to the physician with his wife for a routine follow-up examination. He was recently diagnosed with new bone and brain metastases despite receiving aggressive chemotherapy but has not disclosed this to his wife. He has given verbal consent to discuss his prognosis with his wife and asks the doctor to inform her of his condition because he does not wish to do so himself. She is tearful and has many questions about his condition. Which of the following would be the most appropriate statement by the physician to begin the interview with the patient's wife?

Question: Which of the following would be the most appropriate statement by the physician to begin the interview with the patient's wife?

Answer: """What is your understanding of your husband's current condition?"""


Context: A 4-week-old infant is brought to the physician by his mother because of blood-tinged stools for 3 days. He has also been passing whitish mucoid strings with the stools during this period. He was delivered at 38 weeks' gestation by lower segment transverse cesarean section because of a nonreassuring fetal heart rate. He was monitored in the intensive care unit for a day prior to being discharged. His 6-year-old brother was treated for viral gastroenteritis one week ago. The patient is exclusively breastfed. He is at the 50th percentile for height and 60th percentile for weight. He appears healthy and active. His vital signs are within normal limits. Examination shows a soft and nontender abdomen. The liver is palpated just below the right costal margin. The remainder of the examination shows no abnormalities. Test of the stool for occult blood is positive. A complete blood count and serum concentrations of electrolytes and creatinine are within the reference range. 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: Continue breastfeeding and advise mother to avoid dairy and soy products


Context: Two days after being admitted to the hospital because of severe peripartum vaginal bleeding during a home birth, a 40-year-old woman, gravida 3, para 3, has a 30-second generalized convulsive seizure followed by unconsciousness. Prior to the event she complained of acute onset of sweating and uncontrollable shivering. She was hemodynamically unstable and required several liters of intravenous fluids and 5 units of packed red blood cells in the intensive care unit. The patient's two prior pregnancies, at ages 33 and 35, were uncomplicated. She is otherwise healthy. Prior to admission, her only medication was a daily prenatal vitamin. Temperature is 37.5°C (99.5°F), pulse is 120/min, respirations are 18/min, blood pressure is 101/61 mm Hg. Pulse oximetry on room air shows an oxygen saturation of 96%. Examination shows very little milk expression from the breasts bilaterally. Finger-stick glucose level is 36 mg/dL. Which of the following is the most likely underlying cause of this patient's condition?

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

Answer: Pituitary ischemia


Context: A 26-year-old man presents with a 2-day history of worsening right lower leg pain. He states that he believes his right leg is swollen when compared to his left leg. Past medical history is significant for generalized anxiety disorder, managed effectively with psychotherapy. He smokes a pack of cigarettes daily but denies alcohol and illicit drug use. His father died of a pulmonary embolism at the age of 43. His vital signs include: temperature 36.7°C (98.0°F), blood pressure 126/74 mm Hg, heart rate 74/min, respiratory rate 14/min. On physical examination, the right lower leg is warmer than the left, and dorsiflexion of the right foot produces pain. Which of the following conditions is most likely responsible for this patient’s presentation?

Question: Which of the following conditions is most likely responsible for this patient’s presentation?

Answer: Factor V Leiden


Context: A 63-year-old woman presents to your outpatient clinic complaining of headaches, blurred vision, and fatigue. She has a blood pressure of 171/91 mm Hg and heart rate of 84/min. Physical examination is unremarkable. Her lab results include K+ of 3.1mEq/L and a serum pH of 7.51. Of the following, which is the most likely diagnosis for this patient?

Question: Of the following, which is the most likely diagnosis for this patient?

Answer: Primary hyperaldosteronism (Conn’s syndrome)


Context: A 62-year-old woman with type 2 diabetes mellitus is brought to the emergency room because of a 3-day history of fever and shaking chills. Her temperature is 39.4°C (103°F). Examination of the back shows right costovertebral angle tenderness. Analysis of the urine shows WBCs, WBC casts, and gram-negative rods. Ultrasound examination of the kidneys shows no signs of obstruction. Biopsy of the patient's kidney is most likely to show which of the following?

Question: Biopsy of the patient's kidney is most likely to show which of the following?

Answer: Polymorphonuclear leukocytes in tubules


Context: A 39-year-old woman is brought to the emergency department following a stab wound to the neck. Per the patient, she was walking her dog when she got robbed and was subsequently stabbed with a knife. Vitals are stable. Strength examination reveals 2/5 right-sided elbow flexion and extension, wrist extension, and finger motions. Babinski sign is upward-going on the right. There is decreased sensation to light touch and vibration on the patient's right side up to her shoulder. She also reports decreased sensation to pinprick and temperature on her left side, including her lower extremities, posterior forearm, and middle finger. The patient's right pupil is 2 mm smaller than the left with drooping of the right upper eyelid. Which of the following is the most likely cause of the patient’s presentation?

Question: Which of the following is the most likely cause of the patient’s presentation?

Answer: Hemisection injury


Context: A 32-year-old woman is brought to your office by her husband. The husband says that she had been acting strange lately. She has been forgetful, and she sometimes becomes angered for no reason, which is highly unusual for her. She has also been having random, uncontrollable movements, which are also new. On examination, she appears withdrawn and flat. On further questioning, she reveals that her father died at age 45 from a movement disorder. Which of the following is the pathological hallmark of the patient's condition?

Question: Which of the following is the pathological hallmark of the patient's condition?

Answer: Loss of neurons in the caudate nucleus and putamen


Context: A previously healthy 27-year-old man is brought to the emergency department 35 minutes after being involved in a high-speed motor vehicle collision in which he was an unrestrained passenger. He was ambulatory at the accident scene, with stable vital signs and no major external injuries except abrasions to both upper extremities. On arrival, he is alert and oriented. His temperature is 37.3°C (99.1°F), pulse is 88/min, respirations are 14/min, and blood pressure is 128/74 mm Hg. Abdominal examination shows ecchymosis over the upper abdomen, with tenderness to palpation over the left upper quadrant. There is no guarding or rigidity. Rectal examination is unremarkable. A CT scan of the abdomen with intravenous contrast shows a subcapsular splenic hematoma comprising 8% of the surface area, with no contrast extravasation and minimal blood in the peritoneal cavity. Which of the following is the next best step in management?

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

Answer: Hospitalization and frequent ultrasounds


Context: A 42-year-old man with chronic hepatitis C is admitted to the hospital because of jaundice and abdominal distention. He is diagnosed with decompensated liver cirrhosis, and treatment with diuretics is begun. Two days after admission, he develops abdominal pain and fever. Physical examination shows tense ascites and diffuse abdominal tenderness. Paracentesis yields cloudy fluid with elevated polymorphonuclear (PMN) leukocyte count. A drug with which of the following mechanisms is most appropriate for this patient's condition?

Question: A drug with which of the following mechanisms is most appropriate for this patient's condition?

Answer: Inhibition of bacterial peptidoglycan crosslinking


Context: A 27-year-old woman visits her family physician complaining of the recent onset of an unpleasant fish-like vaginal odor that has started to affect her sexual life. She was recently treated for traveler’s diarrhea after a trip to Thailand. External genitalia appear normal on pelvic examination, speculoscopy shows a gray, thin, homogenous, and malodorous vaginal discharge. Cervical mobilization is painless and no adnexal masses are identified. A sample of the vaginal discharge is taken for saline wet mount examination. Which of the following characteristics is most likely to be present in the microscopic evaluation of the sample?

Question: Which of the following characteristics is most likely to be present in the microscopic evaluation of the sample?

Answer: Clue cells on saline smear


Context: An office team is being observed by an outside agency at the request of management to make sure they are completing all their tasks appropriately. Several of the employees are nervous that they are being watched and take care to perform their jobs with extra care, more so than they would have done during a normal workday. What best describes this behavior?

Question: What best describes this behavior?

Answer: Hawthorne effect


Context: A previously healthy 2-year-old boy is brought to the emergency room by his mother because of persistent crying and refusal to move his right arm. The episode began 30 minutes ago after the mother lifted him up by the arms. He appears distressed and is inconsolable. On examination, his right arm is held close to his body in a flexed and pronated position. Which of the following is the most likely diagnosis?

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

Answer: Radial head subluxation


Context: A 26-year-old woman presents to a physician for genetic counseling, because she is worried about trying to have a child. Specifically, she had 2 siblings that died young from a lysosomal storage disorder and is afraid that her own children will have the same disorder. Her background is Ashkenazi Jewish, but she says that her husband's background is mixed European heritage. Her physician says that since her partner is not of Jewish background, their chance of having a child with Niemann-Pick disease is dramatically decreased. Which of the following genetic principles best explains why there is an increased prevalence of this disease in some populations?

Question: Which of the following genetic principles best explains why there is an increased prevalence of this disease in some populations?

Answer: Founder effect


Context: A newborn is delivered at term to a 38-year-old woman after an uncomplicated pregnancy and delivery. The newborn's blood pressure is 142/85 mm Hg. Examination shows clitoral enlargement and labioscrotal fusion. Serum studies show a sodium of 151 mg/dL and a potassium of 3.2 mg/dL. Karyotype analysis shows a 46, XX karyotype. The patient is most likely deficient in an enzyme that is normally responsible for which of the following reactions?

Question: The patient is most likely deficient in an enzyme that is normally responsible for which of the following reactions?

Answer: 11-deoxycorticosterone to corticosterone


Context: A 57-year-old man comes to the physician because of generalized malaise, yellowish discoloration of the eyes, and pruritus on the back of his hands that worsens when exposed to sunlight for the past several months. He has not seen a physician in 15 years. Physical examination shows scleral icterus and mild jaundice. There is a purpuric rash with several small vesicles and hyperpigmented lesions on the dorsum of both hands. The causal pathogen of this patient's underlying condition was most likely acquired in which of the following ways?

Question: The causal pathogen of this patient's underlying condition was most likely acquired in which of the following ways?

Answer: Needlestick injury


Context: A 23-year-old woman comes to the physician because of a 3-month history of pain during intercourse and vaginal dryness. The patient has also had intermittent hot flashes and fatigue during this time. Over the past year, her periods have become irregular. Her last menstrual period was over six months ago. She is sexually active with one partner and does not use protection or contraception. She has a history of acute lymphoblastic leukemia during childhood, which has remained in remission. Pelvic examination shows an atrophic cervix and vagina. A urinary pregnancy test is negative. A progestin challenge test is performed and shows no withdrawal bleeding. 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: Increased FSH to LH ratio


Context: A 56-year-old woman presents to a physician for evaluation of a lump in her left breast. She noticed the lump last week while taking a shower. She says that the lump seemed to be getting larger, which worried her. The lump is not painful. The medical history is unremarkable. She has smoked cigarettes for the last 30 years. On examination, bilateral small nodules are present that are non-tender and immobile. A mammography confirms the masses and fine needle aspiration cytology of the lesions reveals malignant cells arranged in a row of cells. What is the most likely diagnosis?

Question: What is the most likely diagnosis?

Answer: Invasive lobular carcinoma


Context: A 23-year-old woman is brought to the emergency department 30 minutes after being found unresponsive on the floor by her boyfriend. Paramedics found several empty pill bottles next to her on the floor. According to her boyfriend, she has a history of insomnia and generalized anxiety disorder and was recently diagnosed with depression. Her temperature is 36°C (96.8°F), pulse is 64/min, respirations are 10/min and shallow, and blood pressure is 112/75 mm Hg. On examination, she does not open her eyes, makes incomprehensible sounds, and extends her extremities when a painful stimulus is applied. Her pupils are 3 mm and reactive to light. The corneal reflex is normal and gag reflex is absent. There is diffuse hypotonia and decreased deep tendon reflexes. Cardiopulmonary examination shows no abnormalities. She is intubated for airway protection. Mechanical ventilation and an infusion of 0.9% saline are begun. Which of the following would most likely reverse this patient's condition?

Question: Which of the following would most likely reverse this patient's condition?

Answer: Flumazenil


Context: A 65-year-old woman with atrial fibrillation comes to the emergency department because of sudden-onset severe abdominal pain, nausea, and vomiting for the past 2 hours. She has smoked a pack of cigarettes daily for the past 25 years. Her pulse is 110/min and blood pressure is 141/98 mm Hg. Abdominal examination shows diffuse abdominal tenderness without guarding or rebound. A CT angiogram of the abdomen confirms an acute occlusion in the inferior mesenteric artery. Which of the following structures of the gastrointestinal tract is most likely to be affected in this patient?

Question: Which of the following structures of the gastrointestinal tract is most likely to be affected in this patient?

Answer: Rectosigmoid colon


Context: A 65-year old man comes to the emergency department because of altered mental status for 1 day. He has had headaches, severe nausea, vomiting, and diarrhea for 2 days. He has a history of hypertension, insomnia, and bipolar disorder. His medications include lisinopril, fluoxetine, atorvastatin, lithium, olanzapine, and alprazolam. His temperature is 37.2 °C (99.0 °F), pulse is 90/min, respirations are 22/min, and blood pressure is 102/68 mm Hg. He is somnolent and confused. His mucous membranes are dry. Neurological examination shows dysarthria, decreased muscle strength throughout, and a coarse tremor of the hands bilaterally. The remainder of the examination shows no abnormalities. In addition to IV hydration and electrolyte supplementation, which of the following is the next best step in management?

Question: In addition to IV hydration and electrolyte supplementation, which of the following is the next best step in management?

Answer: Hemodialysis


Context: A 42-year-old man presents with an intermittent low-to-high grade fever, night sweats, weight loss, fatigue, and exercise intolerance. The symptoms have been present for the last 6 months. The patient is a software developer. He smokes one-half pack of cigarettes daily and drinks alcohol occasionally. He denies intravenous drug use. There is no history of cardiovascular, respiratory, or gastrointestinal diseases or malignancies. There is no family history of cancer or cardiovascular diseases. The only condition he reports is a urinary bladder polyp, which was diagnosed and removed endoscopically almost 8 months ago. The patient does not currently take any medications. His blood pressure is 100/80 mm Hg, heart rate is 107/min, respiratory rate is 19/min, and temperature is 38.1°C (100.6°F). The patient is ill-looking and pale. There are several petechial conjunctival hemorrhages and macular lesions on both palms. The cardiac examination reveals heart enlargement to the left side and a holosystolic murmur best heard at the apex of the heart. There is also symmetric edema in both legs up to the knees. Which of the following organisms is most likely to be cultured from the patient’s blood?

Question: Which of the following organisms is most likely to be cultured from the patient’s blood?

Answer: Enterococcus faecalis


Context: A 1-year-old male is found to have high blood pressure on multiple visits to your office. On examination, the patient has normal genitalia. Further laboratory workup reveals low serum aldosterone and high serum testosterone. Which of the following is most likely to be elevated in this patient?

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

Answer: 11-deoxycorticosterone


Context: A 2-hours-old neonate is found to have bluish discoloration throughout his body, including lips and tongue. The boy was born at 39 weeks gestation via spontaneous vaginal delivery with no prenatal care. Maternal history is positive for type 2 diabetes mellitus for 11 years. On physical examination, his blood pressure is 55/33 mm Hg, his heart rate is 150/min, respiratory rate is 45/min, temperature of 37°C (98.6°F), and oxygen saturation is 84% on room air. Appropriate measures are taken. Auscultation of the chest reveals a single second heart sound without murmurs. Chest X-ray is shown in the exhibit. Which of the following is the most likely diagnosis?

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

Answer: Transposition of great vessels


Context: A 45-year-old woman comes to the physician for a 3-week history of intermittent episodes of dizziness. The episodes last for hours at a time and are characterized by the sensation that the room is spinning. The patient also reports that she has started using her cell phone with her left ear because she hears better on that side. She has experienced intermittent ringing and fullness in her right ear. She has no history of serious medical conditions. She does not smoke or drink alcohol. She takes no medications. Her temperature is 37.1°C (98.8°F) pulse is 76/min respirations are 18/min, and blood pressure is 130/76 mm Hg. Cardiopulmonary examination shows no abnormalities. There is horizontal nystagmus to the right. Motor strength is 5/5 in all extremities, and sensory examination shows no abnormalities. Finger-to-nose and heel-to-shin testing are normal bilaterally. Weber test shows lateralization to the left ear. The Rinne test is positive bilaterally. Which of the following is the most likely cause of this patient's symptoms?

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

Answer: Reduced resorption of endolymph


Context: A 21-year-old ِAfrican American woman presents with difficulty breathing, chest pain, and a non-productive cough. She says she took some ibuprofen earlier but it did not improve her pain. Past medical history is significant for sickle cell disease. Medications include hydroxyurea, iron, vitamin B12, and an oral contraceptive pill. She says she received a blood transfusion 6 months ago to reduce her Hgb S below 30%. Her vital signs include: temperature 38.2°C (100.7°F), blood pressure 112/71 mm Hg, pulse 105/min, oxygen saturation 91% on room air. A chest radiograph is performed and is shown in the exhibit. Which of the following is best initial step in the management of this patient’s condition?

Question: Which of the following is best initial step in the management of this patient’s condition?

Answer: Antibiotics and supportive care


Context: A 44-year-old woman comes to the physician because of a 6-month history of fatigue, constipation, and a 7-kg (15.4-lb) weight gain. Menses occur irregularly in intervals of 40–50 days. Her pulse is 51/min, and blood pressure is 145/86 mm Hg. Examination shows conjunctival pallor and cool, dry skin. There is mild, nonpitting periorbital edema. Serum thyroid-stimulating hormone concentration is 8.1 μU/mL. Treatment with the appropriate pharmacotherapy is initiated. After several weeks of therapy with this drug, which of the following hormonal changes is expected?

Question: After several weeks of therapy with this drug, which of the following hormonal changes is expected?

Answer: Increased reverse T3


Context: A 19-year-old man presents to the emergency department after a motor vehicle accident. The patient reports left shoulder pain that worsens with deep inspiration. Medical history is significant for a recent diagnosis of infectious mononucleosis. His temperature is 99°F (37.2°C), blood pressure is 80/55 mmHg, pulse is 115/min, and respiratory rate is 22/min. On physical exam, there is abdominal guarding, abdominal tenderness in the left upper quadrant, and rebound tenderness. The patient’s mucous membranes are dry and skin turgor is reduced. Which of the following most likely represents the acute changes in renal plasma flow (RPF) and glomerular filtration rate (GFR) in this patient?

Question: Which of the following most likely represents the acute changes in renal plasma flow (RPF) and glomerular filtration rate (GFR) in this patient?

Answer: Decreased RPF and no change in GFR


Context: A 62-year-old man comes to the physician for decreased exercise tolerance. Over the past four months, he has noticed progressively worsening shortness of breath while walking his dog. He also becomes short of breath when lying in bed at night. His temperature is 36.4°C (97.5°F), pulse is 82/min, respirations are 19/min, and blood pressure is 155/53 mm Hg. Cardiac examination shows a high-pitch, decrescendo murmur that occurs immediately after S2 and is heard best along the left sternal border. There is an S3 gallop. Carotid pulses are strong. Which of the following is the most likely diagnosis?

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

Answer: Aortic valve regurgitation


Context: A 35-year-old man is brought to the trauma bay by ambulance after sustaining a gunshot wound to the right arm. The patient is in excruciating pain and states that he can’t move or feel his hand. The patient states that he has no other medical conditions. On exam, the patient’s temperature is 98.4°F (36.9°C), blood pressure is 140/86 mmHg, pulse is 112/min, and respirations are 14/min. The patient is alert and his Glasgow coma scale is 15. On exam, he has a single wound on his right forearm without continued bleeding. The patient has preserved motor and sensation in his right elbow; however, he is unable to extend his wrist or extend his fingers further. He is able to clench his hand, but this is limited by pain. On sensory exam, the patient has no sensation to the first dorsal web space but has preserved sensation on most of the volar surface. Which of the following is the most likely injured?

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

Answer: Radial nerve


Context: An 8-month-old infant is brought to the physician by his mother because of a 1-month history of progressive listlessness. His mother says, ""He used to crawl around, but now he can't even keep himself upright. He seems so weak!"" Pregnancy and delivery were uncomplicated. Examination shows hypotonia and an increased startle response. Genetic analysis show insertion of four bases (TATC) into exon 11. Further evaluation shows decreased activity of hexosaminidase A. Which of the following mutations best explains these findings?"

Question: Which of the following mutations best explains these findings?"

Answer: Frameshift


Context: A 66-year-old woman is brought to the emergency department 4 hours after falling and hitting her head while skiing. Initially, she refused treatment, but an hour ago she began to develop a severe headache, nausea, and right leg weakness. She has osteopenia. Her only medication is a daily multivitamin. She has no visual changes and is oriented to person, time, and place. Her temperature is 37.2°C (99°F), pulse is 72/min, respirations are 18/min and regular, and blood pressure is 128/75 mm Hg. Examination shows a 5-cm bruise on the left side of her skull. The pupils are equal, round, and reactive to light and accommodation. Muscle strength is 0/5 in her right knee and foot. Which of the following is the most likely cause of this patient's symptoms?

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

Answer: Subfalcine herniation


Context: A 38-year-old female presents to the emergency room with fevers, fatigue, and anorexia for over a month. Past medical history includes mild mitral valve prolapse. She underwent an uncomplicated tooth extraction approximately 6 weeks ago. Her vital signs include a temperature of 100.8 F, pulse of 83, blood pressure of 110/77, and SpO2 of 97% on room air. On exam, you note a grade III/VI holosystolic murmur at the apex radiating to the axilla as well as several red, painful nodules on her fingers. Which of the following is the next best course of action?

Question: Which of the following is the next best course of action?

Answer: Obtain blood cultures x3 sites over 24 hours and start antibiotics after culture results are available


Context: A 3-week-old male infant is brought to the physician for follow-up. He was delivered at 30 weeks' gestation via Cesarean section and was cyanotic at birth, requiring resuscitation and a neonatal intensive care unit hospitalization. His mother received no prenatal care; she has diabetes mellitus type II and hypertension. She was not tested for sexually transmitted infections during the pregnancy. The infant appears well. Ophthalmologic examination shows tortuous retinal vessels. There are well-demarcated areas of non-vascularized retina in the periphery. This patient's retinal findings are most likely a result of which of the following?

Question: This patient's retinal findings are most likely a result of which of the following?

Answer: Oxygen toxicity


Context:
A 65-year-old man presented to the hospital with a history of repeated falls, postural dizziness, progressive fatigue, generalized weakness, and a 13.6 kg (30 lb) weight loss over a duration of 6 months. He is a vegetarian. His family members complain of significant behavioral changes over the past year. The patient denies smoking, alcohol consumption, or illicit drug use. There is no significant family history of any illness. Initial examination reveals a pale, thin built man. He is irritable, paranoid, delusional, but denies any hallucinations. The blood pressure is 100/60 mm Hg, heart rate is 92/min, respiratory rate is 16/min, and the temperature is 36.1℃ (97℉). He has an unstable, wide-based ataxic gait. The anti-intrinsic factor antibodies test is positive. The laboratory test results are as follows:
Hb 6.1gm/dL
MCV 99 fL
Platelets 900,000/mm3
Total WBC count 3,000/mm3
Reticulocyte 0.8%
The peripheral blood smear is shown in the image below. What is the most likely cause of his condition?

Question: What is the most likely cause of his condition?

Answer: Pernicious anemia


Context: A 32-year-old man comes to the physician because of generalized fatigue for the past 4 months. He also has difficulty sleeping and concentrating. He says he does not enjoy his hobbies anymore and has stopped attending family events. Mental status examination shows psychomotor retardation and a flat affect along with some evidence of suicidal ideation. His speech is slow in rate and monotone in rhythm. Treatment with fluoxetine is initiated. One month later, he reports significant improvement in his motivation and mood but also delayed ejaculation and occasional anorgasmia. The physician decides to replace his current medication with another agent. It is most appropriate to switch the patient to which of the following drugs?

Question: It is most appropriate to switch the patient to which of the following drugs?

Answer: Bupropion


Context: A trauma 'huddle' is called. Morphine is administered for pain. Low-flow oxygen is begun. A traumatic diaphragmatic rupture is suspected. Infusion of 0.9% saline is begun. 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: CT of the chest, abdomen, and pelvis


Context: A 25-year-old woman comes to the physician because of headache and difficulty sleeping for the past 2 days. She states that she has had similar symptoms over the past several months and that they occur every month around the same time. The episodes are also frequently accompanied by decreased concentration, angry feelings, and cravings for sweet foods. She says that during these episodes she is unable to work efficiently, and often has many arguments with her colleagues and friends. Menses occur at regular 26-day intervals and last 5 days. Her last menstrual period started about 3 weeks ago. She has smoked one pack of cigarettes daily for the last 8 years. She takes no medications. She appears irritable. The patient is oriented to person, place, and time. Physical examination shows no abnormalities. Which of the following is the most appropriate treatment?

Question: Which of the following is the most appropriate treatment?

Answer: Fluoxetine


Context: A 3-year-old boy is brought to the pediatrician by his parents with a presentation of severe diarrhea, vomiting, and fever for the past 2 days. The child is enrolled at a daycare where several other children have had similar symptoms in the past week. On physical exam, the child is noted to have dry mucous membranes. His temperature is 102°F (39°C). Questions regarding previous medical history reveal that the child’s parents pursued vaccine exemption to opt out of most routine vaccinations for their child. The RNA virus that is most likely causing this child’s condition has which of the following structural features?

Question: The RNA virus that is most likely causing this child’s condition has which of the following structural features?

Answer: Double-stranded, icosahedral, non-enveloped


Context: A previously healthy 37-year-old man comes to the physician for the evaluation of a 8-week history of intermittent burning epigastric pain. During this period, he has also felt bloated and uncomfortable after meals. He has not had weight loss or a change in bowel habits. He has no personal or family history of serious illness. He takes no medications. He does not smoke. He drinks 1–3 beers per week. Vital signs are within normal limits. Abdominal examination shows mild epigastric tenderness on palpation without guarding or rebound tenderness. Bowel sounds are normal. The remainder of the examination shows no abnormalities. 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: Urea breath test


Context: A 24-year-old woman comes to her primary care physician because she has not had a menstrual period for 6 months. She is a competitive runner and has been training heavily for the past year in preparation for upcoming races. She has no family or personal history of serious illness. She has not been sexually active for the past 9 months. Her temperature is 36.9°C (98.4° F), pulse is 51/min, respirations are 12/min, and blood pressure is 106/67 mm Hg. Her BMI is 18.1 kg/m2. Which of the following is the most likely cause of her amenorrhea?

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

Answer: Decreased frequency of GnRH release from the hypothalamus


Context:
A 76-year-old hypertensive man who used to smoke 20 cigarettes a day for 40 years but quit 5 years ago presents to his family physician with a painless ulcer on the sole of his left foot, located at the base of his 1st toe. He has a history of pain in his left leg that awakens him at night and is relieved by dangling his foot off the side of the bed. His wife discovered the ulcer last week while doing his usual monthly toenail trimming. On physical exam, palpation of the patient’s pulses reveals the following:
Right foot
Femoral 4+
Popliteal 3+
Dorsalis Pedis 2+
Posterior Tibial 1+
Left foot
Femoral 4+
Popliteal 2+
Dorsalis Pedis 0
Posterior Tibial 0
Pulse detection by Doppler ultrasound revealed decreased flow in the left posterior tibial artery, but no flow could be detected in the dorsalis pedis. What is the most likely principal cause of this patient’s ulcer?

Question: What is the most likely principal cause of this patient’s ulcer?

Answer: A narrowing of the superficial femoral artery


Context: A 72-year-old woman comes to the physician because she is seeing things that she knows are not there. Sometimes she sees a dog in her kitchen and at other times she sees a stranger in her garden, both of which no one else can see. She also reports a lack of motivation to do daily tasks for the past week. Three years ago, she was diagnosed with Parkinson disease and was started on levodopa and carbidopa. Her younger brother has schizophrenia. The patient also takes levothyroxine for hypothyroidism. She used to drink a bottle of wine every day, but she stopped drinking alcohol 2 months ago. Neurologic examination shows a mild resting tremor of the hands and bradykinesia. Her thought process is organized and logical. Which of the following is the most likely underlying cause of this patient's symptoms?

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

Answer: Adverse effect of medication


Context:
A 45-year-old man presents to the emergency department for worsening shortness of breath with exertion, mild chest pain, and lower extremity swelling. The patient reports increasing his alcohol intake and has been consuming a diet rich in salt over the past few days. Physical examination is significant for bilateral crackles in the lung bases, jugular venous distension, and pitting edema up to the knees. An electrocardiogram is unremarkable. He is admitted to the cardiac step-down unit. In the unit, he is started on his home anti-hypertensive medications, intravenous furosemide every 6 hours, and prophylactic enoxaparin. His initial labs on the day of admission are remarkable for the following:

Hemoglobin: 12 g/dL
Hematocrit: 37%
Leukocyte count: 8,500 /mm^3 with normal differential
Platelet count: 150,000 /mm^3

Serum:
Na+: 138 mEq/L
Cl-: 102 mEq/L
K+: 4.1 mEq/L
HCO3-: 25 mEq/L

On hospital day 5, routine laboratory testing is demonstrated below:

Hemoglobin: 12.5 g/dL
Hematocrit: 38%
Leukocyte count: 8,550 /mm^3 with normal differential
Platelet count: 60,000 /mm^3

Serum:
Na+: 140 mEq/L
Cl-: 100 mEq/L
K+: 3.9 mEq/L
HCO3-: 24 mEq/L

Physical examination is unremarkable for any bleeding and the patient denies any lower extremity pain. There is an erythematous and necrotic skin lesion in the left abdomen.

Which of the following best explains this patient’s current presentation?

Question: Which of the following best explains this patient’s current presentation?

Answer: Antibodies to heparin-platelet factor 4 complex


Context:
An otherwise healthy 42-year-old man undergoes routine investigations prior to blood donation. His complete blood count is shown:
Hemoglobin 9.3 g/dL
Mean corpuscular volume (MCV) 71 μm3
Mean corpuscular hemoglobin (MCH) 21 pg/cell
White blood cell count 8,200/mm3
Platelet count 317,000/mm3
Iron studies are shown:
Serum iron 210 μg/dL
Serum ferritin 310 ng/mL
Total iron binding capacity (TIBC) 290 μg/dL
Transferrin saturation 78%
He occasionally drinks alcohol and denies smoking or use of illicit drugs. There is a family history of anemia including his brother and maternal uncle. Examination shows conjunctival pallor, but is otherwise unremarkable. Which of the following is the most likely diagnosis?

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

Answer: Sideroblastic anemia


Context: A 7-year-old girl is brought by her parents to her pediatrician’s office for a persistent cough observed over the past month. She was diagnosed with cystic fibrosis 2 years ago and his been receiving chest physiotherapy regularly and the flu vaccine yearly. Her parents tell the pediatrician that their daughter has been coughing day and night for the past month, and produces thick, purulent, foul-smelling sputum. They are concerned because this is the first time such an episode has occurred. She has not had a fever, chills or any other flu-like symptoms. On examination, her blood pressure is 100/60 mm Hg, the pulse is 82/min, and the respiratory rate is 16/min. Breath sounds are reduced over the lower lung fields along with a presence of expiratory wheezing. Her sputum culture comes back positive for an aerobic, non-lactose fermenting, oxidase-positive, gram-negative bacillus. Which of the following prophylactic regimes should be considered after treating this patient for her current symptoms?

Question: Which of the following prophylactic regimes should be considered after treating this patient for her current symptoms?

Answer: Inhaled tobramycin


Context:
A 22-year-old man presents with lower limb weakness for the past 2 days. The patient says that the weakness started in both his feet, manifesting as difficulty walking, but it has progressed to where he cannot move his legs completely and has become bedbound. He also has experienced a recent history of numbness and tingling sensations in both his feet. He denies any recent history of fever, backache, urinary or bowel incontinence, trauma, shortness of breath, or diplopia. His past medical history is remarkable for a viral flu-like illness 2 weeks ago. The patient is afebrile, and his vital signs are within normal limits. On physical examination, muscle strength in both lower limbs is 1/5. The muscle strength in the upper limbs is ⅘ bilaterally. Sensation to pinprick is decreased in both lower limbs in a stocking distribution. The sensation is intact in the upper limbs bilaterally. Knee and ankle reflexes are absent bilaterally. The laboratory findings are significant for the following:
Hemoglobin 14.2 g/dL
White blood cell count  8,250/mm3
Platelet count 258,000/mm3
BUN 14 mg/dL
Creatinine  0.9 mg/dL
Serum sodium 144 mEq/L
Serum potassium 3.9 mEq/L
Which of the following tests would most likely confirm the diagnosis in this patient?

Question:
The laboratory findings are significant for the following:
Hemoglobin 14.2 g/dL
White blood cell count  8,250/mm3
Platelet count 258,000/mm3
BUN 14 mg/dL
Creatinine  0.9 mg/dL
Serum sodium 144 mEq/L
Serum potassium 3.9 mEq/L
Which of the following tests would most likely confirm the diagnosis in this patient?

Answer: Nerve conduction studies


Context: An 11-year-old girl presents to the emergency department with a 12-hour history of severe abdominal pain. She says that the pain started near the middle of her abdomen and moved to the right lower quadrant after about 10 hours. Several hours after the pain started she also started experiencing nausea and loss of appetite. On presentation, her temperature is 102.5°F (39.2°C), blood pressure is 115/74 mmHg, pulse is 102/min, and respirations are 21/min. Physical exam reveals rebound tenderness in the right lower quadrant. Raising the patient's right leg with the knee flexed significantly increases the pain. Which of the following is the most common cause of this patient's symptoms in children?

Question: Which of the following is the most common cause of this patient's symptoms in children?

Answer: Lymphoid hyperplasia


Context: A 40-year-old female presents to her gynecologist with dysmenorrhea, menorrhagia, and pelvic pain. The patient is not taking any medication and has no evidence of fever. Transvaginal sonogram reveals an enlarged, soft, and tender uterus, and uterine biopsy shows normal-appearing endometrial glands within the myometrium. 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: Adenomyosis


Context: A 10-month-old girl is brought to the physician because of a 4-day history of irritability and a rash. Her temperature is 37.7°C (99.9°F). Examination of the skin shows flaccid, transparent blisters and brown crusts on her chest and upper extremities. Application of a shear force to normal skin causes sloughing. Which of the following is the most likely underlying cause of this patient's condition?

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

Answer: Exfoliative toxin A release


Context: A 49-year-old man is referred to a cardiologist by his primary care provider (PCP) for a new heart murmur. He otherwise feels well and has no complaints. He had not seen a doctor in the last 15 years but finally went to his PCP for a check-up at the urging of his girlfriend. His past medical history is notable for gastroesophageal reflux disease, hypertension, and hepatitis B. He takes omeprazole and lisinopril. He has a prior history of intravenous drug abuse and a 50-pack-year smoking history. He has had many prior sexual partners and uses protection intermittently. He reports that he may have had a sore on his penis many years ago, but it went away without treatment. His temperature is 99°F (37.2°C), blood pressure is 141/91 mmHg, pulse is 89/min, and respirations are 18/min. On exam, S1 is normal and S2 has a tambour-like quality. There is a visible and palpable pulsation in the suprasternal notch and a diastolic decrescendo murmur over the right upper sternal border. A chest radiograph demonstrates calcification of the aortic root. Which of the following is the most likely cause of this patient's condition?

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

Answer: Vasa vasorum destruction


Context: A 22-year-old woman, gravida 2, para 1, at 41 weeks' gestation is admitted to the hospital in active labor. Pregnancy has been uncomplicated. At the beginning of the second stage of labor, the cervix is 100% effaced and 10 cm dilated; the vertex is at -1 station. The fetal heart rate is reactive with no decelerations. As she pushes, it is noted that the fetal heart rate decreases, as seen on cardiotocography (CTG). Which of the following is the most likely cause of this finding?

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

Answer: Fetal head compression


Context: A 3400-g (7-lb 8-oz) female newborn is delivered at term to a 28-year-old primigravid woman. Apgar scores are 7 and 8 at 1 and 5 minutes, respectively. Vital signs are within normal limits. Examination shows swelling of bilateral upper and lower extremities and low-set ears. The posterior hair line is low and the chest appears broad. There are skin folds running down the sides of the neck to the shoulders. A grade 2/6 systolic ejection murmur and systolic click is heard at the apex. Which of the following is the most likely cause of this patient's swelling?

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

Answer: Dysfunctional lymphatic system


Context: A 7-year-old boy is brought to the physician with a 2-day history of fever, chills, malaise, and a sore throat. He has otherwise been healthy and development is normal for his age. He takes no medications. His immunizations are up-to-date. His temperature is 38.4°C (101.4°F), pulse is 84/min, respirations are 16/min, and blood pressure is 121/71 mm Hg. Pulse oximetry shows an oxygen saturation of 100% on room air. Examination shows discrete 1–2-mm papulovesicular lesions on the posterior oropharynx and general erythema of the tonsils bilaterally. Which of the following conditions is most likely associated with the cause of this patient's findings?

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

Answer: Hand, foot, and mouth disease


Context: A 45-year-old obese woman presents to the office complaining of intermittent chest pain for the past 3 days. She states that the pain worsens when she lays down and after she eats her meals. She thinks that she has experienced similar pain before but does not remember it lasting this long. She also complains of a bitter taste in her mouth but is otherwise in no apparent distress. She has a history of asthma, a partial hysterectomy 4 years ago, and hypothyroidism that was diagnosed 7 years ago. She admits to drinking 5–6 cans of beer on weekend nights. Her blood pressure is 130/90 mm Hg, and her heart rate is 105/min. An ECG is performed that shows no abnormal findings. Which of the following is the most likely cause of her pain?

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

Answer: Decreased lower esophageal sphincter tone


Context: A 42-year-old man presents with palpitations, 2 episodes of vomiting, and difficulty breathing for the past hour. He says he consumed multiple shots of vodka at a party 3 hours ago but denies any recent drug use. The patient denies any similar symptoms in the past. Past medical history is significant for type 2 diabetes mellitus diagnosed 2 months ago, managed with a single drug that has precipitated some hypoglycemic episodes, and hypothyroidism diagnosed 2 years ago, well-controlled medically. The patient is a software engineer by profession. He reports a 25-pack-year smoking history and currently smokes 1 pack a day. He drinks alcohol occasionally but denies any drug use. His blood pressure is 100/60 mm Hg, pulse is 110/min, and respiratory rate is 25/min. On physical examination, the patient appears flushed and diaphoretic. An ECG shows sinus tachycardia. Which of the following medications is this patient most likely taking to explain his symptoms?

Question: Which of the following medications is this patient most likely taking to explain his symptoms?

Answer: Tolbutamide


Context: A 9-year-old girl is brought to the physician by her father because of multiple episodes of staring and facial grimacing that have occurred over the past 3 weeks. There are no precipitating factors for these episodes and they last for several minutes. She does not respond to her family members during these episodes. One week ago, her brother witnessed an episode in which she woke up while sleeping, stared, and made hand gestures. She does not remember any of these episodes but does recall having a vague muddy taste in her mouth prior to the onset of these symptoms. After the episode, she feels lethargic and is confused. Physical and neurologic examinations show no abnormalities. Which of the following is the most likely diagnosis?

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

Answer: Complex partial seizure


Context: A 26-year-old man with a history of alcoholism presents to the emergency department with nausea, vomiting, and right upper quadrant pain. Serum studies show AST and ALT levels >5000 U/L. A suicide note is found in the patient's pocket. The most appropriate initial treatment for this patient has which of the following mechanisms of action?

Question: The most appropriate initial treatment for this patient has which of the following mechanisms of action?

Answer: Glutathione substitute


Context: A 45-year-old African American male presents to his primary care physician complaining of difficulty swallowing that was initially limited to solids but has now progressed to liquids. Biopsy of the esophagus reveals dysplastic cells, but does not show evidence of glands or increased mucin. Which of the following patient behaviors most contributed to his condition?

Question: Which of the following patient behaviors most contributed to his condition?

Answer: Smoking


Context: A 7-year-old boy is being evaluated in pediatric cardiology clinic. He appears grossly normal, but suddenly becomes tachypneic and cyanotic when his mom takes a toy away from him. These symptoms resolve somewhat when he drops into a squatting position. Transthoracic echocardiography reveals pulmonic stenosis, a ventricular septal defect, right ventricular hypertrophy, and an overriding aorta. Which of the following best predicts the degree of cyanosis and other hypoxemic symptoms in this patient?

Question: Which of the following best predicts the degree of cyanosis and other hypoxemic symptoms in this patient?

Answer: Degree of pulmonic stenosis


Context: A 72-year-old man presents to his primary care provider at an outpatient clinic for ongoing management of his chronic hypertension. His past medical history is significant for diabetes and osteoarthritis though neither are currently being treated with medication. At this visit, his blood pressure is found to be 154/113 mmHg so he is started on lisinopril. After leaving the physician's office, he visits his local pharmacy and fills the prescription for lisinopril before going home. If this patient is insured by medicare with a prescription drug benefit provided by a private company through medicare, which of the following components of medicare are being used during this visit?

Question: If this patient is insured by medicare with a prescription drug benefit provided by a private company through medicare, which of the following components of medicare are being used during this visit?

Answer: Parts B and D


Context: A 16-year-old boy presents to the emergency room with severe right shoulder pain following a painful overhead swing during a competitive volleyball match. On physical examination, the patient has limited active range of motion of the right shoulder and significant pain with passive motion. Suspecting a rotator cuff injury, the physician obtains an MRI, which indicates a minor tear in the tendon of the rotator cuff muscle that is innervated by the axillary nerve. Which of the following muscles was affected?

Question: Which of the following muscles was affected?

Answer: Teres minor


Context: A rheumatologist is interested in studying the association between osteoporosis and the risk of sustaining a distal radius fracture. To explore this association, she develops a retrospective study design in which she identifies patients in a large institutional database over the age of 55 with and without osteoporosis, then follows them over a 10-year period to identify cases of distal radius fracture. She matches patients on age, sex, and body mass index to control for known confounding. After completing the study, she finds that patients with osteoporosis were at an increased risk of developing distal radius fractures. Which of the following study designs did this investigator use in this case?

Question: Which of the following study designs did this investigator use in this case?

Answer: Cohort study


Context: A 25-year-old female with no significant past medical history presents to her primary care physician with several weeks of increased fatigue and decreased exercise tolerance. On physical exam, her skin and conjunctiva appear pale. The physician suspects some form of anemia and orders a complete blood panel, which is remarkable for hemoglobin 11.7 g/dl, MCV 79 fL, MCHC 38% (normal 31.1-34%), and reticulocyte index 3.6%. Peripheral blood smear shows red blood cells with a lack of central pallor. This patient would most likely develop which of the following conditions?

Question: This patient would most likely develop which of the following conditions?

Answer: Gallstones


Context: A 62-year-old man comes to his primary care physician with a 3-month history of insomnia and severe work anxiety. He says that he is unable to retire because he has no financial resources; however, the stress level at his work has been causing him to have worsening performance and he is afraid of being fired. He thinks that he would be able to resume work normally if he was able to decrease his level of anxiety. His physician prescribes him a trial 1-month regimen of benzodiazepine therapy and schedules a follow-up appointment to see whether this treatment has been effective. Three weeks later, the patient's wife calls and says "My husband was fired from work and it's your fault for prescribing that medication! I know he must have been taking too much of that drug. Don't you know that he had a horrible problem with drug abuse in his 30s?" Which of the following is the most appropriate first action for the physician to take?

Question: Which of the following is the most appropriate first action for the physician to take?

Answer: Contact the patient directly to discuss the situation


Context:
A 53-year-old woman presents to a physician for a regular check-up. She has no complaints, but notes that she has been anxious and easily irritable for no particular reason over the past year. Six months ago, she was diagnosed with grade I arterial hypertension and prescribed lifestyle modification and weight loss to control her blood pressure. She currently takes aspirin (81 mg) and rosuvastatin (10 mg) daily. The vital signs are as follows: blood pressure 145/80 mm Hg, heart rate 81/min, respiratory rate 14/min, and temperature 36.6℃ (97.9℉). She weighs 91 kg (213.8 lb), the height is 167 cm (5.5 ft), and the BMI is 32.6 kg/m2. The physical examination is unremarkable. Blood testing was performed, and the results are shown below.
Plasma glucose 109.9 mg/dL (6.1 mmol/L)
Plasma triglycerides  185.8 mg/dL (2.1 mmol/L)
Na+ 141 mEq/L
K+ 4.2 mEq/L
The patient was prescribed atenolol. If the medication alone affects the patient’s measurements, which laboratory finding would you expect to note several weeks after the treatment is initiated?

Question: If the medication alone affects the patient’s measurements, which laboratory finding would you expect to note several weeks after the treatment is initiated?

Answer: Na+ 137 mEq/L


Context: A 43-year-old woman presents to her primary care physician with complaints of mild shortness of breath and right-sided chest pain for three days. She reports that lately she has had a nagging nonproductive cough and low-grade fevers. On examination, her vital signs are: temperature 99.1 deg F (37.3 deg C), blood pressure is 115/70 mmHg, pulse is 91/min, respirations are 17/min, and oxygen saturation 97% on room air. She is well-appearing, with normal work of breathing, and no leg swelling. She is otherwise healthy, with no prior medical or surgical history, currently taking no medications. The attending has a low suspicion for the most concerning diagnosis and would like to exclude it with a very sensitive though non-specific test. Which of the following should this physician order?

Question: Which of the following should this physician order?

Answer: Order a D-dimer


Context: A 29-year-old GP10 woman at 24 weeks estimated gestational age presents for follow-up. Six weeks ago, a complete blood count showed a microcytic hypochromic anemia for which she was prescribed iron sulfate tablets. A repeat complete blood count today shows no improvement in her hemoglobin level. Past medical history is significant for her being Rh-positive with an Rh-negative partner. She emigrated to the United States with her husband 7 years ago and did not have regular medical care in her country. An abdominal ultrasound shows findings consistent with hydrops fetalis. Which of the following is the most likely etiology of the condition of her fetus?

Question: Which of the following is the most likely etiology of the condition of her fetus?

Answer: Deletion of 4 alpha-globin genes


Context: A 17-year-old boy is brought to the physician because of a sore throat, nonproductive cough, and bloody urine for 3 days. He has had 2 similar episodes involving a sore throat and bloody urine over the past year. His sister has systemic lupus erythematosus. His temperature is 38.1°C (100.6°F). Serum studies show a urea nitrogen concentration of 8 mg/dL and a creatinine concentration of 1.4 mg/dL. Urinalysis shows acanthocytes and red blood cell casts. Renal ultrasonography shows no abnormalities. A renal biopsy is most likely to show which of the following findings?

Question: A renal biopsy is most likely to show which of the following findings?

Answer: IgA mesangial deposition


Context: A 34-year-old woman comes to the emergency department because of decreased appetite, nausea, vomiting, and episodic abdominal pain for the past two months. The pain is sharp, colicky, and lasts about an hour after meals. Her stools are light in appearance and difficult to flush. Physical examination shows tenderness in the right upper quadrant. Without treatment, this patient is at greatest risk for developing which of the following?

Question: Without treatment, this patient is at greatest risk for developing which of the following?

Answer: Low bone mineral density


Context: Laboratory studies, including serum vitamin B12 (cyanocobalamin), thyroxine (T4), and thyroid-stimulating hormone concentrations, are within normal limits. A lumbar puncture is performed. Cerebrospinal fluid (CSF) analysis is most likely to show which of the following?

Question: Cerebrospinal fluid (CSF) analysis is most likely to show which of the following?

Answer: Increased 14-3-3 protein concentration


Context: A 31-year-old woman presents to her primary care provider to discuss the results from a previous urine analysis. She has no new complaints and feels well. Past medical history is significant for systemic lupus erythematosus. She was diagnosed 5 years ago and takes hydroxychloroquine every day and prednisone when her condition flares. Her previous urine analysis shows elevated protein levels (4+) and blood (3+). The urine sediment contained red blood cells (6 RBCs/high-power field). The treating physician would like to perform a renal biopsy to rule out lupus nephritis. What type of hypersensitivity is suggestive of lupus nephritis?

Question: What type of hypersensitivity is suggestive of lupus nephritis?

Answer: Type III, mediated by IgG antibodies


Context:
A 10-year-old boy is brought to a pediatric clinic by his parents with pain and weakness in the lower extremities for the past 3 weeks. The patient’s mother says that he has been active until the weakness and pain started during his soccer practice sessions. He says he also experiences muscle cramps, especially at night. His mother adds that, recently, the patient constantly wakes up in the night to urinate and is noticeably thirsty most of the time. The patient denies any recent history of trauma to his legs. His vaccinations are up to date and his family history is unremarkable. His vital signs are within normal limits. Physical examination is unremarkable. Laboratory findings are shown below:
Laboratory test
Serum potassium 3.3 mEq/L
Serum magnesium  1.3 mEq/L
Serum chloride 101 mEq/L
pH 7.50
Pco2 38 mm Hg
HCO3- 20 mEq/L
Po2 88 mm Hg
Which of the following is the most likely diagnosis in this patient?

Question:
Laboratory findings are shown below:
Laboratory test
Serum potassium 3.3 mEq/L
Serum magnesium  1.3 mEq/L
Serum chloride 101 mEq/L
pH 7.50
Pco2 38 mm Hg
HCO3- 20 mEq/L
Po2 88 mm Hg
Which of the following is the most likely diagnosis in this patient?

Answer: Gitelman’s syndrome


Context: A 55-year-old man with alcoholic cirrhosis is admitted to the hospital for routine evaluation before liver transplantation. The physician asks the patient to stop eating 10 hours before surgery. Which of the following structures contributes directly to preventing fasting hypoglycemia by producing glucose in this patient?

Question: Which of the following structures contributes directly to preventing fasting hypoglycemia by producing glucose in this patient?

Answer: Intestine


Context: A crying 4-year-old child is brought to the emergency department with a red, swollen knee. He was in his usual state of health until yesterday, when he sustained a fall in the sandbox at the local park. His mother saw it happen; she says he was walking through the sandbox, fell gently onto his right knee, did not cry or seem alarmed, and returned to playing without a problem. However, later that night, his knee became red and swollen. It is now painful and difficult to move. The child’s medical history is notable for frequent bruising and prolonged bleeding after circumcision. On physical exam, his knee is erythematous, tender, and swollen, with a limited range of motion. Arthrocentesis aspirates frank blood from the joint. Which of the following single tests is most likely to be abnormal in this patient?

Question: Which of the following single tests is most likely to be abnormal in this patient?

Answer: Partial thromboplastin time (PTT)


Context: A 28-year-old male with a history of HIV infection is found to have a CD4+ T lymphocyte count of 68 cells per microliter. As a consequence of his HIV infection, this patient is at increased risk of malignancy due to which of the following?

Question: As a consequence of his HIV infection, this patient is at increased risk of malignancy due to which of the following?

Answer: Epstein-Barr Virus (EBV)


Context: A 75-year-old woman presents with sudden loss of vision. She says that she was reading when suddenly she was not able to see the print on half of the page. Her symptoms started 4 hours ago and are accompanied by a severe posterior headache. Vital signs reveal the following: blood pressure 119/76 mm Hg, pulse 89/min, SpO2 98% on room air. The patient was unable to recognize her niece when she arrived to see her. A noncontrast CT of the head shows no evidence of hemorrhagic stroke. What is the most likely diagnosis in this patient?

Question: What is the most likely diagnosis in this patient?

Answer: Posterior cerebral artery stroke


Context:
A 27-year-old man is brought to the emergency department 30 minutes after being shot in the abdomen during a violent altercation. His temperature is 36.5°C (97.7°F), pulse is 118/min and regular, and blood pressure is 88/65 mm Hg. Examination shows cool extremities. Abdominal examination shows a 2.5-cm entrance wound in the left upper quadrant at the midclavicular line, below the left costal margin. Focused ultrasound shows free fluid in the left upper quadrant. Which of the following sets of hemodynamic changes is most likely in this patient?
 $$$ Cardiac output (CO) %%% Pulmonary capillary wedge pressure (PCWP) %%% Systemic vascular resistance (SVR) %%% Central venous pressure (CVP) $$$

Question: $$$ Cardiac output (CO) %%% Pulmonary capillary wedge pressure (PCWP) %%% Systemic vascular resistance (SVR) %%% Central venous pressure (CVP) $$$


Context: A 30-year-old patient presents to clinic for pulmonary function testing. With body plethysmography, the patient's functional residual capacity is 3 L, tidal volume is 650 mL, expiratory reserve volume is 1.5 L, total lung capacity is 8 L, and dead space is 150 mL. Respiratory rate is 15 breaths per minute. What is the alveolar ventilation?

Question: What is the alveolar ventilation?

Answer: 7.5 L/min


Context: A 56-year-old man comes to the physician because of intermittent retrosternal chest pain. Physical examination shows no abnormalities. Endoscopy shows salmon pink mucosa extending 5 cm proximal to the gastroesophageal junction. Biopsy specimens from the distal esophagus show nonciliated columnar epithelium with numerous goblet cells. Which of the following is the most likely cause of this patient's condition?

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

Answer: Esophageal exposure to gastric acid


Context: A 23-year-old woman comes to the physician because of vaginal discharge for 3 days. She has been sexually active with three male partners over the past year and uses condoms inconsistently. Her only medication is an oral contraceptive. Physical exam shows thin grayish-white vaginal discharge. There is no erythema of the vaginal mucosa. The pH of the discharge is 5.9. Adding potassium hydroxide (KOH) to a mount containing vaginal discharge produces a fishy odor. Further evaluation of this patient's vaginal discharge is most likely to show which of the following findings?

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

Answer: Gram-variable rod


Context: A 39-year-old woman comes to the physician for a follow-up examination after a colonoscopy showed 42 hamartomatous polyps. The physical examination findings are shown in the photograph. Which of the following conditions is most likely to develop in this patient?

Question: Which of the following conditions is most likely to develop in this patient?

Answer: Pancreatic carcinoma


Context: A 60-year-old man who recently immigrated from South America schedules an appointment with a physician to complete his pre-employment health clearance form. According to company policy, a skin test for tuberculosis must be administered to all new employees. Thus, he received an intradermal injection of purified protein derivative (PPD) on his left forearm. After 48 hours, a 14-mm oval induration is noticed. The type of cells most likely present and responsible for the indurated area will have which of the following characteristic features?

Question: The type of cells most likely present and responsible for the indurated area will have which of the following characteristic features?

Answer: They need thymus for their maturation.


Context:
A 2-year-old girl is rushed to the emergency department by her parents following ingestion of unknown pills from an unmarked bottle she found at the park. The parents are not sure how many pills she ingested but say the child has been short of breath since then. Her respiratory rate is 50/min and pulse is 150/min. Examination shows the girl to be quite restless and agitated. No other findings are elicited. Laboratory testing shows:
Serum electrolytes
Sodium 142 mEq/L
Potassium 4.0 mEq/L
Chloride 105 mEq/L
Bicarbonate 14 mEq/L
   Serum pH 7.23
The girl most likely ingested which of the following drugs?

Question:
Laboratory testing shows:
Serum electrolytes
Sodium 142 mEq/L
Potassium 4.0 mEq/L
Chloride 105 mEq/L
Bicarbonate 14 mEq/L
   Serum pH 7.23
The girl most likely ingested which of the following drugs?

Answer: Acetaminophen


Context: An investigator is studying the genotypes of wingless fruit flies using full exome sequencing. Compared to wild-type winged fruit flies, the wingless fruit flies are found to have a point mutation in the gene encoding wing bud formation during embryogenesis. The point mutation in the gene causes the mRNA transcript to have a 'UUG' segment instead of an 'AUG' segment. Which of the following processes is most likely affected by this mutation?

Question: Which of the following processes is most likely affected by this mutation?

Answer: Binding of met-tRNA to 60S complex


Context:
A 7-year-old girl is brought to the physician because of a 1-month history of worsening fatigue, loss of appetite, and decreased energy. More recently, she has also had intermittent abdominal pain and nausea. She is at the 50th percentile for height and 15th percentile for weight. Her pulse is 119/min and blood pressure is 85/46 mm Hg. Physical examination shows darkened skin and bluish-black gums. The abdomen is soft and nontender. Serum studies show:
Sodium 133 mEq/L
Potassium 5.3 mEq/L
Bicarbonate 20 mEq/L
Urea nitrogen 16 mg/dL
Creatinine 0.8 mg/dL
Glucose 72 mg/dL
Which of the following is the most appropriate pharmacotherapy?"

Question:
Serum studies show:
Sodium 133 mEq/L
Potassium 5.3 mEq/L
Bicarbonate 20 mEq/L
Urea nitrogen 16 mg/dL
Creatinine 0.8 mg/dL
Glucose 72 mg/dL
Which of the following is the most appropriate pharmacotherapy?"

Answer: Glucocorticoids


Context: A 28-year-old woman comes to the physician because of an 8-hour history of painful leg cramping, a runny nose, and chills. She has also had diarrhea and abdominal pain. She appears irritable and yawns frequently. Her pulse is 115/min. Examination shows cool, damp skin with piloerection. The pupils are 7 mm in diameter and equal in size. Bowel sounds are hyperactive. Deep tendon reflexes are 3+ bilaterally. Withdrawal from which of the following substances is most likely the cause of this patient's symptoms?

Question: Withdrawal from which of the following substances is most likely the cause of this patient's symptoms?

Answer: Heroin


Context: A previously healthy 17-year-old boy is brought to the emergency department because of fever, nausea, and myalgia for the past day. His temperature is 39.5°C (103.1°F), pulse is 112/min, and blood pressure is 77/55 mm Hg. Physical examination shows scattered petechiae over the anterior chest and abdomen. Blood culture grows an organism on Thayer-Martin agar. Which of the following virulence factors of the causal organism is most likely responsible for the high mortality rate associated with it?

Question: Which of the following virulence factors of the causal organism is most likely responsible for the high mortality rate associated with it?

Answer: Lipooligosaccharide


Context:
A 47-year-old woman presents to the emergency department with ongoing dyspnea and confusion for 2 hours. She has a history of psychosis and alcohol abuse. She has smoked 1 pack per day for 25 years. She is agitated and confused. Her blood pressure is 165/95 mm Hg; pulse 110/min; respirations 35/min; and temperature, 36.7°C (98.1°F). The pulmonary examination shows tachypnea and mild generalized wheezing. Auscultation of the heart shows no abnormal sounds. The remainder of the physical examination shows no abnormalities. Laboratory studies show:
Serum
Na+ 138 mEq/L
CI- 100 mEq/L
Arterial blood gas analysis on room air
pH 7.37
pCO2 21 mm Hg
pO2 88 mm Hg
HCO3- 12 mEq/L
Which of the following best explains these findings?

Question:
Laboratory studies show:
Serum
Na+ 138 mEq/L
CI- 100 mEq/L
Arterial blood gas analysis on room air
pH 7.37
pCO2 21 mm Hg
pO2 88 mm Hg
HCO3- 12 mEq/L
Which of the following best explains these findings?

Answer: Salicylate intoxication


Context: An endocrine surgeon wants to evaluate the risk of multiple endocrine neoplasia (MEN) type 2 syndromes in patients who experienced surgical hypertension during pheochromocytoma resection. She conducts a case-control study that identifies patients who experienced surgical hypertension and subsequently compares them to the control group with regard to the number of patients with underlying MEN type 2 syndromes. The odds ratio of MEN type 2 syndromes in patients with surgical hypertension during pheochromocytoma removal was 3.4 (p < 0.01). The surgeon concludes that the risk of surgical hypertension during pheochromocytoma removal is 3.4 times greater in patients with MEN type 2 syndromes than in patients without MEN syndromes. This conclusion is best supported by which of the following assumptions?

Question: This conclusion is best supported by which of the following assumptions?

Answer: Surgical hypertension associated with pheochromocytoma is rare


Context: A 3-year-old boy presents to the pediatrics clinic for follow-up. He has a history of severe pyogenic infections since birth. Further workup revealed a condition caused by a defect in CD40 ligand expressed on helper T cells. This congenital immunodeficiency has resulted in an inability to class switch and a poor specific antibody response to immunizations. Which of the following best characterizes this patient's immunoglobulin profile?

Question: Which of the following best characterizes this patient's immunoglobulin profile?

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


Context:
A 25-year-old woman presents to her primary care clinic for a general checkup. She states she's been a bit more fatigued lately during finals season but is otherwise well. Her mother and sister have hypothyroidism. She denies fatigue, weight gain, cold intolerance, constipation, heavy or irregular menses, or changes in the quality of her hair, skin, or nails. Physical exam is unremarkable. Laboratory studies are ordered as seen below.

Hemoglobin: 14 g/dL
Hematocrit: 40%
Leukocyte count: 5,500/mm^3 with normal differential
Platelet count: 188,000/mm^3

Serum:
Na+: 139 mEq/L
Cl-: 102 mEq/L
K+: 4.4 mEq/L
HCO3-: 24 mEq/L
BUN: 20 mg/dL
Glucose: 99 mg/dL
Creatinine: 0.8 mg/dL
Ca2+: 10.2 mg/dL
Antithyroid peroxidase Ab: Positive
AST: 12 U/L
ALT: 10 U/L

Which of the following laboratory values is most likely in this patient?

Question:
Hemoglobin: 14 g/dL
Hematocrit: 40%
Leukocyte count: 5,500/mm^3 with normal differential
Platelet count: 188,000/mm^3

Serum:
Na+: 139 mEq/L
Cl-: 102 mEq/L
K+: 4.4 mEq/L
HCO3-: 24 mEq/L
BUN: 20 mg/dL
Glucose: 99 mg/dL
Creatinine: 0.8 mg/dL
Ca2+: 10.2 mg/dL
Antithyroid peroxidase Ab: Positive
AST: 12 U/L
ALT: 10 U/L

Which of the following laboratory values is most likely in this patient?

Answer: Normal TSH and normal T4


Context: A 69-year-old man presents to his dermatologist with an enlarging, scaly pink plaque on his face. It has been present for 5 weeks and is shown. Physical examination reveals a friable lesion that bleeds easily. Medical history is remarkable for type 1 diabetes mellitus complicated by end-stage kidney disease, which required kidney transplantation 5 years ago. The patient also reports a history of common viral warts but has not had any in several years. A skin biopsy of the lesion reveals full-thickness keratinocyte atypia with keratin pearls. Which of the following is a key risk factor for this patient's condition?

Question: Which of the following is a key risk factor for this patient's condition?

Answer: Immunosuppression


Context:
A 48-year-old man comes to the physician because of severe joint pain and swelling involving different joints for 3 months. He has also been having loose stools and episodes of epigastric pain for 6 months. He reports a 10-kg (22-lb) weight loss during this period. He has type 2 diabetes mellitus. He does not smoke or drink alcohol. His medications include insulin and metformin. His vital signs are within normal limits. Examination shows pale conjunctivae, angular cheilitis, and glossitis. Axillary and cervical lymphadenopathy is present. A grade 2/6 pansystolic murmur is heard best at the apex. The right knee is swollen and tender; range of motion is limited. The sacroiliac joints are tender. Test of the stool for occult blood is negative. Laboratory studies show:
Hemoglobin 9.2 g/dL
Mean corpuscular volume 90 μm3
Leukocyte count 4,800/mm3
Serum
Na+ 134 mEq/L
Cl- 96 mEq/L
K+ 3.3 mEq/L
Glucose 143 mg/dL
Creatinine 1.2 mg/dL
A small intestine biopsy shows periodic acid-Schiff-positive (PAS-positive) macrophages in the lamina propria. 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: Intravenous ceftriaxone


Context: A 6-year-old boy is brought to the pediatrician by his parents. He has been coughing extensively over the last 5 days, especially during the night. His mother is worried that he may have developed asthma, like his uncle, because he has been wheezing, too. The boy usually plays without supervision, and he likes to explore. He has choked a few times in the past. He was born at 38 weeks of gestation via a normal vaginal delivery. He has no known allergies. Considering the likely etiology, what is the best approach to manage the condition of this child?

Question: Considering the likely etiology, what is the best approach to manage the condition of this child?

Answer: Perform bronchoscopy


Context: A 30-year-old man comes to the physician for a follow-up examination 1 month after sustaining a chemical burn over the dorsum of his right hand and forearm. Physical examination shows hyperextension of the hand at the wrist. The skin over the dorsum of the wrist is tense and there is a thick, epithelialized scar. Range of motion of the right wrist is restricted. This patient's contracture is most likely due to activity of which of the following cells?

Question: This patient's contracture is most likely due to activity of which of the following cells?

Answer: Myofibroblasts


Context: A 60-year-old man comes to the physician because of persistent fatigue over the past ten months. His previous annual health maintenance examination showed no abnormalities. He appears pale. Physical examination shows numerous petechial lesions over the abdomen and marked splenomegaly. His serum hemoglobin concentration is 9.4 g/dL, leukocyte count is 4,100/mm3, and thrombocyte count is 110,000/mm3. A peripheral blood smear shows large white blood cells with centrally placed nuclei and multiple fine, radial cytoplasmic projections that stain positively for tartrate-resistant acid phosphatase (TRAP). Which of the following is the most likely characteristic of the medication used as first-line treatment for this patient's condition?

Question: Which of the following is the most likely characteristic of the medication used as first-line treatment for this patient's condition?

Answer: Resistant to breakdown by adenosine deaminase


Context: A 29-year-old G1P0 presents to her obstetrician for her first prenatal care visit at 12 weeks gestation by last menstrual period. She states that her breasts are very tender and swollen, and her exercise endurance has declined. She otherwise feels well. She is concerned about preterm birth, as she heard that certain cervical procedures increase the risk. The patient has a gynecologic history of loop electrosurgical excision procedure (LEEP) for cervical dysplasia several years ago and has had negative Pap smears since then. She also has mild intermittent asthma that is well controlled with occasional use of her albuterol inhaler. At this visit, this patient’s temperature is 98.6°F (37.0°C), pulse is 69/min, blood pressure is 119/61 mmHg, and respirations are 13/min. Cardiopulmonary exam is unremarkable, and the uterine fundus is just palpable at the pelvic brim. Pelvic exam reveals normal female external genitalia, a closed and slightly soft cervix, a 12-week-size uterus, and no adnexal masses. Which of the following is the best method for evaluating for possible cervical incompetence in this patient?

Question: Which of the following is the best method for evaluating for possible cervical incompetence in this patient?

Answer: Transvaginal ultrasound at 18 weeks gestation


Context: A 55-year-old man presents to his primary care physician for knee pain. The patient has had left knee pain, which has been steadily worsening for the past year. He states that ice and rest has led to minor improvement in his symptoms. He recently bumped his knee; however, he says that it has not altered his baseline pain when ambulating. The patient is a butcher and lives with his wife. His current medications include insulin, metformin, hydrochlorothiazide, and lisinopril. He is attending Alcoholics Anonymous with little success. Physical exam reveals a left knee that is mildly erythematous with some bruising. There is no pain upon palpation of the join or with passive range of motion. The patient exhibits a mildly antalgic gait. Which of the following is the best initial step in management?

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

Answer: Weight loss


Context:
A 66-year-old woman comes to the emergency department because of a 1-day history of severe abdominal pain, nausea, and vomiting. She has also had profuse watery diarrhea with streaks of blood for the past 5 days. She had a urinary tract infection 3 weeks ago and was treated with a 14-day course of ciprofloxacin. She appears in severe distress. Her temperature is 39.3°C (102.7°F), pulse is 110/min, and blood pressure is 100/60 mm Hg. Examination shows a distended abdomen, tenderness in the lower quadrants, and hypoactive bowel sounds; rebound tenderness and abdominal rigidity are absent. Cardiopulmonary examination shows no abnormalities. Test of the stool for occult blood is positive. Laboratory studies show:
Hemoglobin 10.2 g/dL
Leukocyte count 28,000/mm3
Serum
Na+ 133 mEq/L
K+ 3.3 mEq/L
Cl- 97 mEq/L
Glucose 98 mg/dL
Creatinine 1.3 mg/dL
Two wide bore needles are inserted and intravenous fluids are administered. An abdominal x-ray of the patient would be most likely to show which of the following?"

Question: An abdominal x-ray of the patient would be most likely to show which of the following?"

Answer: Dilation of the colon with loss of haustration


Context: A 49-year-old woman comes to the physician because of a 4-month history of fatigue and recurrent pain in both of her wrists and her fingers. During this time, she has also had stiffness of her joints for about 80 minutes after waking up in the morning. Examination shows swelling and tenderness of the wrists and metacarpophalangeal joints bilaterally. Her serum erythrocyte sedimentation rate is 42 mm/h and rheumatoid factor is positive. Treatment is begun with a drug that results in decreased synthesis of deoxythymidine monophosphate. This mechanism is most similar to the mechanism of action of which of the following drugs?

Question: This mechanism is most similar to the mechanism of action of which of the following drugs?

Answer: Trimethoprim


Context: A 73-year-old man presents to his primary care doctor with his son who reports that his father has been acting strangely. He has started staring into space throughout the day and has a limited attention span. He has been found talking to people who are not present and has gotten lost while driving twice. He has occasional urinary incontinence. His past medical history is notable for a stroke 5 years ago with residual right arm weakness, diabetes, hypertension, and hyperlipidemia. He takes aspirin, glyburide, metformin, lisinopril, hydrochlorothiazide, and atorvastatin. On examination, he is oriented to person and place but thinks the year is 1989. He is inattentive throughout the exam. He takes short steps while walking. His movements are grossly slowed. A brain biopsy in this patient would most likely reveal which of the following?

Question: A brain biopsy in this patient would most likely reveal which of the following?

Answer: Eosinophilic intracytoplasmic inclusions


Context: A 69-year-old man with aggressive metastatic cholangiocarcinoma presents after the second round of chemotherapy. He has suffered a great deal of pain from the metastasis to his spine, and he is experiencing side effects from the cytotoxic chemotherapy drugs. Imaging shows no change in the tumor mass and reveals the presence of several new metastatic lesions. The patient is not willing to undergo any more chemotherapy unless he gets something for pain that will “knock him out”. High-dose opioids would be effective, in his case, but carry a risk of bradypnea and sudden respiratory failure. 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: Give the high-dose opioids


Context:
A 34-year-old woman is brought to the emergency department by fire and rescue after an apparent suicide attempt. She reports ingesting several pills 6 hours prior to presentation but cannot recall what they were. No pills were found on the scene. She complains of severe malaise, ringing in her ears, and anxiety. Her past medical history is notable for bipolar disorder, generalized anxiety disorder, rheumatoid arthritis, obesity, and diabetes. She takes lithium, methotrexate, metformin, and glyburide. She has a reported history of benzodiazepine and prescription opioid abuse. Her temperature is 102.2°F (39°C), blood pressure is 135/85 mmHg, pulse is 110/min, and respirations are 26/min. On exam, she appears diaphoretic and pale. Results from an arterial blood gas are shown:

pH: 7.48
PaCO2: 32 mmHg
HCO3-: 23 mEq/L

This patient should be treated with which of the following?

Question:
Results from an arterial blood gas are shown:

pH: 7.48
PaCO2: 32 mmHg
HCO3-: 23 mEq/L

This patient should be treated with which of the following?

Answer: Sodium bicarbonate


Context: A 19-year-old woman is diagnosed with metastatic Ewing sarcoma. She has undergone multiple treatments without improvement. She decides to stop treatment and pursue only palliative care. She is of sound mind and has weighed the benefits and risks of this decision. The patient’s mother objects and insists that treatments be continued. What should be done?

Question: What should be done?

Answer: Halt treatments and begin palliative care.


Context: A 4-year-old girl is brought to the physician because of increasing swelling around her eyes and over both her feet for the past 4 days. During this period, she has had frothy light yellow urine. Her vital signs are within normal limits. Physical examination shows periorbital edema and 2+ pitting edema of the lower legs and ankles. A urinalysis of this patient is most likely to show which of the following findings?

Question: A urinalysis of this patient is most likely to show which of the following findings?

Answer: Fatty casts


Context: A 74-year-old woman is brought to the physician by her daughter for worsening memory for the past 1 month. She can no longer manage her bills and frequently forgets the names of her children. Her daughter is also concerned that her mother has a urinary tract infection because she has had increased urinary urgency and several episodes of urinary incontinence. Vital signs are within normal limits. Physical examination shows poor short-term memory recall and a slow gait with wide, short steps. Which of the following is most likely to improve this patient's condition?

Question: Which of the following is most likely to improve this patient's condition?

Answer: Cerebral shunt placement


Context:
A 42-year-old woman is brought to the emergency department because of a 5-day history of epigastric pain, fever, nausea, and malaise. Five weeks ago she had acute biliary pancreatitis and was treated with endoscopic retrograde cholangiopancreatography and subsequent cholecystectomy. Her maternal grandfather died of pancreatic cancer. She does not smoke. She drinks 1–2 beers daily. Her temperature is 38.7°C (101.7°F), respirations are 18/min, pulse is 120/min, and blood pressure is 100/70 mm Hg. Abdominal examination shows epigastric tenderness and three well-healed laparoscopy scars. The remainder of the examination shows no abnormalities. Laboratory studies show:
Hemoglobin 10 g/dL
Leukocyte count 15,800/mm3
Serum
Na+ 140 mEq/L
Cl− 103 mEq/L
K+ 4.5 mEq/L
HCO3- 25 mEq/L
Urea nitrogen 18 mg/dL
Creatinine 1.0 mg/dL
Alkaline phosphatase 70 U/L
Aspartate aminotransferase (AST, GOT) 22 U/L
Alanine aminotransferase (ALT, GPT) 19 U/L
γ-Glutamyltransferase (GGT) 55 U/L (N = 5–50)
Bilirubin 1 mg/dl
Glucose 105 mg/dL
Amylase 220 U/L
Lipase 365 U/L (N = 14–280)
Abdominal ultrasound shows a complex cystic fluid collection with irregular walls and septations in the pancreas. Which of the following is the most likely diagnosis?"

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

Answer: Pancreatic abscess


Context: A 38-year-old man is brought to the emergency department 35 minutes after an episode of loss of consciousness. He was having dinner with a client when his left arm suddenly became weak and numb. A few minutes later he became tense and his arms and legs began jerking violently, following which he lost consciousness. He has no recollection of this event. He works as a business consultant. He has a history of asthma and major depressive disorder. Current medication include an albuterol inhaler and doxepin. He increased the dose of doxepin one week ago because he felt the medication was not helping. He drinks two to three beers on the weekend. He admits to using cocaine 4–5 times per week. On arrival, he is alert and oriented to person, place, and time. His speech is slurred. His temperature is 37°C (98.6F), pulse is 96/min, and blood pressure is 155/90 mm Hg. The pupils are equal and reactive to light. Neurologic exam shows left facial droop. There is 3/5 strength in the left arm. Which of the following is the most likely underlying mechanism of this patient's symptoms?

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

Answer:
Vasospasm of cerebral vessels
"


Context: A 32-year-old man, otherwise healthy, presents with flank pain and severe nausea for the last 9 hours. He describes the pain as severe, intermittent, localized to the right flank, and radiates to the groin. His past medical history is significant for recurrent nephrolithiasis. The patient does not smoke and drinks alcohol socially. Today his temperature is 37.0°C (98.6°F), the pulse is 90/min, the respiratory rate is 25/min, and the oxygen saturation is 99% on room air. On physical examination, the patient is in pain and unable to lie still. The patient demonstrates severe costovertebral angle tenderness. The remainder of the exam is unremarkable. Non-contrast CT of the abdomen and pelvis reveals normal-sized kidneys with the presence of a single radiopaque stone lodged in the ureteropelvic junction and clusters of pyramidal medullary calcifications in both kidneys. Intravenous pyelography reveals multiple, small cysts measuring up to 0.3 cm in greatest dimension in medullary pyramids and papillae of both kidneys. Which of the following would you also most likely expect to see in this patient?

Question: Which of the following would you also most likely expect to see in this patient?

Answer: Hematuria


Context: A 37-year-old African-American man presents to his primary care provider with a history of fatigue and nausea that started about 6 months ago. His symptoms have slowly gotten worse and now he has trouble climbing the stairs to his 3rd floor apartment without resting. Past medical history is significant for poorly controlled HIV and a remote history of heroin addiction. Today his temperature is 36.9°C (98.4°F), the blood pressure is 118/72 mm Hg, and the pulse is 75/min. Physical examination reveals morbid obesity and 1+ pitting edema of both lower extremities. Urine dipstick reveals 2+ proteinuria. Urinalysis shows no abnormal findings. Which of the following is the most likely etiology of this patient condition?

Question: Which of the following is the most likely etiology of this patient condition?

Answer: Focal segmental glomerulosclerosis


Context: A 24-year-old woman presents with episodic shortness of breath, chest tightness, and wheezing. She has noticed an increased frequency of such episodes in the spring season. She also has a history of urticaria. She has smoked a half pack of cigarettes per day over the last 5 years. Her mother also has similar symptoms. The physical exam is within normal limits. Which of the following findings is characteristic of her condition?

Question: Which of the following findings is characteristic of her condition?

Answer: Decrease in forced expiratory volume in 1 second (FEV1) after methacholine


Context: A 28-year-old woman presents with increased facial hair growth. She says she noticed a marked growth and darkening of hair on her face and feels embarrassed. Past medical history is significant for asthma, well-controlled by medication, and epilepsy diagnosed 6 months ago, managed with phenytoin. Her other medications are albuterol, beclomethasone, a daily multivitamin, and a garlic supplement. The patient denies any smoking history, alcohol or recreational drug use. Family history is significant for asthma in her father. Review of systems is positive for occasional diplopia. Her pulse is 75/min, respiratory rate is 15 /min, and blood pressure is 110/76 mm Hg. Her body mass index (BMI) is 24 kg/m2. On physical examination, she appears healthy in no apparent distress. There are excessive facial hair growth and enlarged gums. The remainder of the examination is unremarkable. Which of the following medications is most likely responsible for this patient's symptoms?

Question: Which of the following medications is most likely responsible for this patient's symptoms?

Answer: Phenytoin


Context: A 14-year-old boy is brought to the physician by his parents for the evaluation of a skin rash for one day. The patient reports intense itching. He was born at 39 weeks' gestation and has a history of atopic dermatitis. He attends junior high school and went on a camping trip with his school the day before yesterday. His older brother has celiac disease. Examination shows erythematous papules and vesicles that are arranged in a linear pattern on the right forearm. Laboratory studies are within normal limits. Which of the following is the most likely underlying cause of this patient's symptoms?

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

Answer: Presensitized T cells