Context: A 23-year-old man is brought to the emergency department because of severe right shoulder pain and inability to move the shoulder for the past 30 minutes. The pain began after being tackled while playing football. He has nausea but has not vomited. He is in no apparent distress. Examination shows the right upper extremity externally rotated and slightly abducted. Palpation of the right shoulder joint shows tenderness and an empty glenoid fossa. The right humeral head is palpated below the coracoid process. The left upper extremity is unremarkable. The radial pulses are palpable bilaterally. 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: Test sensation of the lateral shoulder


Context: A 20-year-old man is found lying unconscious on the floor of his room by his roommate. The paramedics arrive at the site and find him unresponsive with cold, clammy extremities and constricted, non-reactive pupils. He smells of alcohol and his vital signs show the following: blood pressure 110/80 mm Hg, pulse 100/min, and respiratory rate 8/min. Intravenous access is established and dextrose is administered. The roommate suggests the possibility of drug abuse by the patient. He says he has seen the patient sniff a powdery substance, and he sees the patient inject himself often but has never confronted him about it. After the initial assessment, the patient is given medication and, within 5–10 minutes of administration, the patient regains consciousness and his breathing improves. He is alert and cooperative within the next few minutes. Which of the following drugs was given to this patient to help alleviate his symptoms?

Question: Which of the following drugs was given to this patient to help alleviate his symptoms?

Answer: Naloxone


Context: A 22-year-old woman presents with a complaint of low energy levels for the past 6 months. She feels as if she has no energy to do anything and has lost interest in photography, which she was previously passionate about. Feelings of hopelessness occupy her mind and she can no longer focus at work. She says she forces herself to hang out with her friends at weekends but would rather stay home. She denies any suicidal ideation. Her past medical history is significant for bulimia nervosa, which was diagnosed when she was a teen and was controlled with cognitive behavioral therapy. In addition, she has gastroesophageal reflux, which is being treated with esomeprazole. The patient has a 10-pack-year smoking history but denies any alcohol or recreational drug use. On examination, she is afebrile and vital signs are within normal limits. Her BMI is 24 kg/m2. Further physical examination is unremarkable. Which of the following aspects of this patient’s history is a contraindication to using bupropion as an antidepressant?

Question: Which of the following aspects of this patient’s history is a contraindication to using bupropion as an antidepressant?

Answer: History of bulimia nervosa


Context: An 11-year-old girl presents to her pediatrician for evaluation of asymmetry that was detected during routine school screening. Specifically, she was asked to bend forwards while the school nurse examined her back. While leaning forward, her right scapula was found to be higher than her left scapula. She was also found to have a prominent line of spinal processes that diverged from the midline. She has been experiencing some back pain that she previously attributed to growth pains but otherwise has no symptoms. Her past medical history is significant only for mild allergies. She is sent to radiography for confirmation of the diagnosis and placed in a nighttime brace. Which of the following represents a complication of the most likely disease affecting this patient if it is left untreated?

Question: Which of the following represents a complication of the most likely disease affecting this patient if it is left untreated?

Answer: Restrictive lung disease


Context: A group of investigators is studying the effects of aberrant protein isoforms on the pathogenesis of lung cancer. They observe that three protein isoforms are transcribed from the same 30,160 base-pair-long DNA segment on chromosome 13q. The canonical protein has a primary peptide sequence of 1186 amino acids. The second isoform has 419 amino acids and 100% amino acid sequence homology with the canonical protein. The third isoform has 232 amino acids and 92% amino acid sequence homology with the canonical protein. Which of the following is most likely responsible for the observed phenomenon?

Question: Which of the following is most likely responsible for the observed phenomenon?

Answer: Alternative pre-mRNA splicing


Context: A 54-year-old woman comes to the physician because of paresthesias and weakness in her left leg for one year. Her symptoms have become progressively worse during this period and have led to some difficulty walking for the past month. She has had frequent headaches for the past 4 months. She has a history of hypertension and hypothyroidism. Current medications include amlodipine and levothyroxine. Her temperature is 37.3°C (99.1°F), pulse is 97/min, and blood pressure is 110/80 mm Hg. Neurologic examination shows decreased muscle strength in the left lower extremity. Deep tendon reflexes of the lower extremity are 4+ on the left and 2+ on the right side. The remainder of the examination shows no abnormalities. A complete blood count and serum concentrations of electrolytes, glucose, creatinine, and calcium are within the reference ranges. An MRI of the brain is shown. Which of the following is the most appropriate next step in management?

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

Answer: Surgical resection


Context: The rapid response team is called for a 74-year-old woman on an inpatient surgical floor for supraventricular tachycardia. The patient had surgery earlier in the day for operative management of a femur fracture. The patient has a history of hypertension, atherosclerosis, type 2 diabetes, and uterine cancer status post total abdominal hysterectomy 20 years prior. With carotid massage, valsalva maneuvers, and metoprolol, the patient breaks out of her supraventricular tachycardia. Thirty minutes later, the nurse notices a decline in the patient’s status. On exam, the patient has a temperature of 98.4°F (36.9°C), blood pressure of 102/74 mmHg, pulse of 86/min, and respirations are 14/min. The patient is now dysarthric with noticeable right upper extremity weakness of 2/5 in elbow flexion and extension. All other extremities demonstrate normal strength and sensation. Which of the following most likely contributed to this decline?

Question: Which of the following most likely contributed to this decline?

Answer: Atherosclerosis


Context: A 42-year-old woman presents with exertional dyspnea and fatigue for the past 3 months. Her past medical history is significant for multiple episodes of mild diarrhea for many years, which was earlier diagnosed as irritable bowel syndrome (IBS). She denies any current significant gastrointestinal symptoms. The patient is afebrile and vital signs are within normal limits. Physical examination reveals oral aphthous ulcers and mild conjunctival pallor. Abdominal examination is unremarkable. There is a rash present on the peripheral extremities bilaterally (see image). Laboratory findings are significant for evidence of microcytic hypochromic anemia. FOBT is negative. 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: Non-tropical sprue


Context: A 24-year-old woman in graduate school comes to the physician for recurrent headaches. The headaches are unilateral, throbbing, and usually preceded by blurring of vision. The symptoms last between 12 and 48 hours and are only relieved by lying down in a dark room. She has approximately two headaches per month and has missed several days of class because of the symptoms. Physical examination is unremarkable. The patient is prescribed an abortive therapy that acts by inducing cerebral vasoconstriction. Which of the following is the most likely mechanism of action of this drug?

Question: Which of the following is the most likely mechanism of action of this drug?

Answer: Activation of 5-HT1 receptors


Context: A 24-year-old woman comes to the physician because of pain and swelling of her left leg over the past 24 hours. The pain is worse while walking and improves when resting. Seven months ago, she was diagnosed with a pulmonary embolism and was started on warfarin. Anticoagulant therapy was discontinued 1 month ago. Her sister has systemic lupus erythematosus. The patient does not smoke. She currently takes no medications. Her temperature is 37.8°C (100°F), pulse is 78/min, and blood pressure is 123/72 mm Hg. On physical examination, the left calf is diffusely erythematous, swollen, and tender. Dorsal flexion of the left foot elicits pain. Cardiopulmonary examination shows no abnormalities. On duplex ultrasonography, the left popliteal vein is not compressible. Laboratory studies show an elevated serum concentration of D-dimer and insensitivity to activated protein C. Further examination is most likely to show which of the following?

Question: Laboratory studies show an elevated serum concentration of D-dimer and insensitivity to activated protein C. Further examination is most likely to show which of the following?

Answer: Mutation of coagulation factor V


Context: A 23-year-old woman visits her general practitioner with left ear pain and fever. She complains of multiple episodes of respiratory infection including bronchitis, laryngitis, and sinusitis. She was diagnosed with systemic lupus erythematosus with nephritis 8 months ago and was placed on oral prednisone. Currently, she takes prednisone daily. Her vital signs are as follows: blood pressure 130/85 mm Hg, heart rate 79/min, respiratory rate 16/min, and temperature 37.5°C (99.5°F). Her weight is 78 kg (172 lb) and height is 169 cm (5 ft 6 in). Physical examination reveals a swollen erythematous left eardrum, erythematous macular rash over sun-exposed skin, and slight calf edema. Inhibition of which of the following pathways causes diminished immune cell activation in this patient?

Question: Inhibition of which of the following pathways causes diminished immune cell activation in this patient?

Answer: NF-kß pathways


Context: A 16-year-old girl with celiac disease is brought to the physician because of a 1-week history of generalized weakness and tingling around her mouth and in her fingertips. She also complains of abdominal cramps and nausea. In addition to following a gluten-free diet, she has been following a vegan diet for the past 2 years. Physical examination shows involuntary contractions of the muscle at the corner of her mouth and nose that are elicited by tapping on her right cheek. Her parathyroid hormone concentration is 834 pg/mL. Which of the following is the most likely underlying cause for this patient's current condition?

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

Answer: Decreased intestinal absorption of ergocalciferol


Context: A 7-year-old girl is brought to the physician because of vaginal bleeding for 2 days. There is no personal or family history of serious illness. She is at the 95th percentile for height and at the 90th percentile for weight. Examination shows enlarged breasts, and the areola and papilla have formed a secondary mound. There is coarse pubic hair that does not extend to the inner thigh. The remainder of the examination show no abnormalities. An x-ray of the left hand and wrist shows a bone age of 11 years. Her serum luteinizing hormone concentration is 0.1 mIU/mL (N < 0.2 mIU/mL). 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: GnRH stimulation test


Context: An investigator studying disorders of hemostasis performs gene expression profiling in a family with a specific type of bleeding disorder. These patients were found to have abnormally large von Willebrand factor (vWF) multimers in their blood. Genetic analysis shows that the underlying cause is a mutation in the ADAMTS13 gene. This mutation results in a deficiency of the encoded metalloprotease, which is responsible for cleavage of vWF. Which of the following additional laboratory findings is most likely in these patients?

Question: Which of the following additional laboratory findings is most likely in these patients?

Answer: Fragmented erythrocytes


Context: A 71-year-old Caucasian male presents to your office with bloody diarrhea and epigastric pain that occurs 30 minutes after eating. He has lost 15 pounds in 1 month, which he attributes to fear that the pain will return following a meal. He has a history of hyperlipidemia and myocardial infarction. Physical exam and esophagogastroduodenoscopy are unremarkable. What is the most likely cause of this patient's pain?

Question: What is the most likely cause of this patient's pain?

Answer: Atherosclerosis


Context: A 10-year-old boy is brought to the physician with painful and enlarged lymph nodes in his right axilla that was noticed 5 days ago and has slowly grown bigger. He has had weakness, sweating, and poor appetite during this time. The boy was born at 39 weeks gestation via spontaneous vaginal delivery. He is up to date on all vaccines and is meeting all developmental milestones. He does not take any medication. There are no similar cases in the family. On physical exam, his temperature is 38.2°C (100.8°F), the pulse is 89/min, the respiratory rate is 13/min, and the blood pressure is 110/60 mm Hg. In his right axilla, there are multiple tender, flocculent, and enlarged lymph nodes with overlying erythematous skin. There is a separate lesion on the child's forearm (see image). The lesion is painless to palpation and appears inflamed. Additional history should be obtained regarding which of the following?

Question: Additional history should be obtained regarding which of the following?

Answer: Contact with pets


Context: A 4-year-old boy presents with bloody diarrhea. The patient’s mother states that he was fine this morning, but around midday, she received a call from his daycare center stating that the patient had a single bloody bowel movement. His mother states that there have been no recent changes in his diet, although they did attend a barbecue over the weekend. The patient has no recent history of fever, chills, or similar symptoms in the past. No significant past medical history. Initial laboratory studies show an elevated white blood cell (WBC) count, anemia, and a blood urea nitrogen (BUN)/creatinine ratio of 40. Stool examination shows 3+ blood but no fecal leukocytes. Which of the following tests would be diagnostic for this patient’s most likely condition?

Question: Which of the following tests would be diagnostic for this patient’s most likely condition?

Answer: Stool culture in sorbitol-MacConkey medium


Context: A 52-year-old male presents with several months of fatigue, malaise, dry cough, and occasional episodes of painless hematuria. He recalls having had a sore throat several days prior to the onset of these symptoms that resolved without antibiotics. Physical exam is remarkable for diffusely coarse breath sounds bilaterally. Urinalysis reveals 2+ protein, 2+ blood, and numerous red blood cell casts are visible under light microscopy. Which is the most likely diagnosis?

Question: Which is the most likely diagnosis?

Answer: Microscopic polyangiitis


Context: A 68-year-old man comes to the physician for a wellness visit. Physical examination shows an enlarged and nodular prostate. Laboratory studies show elevated levels of prostate-specific antigen. A prostate biopsy confirms the diagnosis of prostate cancer and a radical prostatectomy is planned. This patient should be counseled on the increased risk of injury to which of the following structures?

Question: This patient should be counseled on the increased risk of injury to which of the following structures?

Answer: Cavernous nerve


Context: An otherwise healthy 15-month-old boy is brought to the emergency department by his mother 1 hour after having a single episode of generalized tonic-clonic seizure, which stopped spontaneously after 1 minute. He was sleepy initially but is now awake and alert. His mother reports that he has had a fever and runny nose for the past 3 days. His temperature is 40.1°C (104.2°F). Physical examination shows no abnormalities. Analysis of his cerebrospinal fluid shows 3 cells/mm3, a glucose concentration of 68 mg/dL, and a protein concentration of 35 mg/dL. Administration of a drug that acts through which of the following mechanisms of action is most appropriate in this patient?

Question: Administration of a drug that acts through which of the following mechanisms of action is most appropriate in this patient?

Answer: Decreasing production of prostaglandin E2


Context:
A previously healthy 53-year-old man is brought to the emergency department 45 minutes after the onset of a severe headache. He returned from a vacation in the mountains 4 days ago, during which he went swimming in a freshwater lake. On arrival, he is confused. His temperature is 39°C (102.2°F) and blood pressure is 105/68 mm Hg. Neurologic examination shows diffuse hyperreflexia. An MRI of the brain shows asymmetrical, bitemporal hyperintensities. A lumbar puncture is performed. Cerebrospinal fluid analysis shows:
Leukocyte count 120/mm3
Segmented neutrophils 10%
Lymphocytes 90%
Erythrocyte count 15/mm3
Glucose 45 mg/dL
Opening pressure 130 mm Hg
Protein 75 mg/dL
Which of the following is the most likely causal pathogen?"

Question:
Cerebrospinal fluid analysis shows:
Leukocyte count 120/mm3
Segmented neutrophils 10%
Lymphocytes 90%
Erythrocyte count 15/mm3
Glucose 45 mg/dL
Opening pressure 130 mm Hg
Protein 75 mg/dL
Which of the following is the most likely causal pathogen?"

Answer: Herpes simplex virus


Context: A 10-year-old girl is brought to the physician because of itching of the vulva and anal region for the past 2 weeks. She has difficulty sleeping because of the itching. Physical examination shows excoriation marks around the vulva and perianal region. There is minor perianal erythema, but no edema or fissures. Microscopy of an adhesive tape applied to the perianal region shows multiple ova. Which of the following is the most appropriate treatment for this patient?

Question: Which of the following is the most appropriate treatment for this patient?

Answer: Mebendazole


Context: A 45-year-old female who recently immigrated to the United States presents to the community health clinic for episodes of disrupted vision. She is concerned because she knows several people from her hometown who went blind after having these episodes. Over the past several months, she also has developed itchy bumps on her back and lower extremities. Physical exam reveals black hyperpigmented nodules with edema and palpable lymphadenopathy, but is otherwise unremarkable without any visible discharge from the eyes. Her physician explains her underlying disease was likely transmitted by black flies. Which of the following is the most appropriate pharmacotherapy for this patient?

Question: Which of the following is the most appropriate pharmacotherapy for this patient?

Answer: Ivermectin


Context: A 10-day-old male newborn is brought to the physician by his mother because of difficulty feeding and frequent nonbilious vomiting. His stool is soft and yellow-colored. The pregnancy was complicated by polyhydramnios and results from chorionic villus sampling showed a 47, XY, +21 karyotype. Physical examination shows mild abdominal distention and normal bowel sounds. An x-ray of the abdomen with oral contrast is shown. The most likely cause of his condition is due to a defect in which of the following embryologic processes?

Question: The most likely cause of his condition is due to a defect in which of the following embryologic processes?

Answer: Rotation of the ventral pancreatic bud


Context: A 24-year-old sexually active man complains of painless growths on his penis. He is worried that he might have transmitted them to his girlfriend. Biopsy shows squamous cells with perinuclear cytoplasmic vacuolization, nuclear enlargement, and koilocytes. The doctor treats the patient by chemically ablating the warts with cryoablation. The patient encourages his girlfriend to get tested too, as he is worried she is at increased risk of developing a malignancy. Which cancer is the patient worried about?

Question: Which cancer is the patient worried about?

Answer: Cervical carcinoma


Context: A 56-year-old woman is brought to the emergency department by her husband because of slurred speech and left facial droop for the past 30 minutes. During this period, she has also had numbness on the left side of her face. She has never had such an episode before. She has hypertension, hypercholesterolemia, and type 2 diabetes mellitus. Her father died of lung cancer 1 week ago. The patient has smoked one pack of cigarettes daily for 30 years. She drinks one glass of wine daily. Her current medications include metformin, sitagliptin, enalapril, and atorvastatin. She is 168 cm (5 ft 6 in) tall and weighs 86 kg (190 lb); BMI is 30.5 kg/m2. She is oriented to time, place, and person. Her temperature is 37°C (98.7°F), pulse is 97/min, and blood pressure is 140/90 mm Hg. Examination shows drooping of the left side of the face. Her speech is clear. Examination shows full muscle strength. Deep tendon reflexes are 2+ bilaterally. A finger-nose test and her gait are normal. Cardiopulmonary examination shows a right-sided carotid bruit. A complete blood count and serum concentrations of creatinine, glucose, and electrolytes are within the reference ranges. An ECG shows left ventricular hypertrophy. A noncontrast CT scan of the brain shows no abnormalities. On the way back from the CT scan, her presenting symptoms resolve. Which of the following is the most likely diagnosis?

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

Answer: Transient ischemic attack


Context:
A 22-year-old white woman comes to the physician because of a 6-month history of lower abdominal pain. She has also had multiple episodes of loose stools with blood during this period. She has had painful bowel movements for 1 month. Over the past year, she has had a 10-kg (22-lb) weight loss. She was treated for streptococcal pharyngitis last week. Her maternal grandfather died of colon cancer at the age of 52 years. She does not smoke. She drinks three to five beers on social occasions. She is 162 cm (5 ft 4 in) tall and weighs 52 kg (115-lb); BMI is 19.7 kg/m2. Her temperature is 37°C (98.6°F), pulse is 60/min, respirations are 13/min, and blood pressure is 110/70 mm Hg. Cardiopulmonary examination shows no abnormalities. The abdomen is soft and there is tenderness to palpation of the left lower quadrant. There is no guarding or rigidity. Rectal examination shows no masses. Laboratory studies show:
Hemoglobin 10.4 g/dL
Leukocyte count 10,800/mm3
Platelet count 450,000/mm3
Serum
Na+ 138 mEq/L
Cl- 103 mEq/L
K+ 4.9 mEq/L
HCO3- 22 mEq/L
Urea nitrogen 18 mg/dL
Creatinine 0.6 mg/dL
Antinuclear antibodies negative
Perinuclear antineutrophil cytoplasmic antibodies positive
Anti-Saccharomyces cerevisiae antibodies negative
A colonoscopy is scheduled for the next day. Which of the following findings is most likely to be present on colonoscopy of this patient?"

Question: Which of the following findings is most likely to be present on colonoscopy of this patient?"

Answer: Confluent inflammation of the colonic mucosa with edema, fibrin-covered ulcers, and loss of vascular pattern


Context:
A 44-year-old woman comes to the physician with increasingly yellow sclera and pruritus over the past 3 months. She has intermittent right-upper-quadrant pain and discomfort. She has no history of any serious illnesses and takes no medications. Her vital signs are within normal limits. Her sclera are icteric. Skin examination shows linear scratch marks on the trunk and limbs. The remainder of the physical examination is unremarkable. Laboratory studies show:
Complete blood count
Hemoglobin 15 g/dL
Mean corpuscular volume 95 μm3
Leukocyte count 6,000/mm3 with a normal differential
Serum
Alkaline phosphatase 470 U/L
Aspartate aminotransferase (AST, GOT) 38 U/L
Alanine aminotransferase (ALT, GPT) 45 U/L
γ-Glutamyltransferase (GGT) 83 U/L (N=5–50 U/L)
Bilirubin, total 2.7 mg/dL
Bilirubin, direct 1.4 mg/dL
Magnetic resonance cholangiopancreatography (MRCP) shows a multifocal and diffuse beaded appearance of the intrahepatic and extrahepatic biliary ducts. Which of the following is the most appropriate diagnostic study at this time?

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

Answer: Rectosigmoidoscopy


Context: A 62-year-old woman presents with sudden onset of vertigo, difficulty walking, sensory changes on the left side of her face and the right side of the body, and left facial drooping. Her past medical history is significant for hypertension and hypercholesterolemia. On physical examination, there is left-sided Horner’s syndrome, hypoesthesia on the left side of the face, hypoesthesia on the right side of the body, left facial paralysis,  and left-sided limb ataxia, as well as dysmetria. There is also a loss of taste sensation in the anterior 2/3 of the tongue. Based on the above findings, where is the most likely location of the vascular occlusion in this patient?

Question: Based on the above findings, where is the most likely location of the vascular occlusion in this patient?

Answer: Anterior inferior cerebellar artery (AICA)


Context:
A previously healthy 15-year-old girl is brought to the emergency department 24 hours after the onset of a severe headache. She returned from a 1-week camping trip 3 days ago; she went spelunking and swimming in a freshwater lake during the trip. She is agitated, uncooperative, and oriented only to person. Her temperature is 38.9°C (102°F), pulse is 112/min, respirations are 20/min, and blood pressure is 100/68 mm Hg. There are several crusted insect bites on her extremities. Neurologic examination shows diffuse hyperreflexia and an extensor plantar response bilaterally. Her neck is supple without lymphadenopathy. An MRI of the brain shows asymmetrical, bitemporal hyperintensities. A lumbar puncture is performed. Cerebrospinal fluid analysis shows:
Opening pressure 150 mm H2O
Glucose 58 mg/dL
Protein 108 mg/dL
Leukocyte count 150/mm3
Segmented neutrophils 15%
Lymphocytes 85%
Erythrocyte count 25/mm3
Which of the following is the most likely causal pathogen?"

Question:
Cerebrospinal fluid analysis shows:
Opening pressure 150 mm H2O
Glucose 58 mg/dL
Protein 108 mg/dL
Leukocyte count 150/mm3
Segmented neutrophils 15%
Lymphocytes 85%
Erythrocyte count 25/mm3
Which of the following is the most likely causal pathogen?"

Answer: Herpes simplex virus


Context: A 60-year-old man is brought to the emergency department 25 minutes after falling and hitting his left flank on a concrete block. He has severe left-sided chest pain and mild shortness of breath. He underwent a right knee replacement surgery 2 years ago. He has type 2 diabetes mellitus. He has smoked one pack of cigarettes daily for 42 years. Current medications include metformin, sitagliptin, and a multivitamin. He appears uncomfortable. His temperature is 37.5°C (99.5°F), pulse is 102/min, respirations are 17/min, and blood pressure is 132/90 mm Hg. Pulse oximetry on room air shows an oxygen saturation of 96%. Examination shows multiple abrasions on his left flank and trunk. The upper left chest wall is tender to palpation and bony crepitus is present. There are decreased breath sounds over both lung bases. Cardiac examination shows no murmurs, rubs, or gallops. The abdomen is soft and nontender. Focused assessment with sonography for trauma is negative. An x-ray of the chest shows nondisplaced fractures of the left 4th and 5th ribs, with clear lung fields bilaterally. 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: Adequate analgesia and conservative management


Context: A 26-year-old woman presents to her primary care physician because she has been experiencing occasional fevers and chills for the last 3 weeks. She says that the fevers have been accompanied by abdominal pain and increased vaginal discharge. On presentation her temperature is 101.0°F (38.3°C), blood pressure is 113/75 mmHg, pulse is 105/min, and respirations are 12/min. On physical exam she is found to have tenderness over the lower abdominal quadrants, and speculum exam shows uterine inflammation as well as a retained intrauterine device. The most likely cause of this patient's symptoms should be treated with an antibiotic with which mechanism of action?

Question: The most likely cause of this patient's symptoms should be treated with an antibiotic with which mechanism of action?

Answer: Cell wall synthesis inhibitor


Context: A 38-year-old man comes to the physician because of a 3-week history of right-sided knee pain. He works as a bricklayer and reports that the pain worsens when he kneels. He has no history of trauma. Examination of the right knee shows erythema, fluctuant swelling, and tenderness on palpation of the kneecap. Passive flexion of the right knee elicits pain. Which of the following structures is most likely affected in this patient?

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

Answer: Prepatellar bursa


Context: A 38-year-old woman presents with anxiety. She says that, for as long as she can remember, she has been anxious, especially when at work or in social situations, which she has difficulty controlling. She also reports difficulty sleeping, irritability, and muscle tension. She says her symptoms have significantly limited her work and personal relationships. She has no other significant past medical history. The patient denies any history of smoking, alcohol consumption or recreational drug use. She is afebrile, and her vitals signs are within normal limits. A physical examination is unremarkable. Which of the following medications would be the most appropriate first-line treatment for this patient’s most likely diagnosis?

Question: Which of the following medications would be the most appropriate first-line treatment for this patient’s most likely diagnosis?

Answer: Paroxetine


Context: A 28-year-old man presents to his physician with a complaint of a 4-week history of headaches that is affecting his academic performance. Over-the-counter medications do not seem to help. He also mentions that he has to raise his head each time to look at the board when taking notes. His blood pressure is 125/75 mm Hg, pulse 86/min, respiratory rate 13/min, temperature 36.8°C (98.2°F). Ophthalmic examination shows an upward gaze palsy, convergence-retraction nystagmus, and papilledema. CT scan of the head reveals a 1.5 x 1.2 cm heterogeneous mass in the epithalamus with dilated lateral and 3rd ventricles. What other finding is most likely to be associated with this patient’s condition?

Question: What other finding is most likely to be associated with this patient’s condition?

Answer: Pseudo-Argyll Robertson pupils


Context:
A 41-year-old woman presents with acute onset severe epigastric pain radiating to the back that began a few hours ago. She also complains of nausea and has vomited twice in the past hour. She denies any history of similar symptoms or trauma in the past. Past medical history is significant for diabetes type 2 and HIV infection diagnosed 6 months ago long-standing mild intermittent asthma, and generalized anxiety disorder. She takes metformin for her diabetes but does not remember the names of her HIV medications. She reports moderate social alcohol use. Her vital signs include temperature 37.6°C (99.6 °F), pulse 95/min, blood pressure 110/74 mm Hg, respiratory rate 12/min Her body mass index (BMI) is 21 kg/m2. Laboratory findings are significant for the following:
Serum amylase: 415 U/L
Serum lipase: 520 U/L
A contrast CT of the abdomen reveals an edematous pancreas with peripancreatic fluid collection with a normal gallbladder. Which of the following is the most likely etiology of this patient’s condition?

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

Answer: HIV medication-related


Context: A 34-year-old woman presents to the emergency department with sudden onset of painful vision loss in her left eye. The patient is otherwise healthy with a history only notable for a few emergency department presentations for numbness and tingling in her extremities with no clear etiology of her symptoms. Her temperature is 100°F (37.8°C), blood pressure is 122/83 mmHg, pulse is 100/min, respirations are 15/min, and oxygen saturation is 98% on room air. Examination of the patient's cranial nerves reveals an inability to adduct the left eye when the patient is asked to look right. Which of the following is the most appropriate treatment?

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

Answer: Methylprednisolone


Context: A 24-year-old man is taken to the emergency department by local law enforcement after they witnessed him physically assaulting a complete stranger. The officers report that they saw his eyes “moving back and forth quickly” and noted that he was very red-faced. The patient has no significant past medical or psychiatric history. His vital signs include: temperature 38.0°C (100.4°F), blood pressure 110/70 mm Hg, pulse 102/min, and respiratory rate 25/min. On physical examination, the patient is belligerent and refuses to cooperate during the examination. Rotary nystagmus is noted. Which of the following drugs would most likely be present in a urine toxicology screen from this patient?

Question: Which of the following drugs would most likely be present in a urine toxicology screen from this patient?

Answer: Phencyclidine hydrochloride (PCP)


Context: A 73-year-old man presents to his primary care physician endorsing 4-5 days of decreased urinary output and mild shortness of breath. He has a complex medical history, including uncontrolled diabetes mellitus type 2, hypertension, chronic kidney disease, and end-stage emphysema. It is determined that his kidney disease has progressed to the point of needing dialysis, which his primary care physician feels should be initiated promptly. However, the patient remarks, "I would never want dialysis. I have friends who went through it, and it sounds awful. I would rather die comfortably, even if that is soon." After the physician explains what dialysis is, and the risks and alternatives to the procedure the patient is able to demonstrate his understanding of dialysis including the risks, benefits and alternatives. He appears to be in no distress and demonstrates a clear understanding. After discussing the patient's wishes further, which of the following is the most appropriate response on the part of the physician?

Question: After discussing the patient's wishes further, which of the following is the most appropriate response on the part of the physician?

Answer: "I respect that this is ultimately your decision, and will focus on making sure you are comfortable"


Context: A 26-year-old man with HIV and a recent CD4+ count of 800 presents to his PCP with fever, cough, and dyspnea. He notes that he recently lost his job as a construction worker and has not been able to afford his HAART medication. His temperature is 102.6°F (39.2°C), pulse is 75/min, respirations are 24/min, and blood pressure is 135/92 mmHg. Physical exam reveals a tachypneic patient with scattered crackles in both lungs, and labs show a CD4+ count of 145 and an elevated LDH. The chest radiography is notable for bilateral diffuse interstitial infiltrates. For definitive diagnosis, the physician obtains a sputum sample. Which stain should he use to visualize the most likely responsible organism?

Question: Which stain should he use to visualize the most likely responsible organism?

Answer: Silver stain


Context:
A 49-year-old woman is brought to the emergency department by her daughter because of increasing arthralgia, headache, and somnolence for the past week. She has a history of systemic lupus erythematosus without vital organ involvement. She last received low-dose glucocorticoids 2 months ago. Her temperature is 38.6 °C (101.5 °F), pulse is 80/min, respirations are 21/min, and blood pressure is 129/80 mm Hg. She is confused and disoriented. Examination shows scleral icterus and ecchymoses over the trunk and legs. Neurological examination is otherwise within normal limits. Laboratory studies show:
Hemoglobin 8.7 g/dL
Leukocyte count 6,200/mm3
Platelet count 25,000/mm3
Prothrombin time 15 seconds
Partial thromboplastin time 39 seconds
Fibrin split products negative
Serum
Bilirubin
Total 4.9 mg/dL
Direct 0.5 mg/dL
A blood smear shows numerous fragmented red blood cells. Urinalysis shows hematuria and proteinuria. Which of the following is the most likely diagnosis?"

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

Answer: Thrombotic thrombocytopenic purpura


Context: A 28-year-old woman comes to the physician because of a 1-year history of intermittent buzzing in both her ears. She says she sometimes has episodes of mild dizziness which resolve spontaneously. She has a 15-year history of type 1 diabetes mellitus and episodes of low back pain. She does not smoke or drink alcohol. Current medications include insulin and aspirin. She works as a trombonist for a symphony orchestra. Her vital signs are within normal limits. On otoscopic examination, the tympanic membrane appears normal. Bone conduction is greater than air conduction in both ears. Weber test shows no lateralization. Which of the following is the most likely diagnosis?

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

Answer: Otosclerosis


Context: A 25-year-old man comes to the physician for a 2-month history of abdominal discomfort, fatigue, and increased urinary frequency, especially at night. He has also noticed that despite eating more often he has lost 14-lbs (6-kg). He has a congenital solitary kidney and a history of Hashimoto thyroiditis, for which he takes levothyroxine. He has smoked two packs of cigarettes daily for 10 years. BMI is 18 kg/m2. His temperature is 36.7°C (98.1°F), pulse is 80/min, and blood pressure is 110/60 mm Hg. Physical examination is unremarkable. Serum studies show an osmolality of 305 mOsm/L and bicarbonate of 17 mEq/L. Urinalysis shows clear-colored urine with no organisms. Which of the following is most likely to be helpful in establishing the diagnosis?

Question: Which of the following is most likely to be helpful in establishing the diagnosis?

Answer: Serum glucose


Context: A 77-year-old man is brought to his primary care physician by his daughter. She states that lately, his speech has been incoherent. It seemed to have started a few weeks ago and has been steadily worsening. He is otherwise well; however, she notes that she has had to start him on adult diapers. The patient has a past medical history of hypertension, hyperlipidemia, and type 2 diabetes mellitus. He has been smoking 1 pack of cigarettes per day for over 40 years. His temperature is 98.9°F (37.2°C), blood pressure is 167/108 mmHg, pulse is 83/min, respirations are 12/min, and oxygen saturation is 97% on room air. Physical exam reveals a confused elderly man who does not respond coherently to questions. Cardiac and pulmonary exam is within normal limits. Inspection of the patient's scalp reveals a healing laceration which the daughter claims occurred yesterday when he fell while walking. Gait testing is significant for the patient taking short steps with reduced cadence. Which of the following findings is most likely in this patient?

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

Answer: Dilated ventricles on MRI


Context: A 23-year-old man comes to the physician because of a painless swelling on the left side of his jaw for 2 months. It has been progressively increasing in size and is draining thick, foul-smelling fluid. He had a molar extracted 3 months ago. Examination shows a 4-cm, tender, erythematous mass in the left submandibular region with purulent drainage. There is submandibular lymphadenopathy. A culture of the purulent material shows catalase-negative, gram-positive filamentous rods that do not stain with carbol fuchsin. Which of the following is the most likely causal pathogen?

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

Answer: Actinomyces israelii


Context: A 20-month-old boy is brought to the emergency department by his parents with fever and diarrhea that have persisted for the past 2 days. He has a history of repeated bouts of diarrhea, upper respiratory tract infections, and failure to thrive. His vital signs are as follows: blood pressure 80/40 mm Hg, pulse 130/min, temperature 39.0°C (102.2°F), and respiratory rate 30/min. Blood tests are suggestive of lymphopenia. The child is diagnosed with severe combined immune deficiency after additional testing. Which of the following is the most common association with this type of immunodeficiency?

Question: Which of the following is the most common association with this type of immunodeficiency?

Answer: X-linked severe combined immunodeficiency


Context:
A 68-year-old man seeks evaluation by a physician with complaints of worsening forgetfulness and confusion for 1 year. According to his wife, he has always been in good health and is generally very happy; however, he has started to forget important things. He recently had his driving license revoked because of multiple tickets, but he cannot recall having done anything wrong. This morning, he neglected to put on his socks and was quite agitated when she pointed this out to him. He denies having a depressed mood, sleep problems, or loss of interest. He occasionally has a glass of wine with dinner and has never smoked or used recreational drugs. His medical history and family medical history are unremarkable. His pulse is 68/min, respirations are 14/min, and blood pressure is 130/84 mm Hg. Except for a mini-mental state examination (MMSE) score of 20/30, the remainder of the physical examination is unremarkable. Imaging studies, including a chest X-ray and CT of the brain, reveal no pathologic findings. An electrocardiogram (ECG) is also normal. Laboratory testing showed the following:
Serum glucose (fasting) 76 mg/dL
Serum electrolytes:
Sodium 140 mEq/L
Potassium 4.1 mEq/L
Chloride 100 mEq/L
Serum creatinine 0.9 mg/dL
Blood urea nitrogen 11 mg/dL
Cholesterol, total: 180 mg/dL
HDL-cholesterol 45 mg/dL
LDL-cholesterol 75 mg/dL
Triglycerides 135 mg/dL
Hemoglobin (Hb%) 16 g/dL
Mean corpuscular volume (MCV)  85 fL
Reticulocyte count 0.9%
Erythrocyte count 5 million/mm³
Thyroid-stimulating hormone 3.5 µU/mL
Urinalysis
Glucose Negative
Ketones Negative
Leucocytes Negative
Nitrite Negative
RBCs Negative
Casts Negative
Which of the following is the most likely diagnosis?

Question:
Laboratory testing showed the following:
Serum glucose (fasting) 76 mg/dL
Serum electrolytes:
Sodium 140 mEq/L
Potassium 4.1 mEq/L
Chloride 100 mEq/L
Serum creatinine 0.9 mg/dL
Blood urea nitrogen 11 mg/dL
Cholesterol, total: 180 mg/dL
HDL-cholesterol 45 mg/dL
LDL-cholesterol 75 mg/dL
Triglycerides 135 mg/dL
Hemoglobin (Hb%) 16 g/dL
Mean corpuscular volume (MCV)  85 fL
Reticulocyte count 0.9%
Erythrocyte count 5 million/mm³
Thyroid-stimulating hormone 3.5 µU/mL
Urinalysis
Glucose Negative
Ketones Negative
Leucocytes Negative
Nitrite Negative
RBCs Negative
Casts Negative
Which of the following is the most likely diagnosis?

Answer: Alzheimer’s dementia


Context:
A 26-year-old woman is brought to the emergency department after a suicide attempt. Her mother found her next to an empty bottle of acetaminophen in the bathroom. The patient reports that she ingested about twenty-five 500 mg pills. She took the pills 1 hour prior to arrival to the emergency department. She has a history of major depressive disorder. She does not smoke or use illicit drugs. Current medications include fluoxetine. She is oriented to person, place, and time. Vital signs are within normal limits. Physical examination shows no abnormalities. Laboratory studies show:
Hemoglobin 12.5 g/dL
Leukocyte count 8,000/mm3
Platelet count 150,000/mm3
Serum
Prothrombin time 10.5 sec (INR=1.0)
Na+ 141 mEq/L
K+ 4.2 mEq/L
Cl- 101 mEq/L
HCO3- 25 mEq/L
Urea nitrogen 10 g/dL
Creatinine 0.5 g/dL
Ca2+ 8.8 mg/dL
Total bilirubin 0.4 mg/dL
AST 22 U/L
ALT 25 U/L
Alkaline phosphatase 62 U/L
Which of the following is the most appropriate next step in management?"

Question:
Laboratory studies show:
Hemoglobin 12.5 g/dL
Leukocyte count 8,000/mm3
Platelet count 150,000/mm3
Serum
Prothrombin time 10.5 sec (INR=1.0)
Na+ 141 mEq/L
K+ 4.2 mEq/L
Cl- 101 mEq/L
HCO3- 25 mEq/L
Urea nitrogen 10 g/dL
Creatinine 0.5 g/dL
Ca2+ 8.8 mg/dL
Total bilirubin 0.4 mg/dL
AST 22 U/L
ALT 25 U/L
Alkaline phosphatase 62 U/L
Which of the following is the most appropriate next step in management?"

Answer: Administer activated charcoal


Context: A 42-year-old woman is brought to the physician by her husband because she cries frequently and refuses to get out of bed. Over the past 3 weeks, she has been feeling sad and tired most of the time. She has difficulty staying asleep at night and often wakes up early in the morning. After losing her job as a waitress 1 month ago, she has been feeling guilty for not contributing to the household income anymore. She would like to find a new position but is unable to decide “what to do with her life”. She was diagnosed with anorexia nervosa at age 18 and has gone to psychotherapy several times since then. Her weight had been stable for the past 5 years; however, within the past 3 weeks, she has had a 2.8-kg (6.2-lb) weight loss. She would like to regain some weight. She is 160 cm (5 ft 3 in) tall and currently weighs 47 kg (104 lb); BMI is 18.4 kg/m2. Her temperature is 36.3°C (97.3°F), pulse is 58/min, and blood pressure is 110/60 mm Hg. Physical examination shows no abnormalities. Mental status examination shows a depressed mood and flat affect. There is no evidence of suicidal ideation. Which of the following drugs is most likely to address both this patient's mood disorder and her desire to gain weight?

Question: Which of the following drugs is most likely to address both this patient's mood disorder and her desire to gain weight?

Answer: Mirtazapine


Context: A 2-month-old girl with a previous diagnosis of DiGeorge syndrome is brought to the emergency department with her parents following a seizure. Her mother states that the baby had been inconsolable all day and refused to feed. She was born at 39 weeks gestation via spontaneous vaginal delivery. She is up to date on all vaccines. Upon arrival to the hospital her heart rate is 120/min, respiratory rate is 40/min, and temperature of 37.0°C (98.6°F). On examination, she is afebrile and somnolent and her fontanelles are open and soft. While attempting to take her blood pressure, the patient’s arm and hand flex sharply and do not relax until the cuff is released. A light tap on the cheek results in an atypical facial muscle twitch. A CMP and CBC are drawn and sent for analysis. Which of the following is the most likely cause?

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

Answer: Hypocalcemia


Context: A 2900-g (6.4-lb) male newborn is delivered at term to a 29-year-old primigravid woman. His mother had no routine prenatal care. She reports that the pregnancy was uncomplicated apart from a 2-week episode of a low-grade fever and swollen lymph nodes during her early pregnancy. She has avoided all routine vaccinations because she believes that “natural immunity is better.” The newborn is at the 35th percentile for height, 15th percentile for weight, and 3rd percentile for head circumference. Fundoscopic examination shows inflammation of the choroid and the retina in both eyes. A CT scan of the head shows diffuse intracranial calcifications and mild ventriculomegaly. Prenatal avoidance of which of the following would have most likely prevented this newborn's condition?

Question: Prenatal avoidance of which of the following would have most likely prevented this newborn's condition?

Answer: Undercooked pork


Context: A 6-year-old girl is brought to the physician for a well-child examination. There is no personal or family history of serious illness. She is at the 90th percentile for height and weight. Vital signs are within normal limits. Examination shows enlarged breast buds that extend beyond the areola. There is coarse pubic hair that does not extend onto the inner thigh. The remainder of the examination show no abnormalities. An x-ray of the left hand shows a bone age of 10 years. Following GnRH agonist stimulation, serum luteinizing hormone levels increase to twice the median. Which of the following is the most appropriate next best step in management?

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

Answer: MRI of the brain


Context: A 67-year-old female presents to the emergency room with dry cough and malaise. She has no other complaints. She has a past medical history of a meningioma status post resection complicated by hemiplegia and has been managed with dexamethasone for several months. Her vital signs are T 100.4 F (38 C), O2 93% on room air, RR 20, BP 115/75 mmHg. Physical examination is notable for crackles bilaterally. A chest radiograph is obtained (Image A). The patient is admitted and initially treated guideline-compliant antibiotics for community-acquired pneumonia. Unfortunately, her respiratory function deteriorates. An arterial blood gas is drawn. On room air at sea level, PaO2 is 71 mmHg and PaCO2 is 34 mmHg. Induced sputum samples reveal organisms on methenamine silver stain. What is the best treatment strategy for this patient?

Question: What is the best treatment strategy for this patient?

Answer: Trimethoprim-sulfamethoxazole + steroids


Context: You are called to see a chemotherapy patient who is complaining of severe nausea. This patient is a 52-year-old male with acute lymphoblastic leukemia (ALL) who began his first cycle of chemotherapy 2 days ago. Which of the following structures is involved in the pathway responsible for this patient's nausea?

Question: Which of the following structures is involved in the pathway responsible for this patient's nausea?

Answer: Medulla oblongata


Context: A 52-year-old tow truck driver presents to the emergency room in the middle of the night complaining of sudden onset right ankle pain. He states that the pain came on suddenly and woke him up from sleep. It was so severe that he had to call an ambulance to bring him to the hospital since he was unable to drive. He has a history of hypertension and types 2 diabetes mellitus, for which he takes lisinopril and methotrexate. He has no other medical problems. The family history is notable for hypertension on his father’s side. The vital signs include: blood pressure 126/86 mm Hg, heart rate 84/min, respiratory rate 14/min, and temperature 37.2°C (99.0°F). On physical exam, the patient’s right ankle is swollen, erythematous, exquisitely painful, and warm to the touch. An arthrocentesis is performed and shows negatively birefringent crystals on polarized light. Which of the following is the best choice for treating this patient’s pain?

Question: Which of the following is the best choice for treating this patient’s pain?

Answer: Administer indomethacin


Context: A 63-year-old man with a history of diabetes mellitus presents with complaints of fatigue. He lives alone and has not seen a doctor in 10 years. He does not exercise, eats a poor diet, and drinks 1-2 beers per day. He does not smoke. He has never had a colonoscopy. Labs show a hemoglobin of 8.9 g/dL (normal 13.5 - 17.5), mean corpuscular volume of 70 fL (normal 80-100), serum ferritin of 400 ng/mL (normal 15-200), TIBC 200 micrograms/dL (normal 250-420), and serum iron 50 micrograms/dL (normal 65-150). Which of the following is the cause of his abnormal lab values?

Question: Which of the following is the cause of his abnormal lab values?

Answer: Chronic inflammation


Context: A 37-year-old woman, gravida 3, para 3, comes to the physician for a follow-up examination. She gave birth to her third child 8 months ago and now wishes to start a contraception method. Prior to her most recent pregnancy, she used a combined estrogen-progestin pill. Which of the following aspects of her history would be a contraindication for restarting an oral contraceptive pill?

Question: Which of the following aspects of her history would be a contraindication for restarting an oral contraceptive pill?

Answer: She smokes 1 pack of cigarettes daily


Context: A 15-year-old boy is brought to the physician by his mother because of 4 months of strange behavior. She says that during this period, he has had episodic mood swings. She has sometimes found him in his room “seemingly drunk” and with slurred speech. These episodes usually last for approximately 15 minutes, after which he becomes irritable. He has had decreased appetite, and his eyes occasionally appear red. He has trouble keeping up with his schoolwork, and his grades have worsened. Physical examination shows an eczematous rash between the upper lip and nostrils. Neurologic examination shows a delay in performing alternating palm movements. Use of which of the following is the most likely cause of this patient's condition?

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

Answer: Inhalants


Context: A 40-year-old woman comes to the physician because of a small lump on the right side of her neck that she noticed while putting lotion on 1 week ago. She does not have any weight change, palpitations, or altered bowel habits. There is no family history of serious illness. Menses occur at regular 30-day intervals and lasts for 4 days. She appears well. Her temperature is 37°C (98.6° F), pulse is 88/min, and blood pressure is 116/74 mm Hg. Examination shows a small swelling on the right side of the neck that moves with swallowing. There is no lymphadenopathy. Ultrasound of the neck shows a 0.9-cm (0.35-in) right lobe thyroid mass with microcalcifications and irregular margins. Which of the following is the most appropriate next step in diagnosis?

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

Answer: Thyroid-stimulating hormone level


Context: A 36-year-old woman, gravida 2, para 1, at 26 weeks' gestation comes to the emergency department because of a gush of clear fluid from her vagina that occurred 1 hour prior. She reports painful pelvic cramping at regular 5-minute intervals. She has missed most of her prenatal care visit because of financial problems from her recent divorce. Her first child was delivered vaginally at 27 weeks' gestation due to spontaneous preterm labor. She has smoked one pack of cigarettes daily for 15 years but has reduced her intake to 2–3 cigarettes per day since finding out she was pregnant. She continues to use cocaine once a week. Vital signs are within normal limits. Sterile speculum examination shows fluid pooling in the vagina, and nitrazine paper testing confirms the presence of amniotic fluid. Which of the following puts her at highest risk of preterm delivery?

Question: Which of the following puts her at highest risk of preterm delivery?

Answer:
History of spontaneous preterm birth
"


Context: A 52-year-old woman comes to the physician because of a 3-week history of pain in her right knee. The pain is worse at the end of the day and when she walks. She says that it has become difficult for her to walk up the flight of stairs to reach her apartment. She has hypertension and psoriasis. Her sister has rheumatoid arthritis. She drinks 2–3 beers daily. Current medications include hydrochlorothiazide, topical betamethasone, and a multivitamin. She is 160 cm (5 ft 3 in) tall and weighs 92 kg (202 lb); BMI is 36 kg/m2. She appears anxious. Her temperature is 37°C (98.6°F), pulse is 87/min, and blood pressure is 135/83 mm Hg. Cardiopulmonary examinations shows no abnormalities. There are several scaly plaques over the patient's upper and lower extremities. The right knee is not tender nor erythematous; range of motion is limited. Crepitus is heard on flexion and extension of the knee. Her hemoglobin concentration is 12.6 g/dL, leukocyte count is 9,000/mm3, and erythrocyte sedimentation rate is 16 mm/h. An x-ray of the right knee is shown. Which of the following is the most appropriate next step in the management of this patient?

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

Answer: Weight loss program


Context: A 12-year-old female with no past medical history is found to have an abnormal cardiovascular exam during routine physical examination at her pediatrician’s office. All other components of her physical exam are normal. During evaluation for potential causes for her abnormal exam, an echocardiogram with doppler is done that shows flow between the atria. Which of the following would would have most likely been auscultated as a result of the pathology on her echocardiogram?

Question: Which of the following would would have most likely been auscultated as a result of the pathology on her echocardiogram?

Answer: Splitting of S2 in inspiration and expiration


Context: As part of a clinical research study, microscopic analysis of tissues obtained from surgical specimens is performed. Some of these tissues have microscopic findings of an increase in the size of numerous cells within the tissue with an increase in the amount of cytoplasm, but the nuclei are uniform in size. Which of the following processes shows such microscopic findings?

Question: Which of the following processes shows such microscopic findings?

Answer: Uterine myometrium in pregnancy


Context: A 42-year-old man comes to the physician because of a 3-year history of urinating up to 20 times each day. He has not had any dysuria and nocturia. He has been evaluated by several urologists but has not received a specific diagnosis despite extensive diagnostic testing. Various pharmacologic treatments have not improved his symptoms. He quit his job 1 year ago and stopped attending social events because his frequent urination has been disruptive. He spends most of his time at the library trying to learn what could be causing his symptoms. He would like to undergo a CT scan of his entire body to evaluate for cancer. Physical examination and laboratory studies show no abnormalities. Mental status examination shows a depressed mood and constricted affect. There is no evidence of suicidal ideation. Which of the following is the most likely explanation for this patient's symptoms?

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

Answer: Somatic symptom disorder


Context: A 62-year-old woman is brought to the emergency department of a busy suburban hospital because of a 1-week history of nausea and vomiting. She also has had intermittent fevers and headaches during the past 5 weeks. She does not have a stiff neck or sensitivity to light. She appears tired. Her temperature is 37°C (98.6°F), pulse is 70/min, respirations are 15/min, and blood pressure is 135/85 mm Hg. She is alert and oriented to person, place, and time. Examination shows no abnormalities. A lumbar puncture is performed, and cerebrospinal fluid (CSF) is collected for analysis. On the way to the laboratory, the physician loses the CSF specimens. The physician decides that a repeat lumbar puncture should be performed. Before giving consent for the second procedure, the patient asks what the results are from the specimens obtained earlier. Which of the following responses by the physician is the most appropriate?

Question: Which of the following responses by the physician is the most appropriate?

Answer: """I was unable to obtain results from the earlier tests because I misplaced the specimens. I sincerely apologize for the mistake."""


Context:
A 74-year-old woman with a past medical history of hypertension, peripheral artery disease, and migraine headaches presents to the emergency department with a two hour history of severe abdominal pain. The patient cannot recall any similar episodes, although she notes occasional abdominal discomfort after eating. She describes the pain as sharp periumbilcal pain. She denies recent illness, fever, chills, nausea, vomiting, or diarrhea. Her last normal bowel movement was yesterday evening. Her temperature is 37.1°C (98.8°F), pulse is 110/min, blood pressure is 140/80 mmHg, and respirations are 20/min. On exam, the patient is grimacing and appears to be in significant discomfort. Heart and lung exams are within normal limits. The patient’s abdomen is soft and non-distended with diffuse periumbilical pain on palpation. There is no rebound tenderness or guarding, and bowel sounds are present. The rest of the exam is unremarkable. Labs in the emergency room show:

Serum:
Na+: 144 mEq/L
Cl-: 105 mEq/L
K+: 3.7 mEq/L
HCO3-: 20 mEq/L
BUN: 15 mg/dL
Glucose: 99 mg/dL
Creatinine: 1.2 mg/dL
Ca2+: 10.7 mg/dL
Phosphorus: 5.2 mg/dL
Lactate: 7.0 mmol/L
Amylase: 240 U/L

Hemoglobin: 13.4 g/dL
Hematocrit: 35%
Leukocyte count: 12,100 cells/mm^3 with normal differential
Platelet count: 405,000/mm^3

What is the next best step in diagnosis?

Question:
Labs in the emergency room show:

Serum:
Na+: 144 mEq/L
Cl-: 105 mEq/L
K+: 3.7 mEq/L
HCO3-: 20 mEq/L
BUN: 15 mg/dL
Glucose: 99 mg/dL
Creatinine: 1.2 mg/dL
Ca2+: 10.7 mg/dL
Phosphorus: 5.2 mg/dL
Lactate: 7.0 mmol/L
Amylase: 240 U/L

Hemoglobin: 13.4 g/dL
Hematocrit: 35%
Leukocyte count: 12,100 cells/mm^3 with normal differential
Platelet count: 405,000/mm^3

What is the next best step in diagnosis?

Answer: CT angiography


Context: A 39-year-old man presents to his primary care physician with a 10-hour history of severe diarrhea. He says that he was recently at a company picnic and after returning home he began to experience severe watery diarrhea. He says that the diarrhea was accompanied by nausea and abdominal pain. His physician informs him that he was likely infected by a lactose-fermenting, gram-negative organism. Which of the following changes would be seen in a cell that was affected by the heat stable toxin produced by this organism?

Question: Which of the following changes would be seen in a cell that was affected by the heat stable toxin produced by this organism?

Answer: Increased cyclic guanosine monophosphate


Context: An investigator is studying the structure of the amino-terminal of the Huntingtin protein using x-ray crystallography. The terminal region is determined to have an α-helix conformation. Which of the following forces is most likely responsible for maintaining this conformation?

Question: Which of the following forces is most likely responsible for maintaining this conformation?

Answer: Hydrogen bonds


Context: A 65-year-old man with a past medical history of anterior myocardial infarction, peripheral arterial disease, and known patent foramen ovale presents to the emergency department after being found down from a fall on the sidewalk in the middle of winter. He states that his right leg feels numb and painful at the same time. He insists that he did not slip on ice or snow, yet fell suddenly. He is taking aspirin, simvastatin, and cilastazol. Vital signs show T 98.0 F, BP 100/60, HR 100, RR 18. His pulse is irregularly irregular. His right leg appears pale with no dorsalis pedis and posterior tibial pulses compared to 2+ pulses on the left. He cannot discern soft or sharp touch in his right leg. Which intervention will most likely improve the viability of this patient's right leg?

Question: Which intervention will most likely improve the viability of this patient's right leg?

Answer: Catheter-based thrombectomy / thrombolysis


Context: A 3-year-old boy is brought to the physician by his parents for the evaluation of easy bruising for several months. Minor trauma also causes scratches that bleed. Two months ago, a fall from his bed caused a large forehead hematoma and a left elbow laceration. He sometimes does not eat because of pain while chewing. Vital signs are within normal limits. Examination shows that the skin can be stretched further than normal and is fragile. Range of motion of the joints is slightly increased. There is tenderness to palpation of the temporomandibular joints bilaterally. 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: Defective type V collagen


Context:
A 64-year-old male presents to the emergency room with difficulty breathing. He recently returned to the USA following a trip to Singapore. He reports that he developed pleuritic chest pain, shortness of breath, and a cough. His temperature is 99°F (37.2°C), blood pressure is 140/85 mmHg, pulse is 110/min, and respirations are 24/min. A spiral CT reveals a pulmonary embolus in the right segmental pulmonary artery. Results from a complete blood count are all within normal limits. He is admitted and started on unfractionated heparin. Four days later, the patient develops unprovoked epistaxis. A complete blood count reveals the following:

Leukocyte count: 7,000/mm^3
Hemoglobin: 14 g/dl
Hematocrit: 44%
Platelet count 40,000/mm^3

What is the underlying pathogenesis of this patient’s condition?

Question:
A complete blood count reveals the following:

Leukocyte count: 7,000/mm^3
Hemoglobin: 14 g/dl
Hematocrit: 44%
Platelet count 40,000/mm^3

What is the underlying pathogenesis of this patient’s condition?

Answer: Autoantibodies directed against platelet factor 4


Context: An autopsy is performed on a 39-year-old man 5 days after he was found pulseless at his apartment by his neighbor. Examination of the brain shows liquefactive necrosis in the distribution of the right middle cerebral artery with surrounding edema. Immunophenotyping of a sample of the affected brain tissue shows numerous cells that express CD40 on their surface. On further histopathological evaluation, the morphology of these cells is not readily discernible with Nissl stain. These histological findings are most consistent with which of the following cell types?

Question: These histological findings are most consistent with which of the following cell types?

Answer: Microglia


Context: A recent study shows that almost 40% of the antibiotics prescribed by primary care physicians in the ambulatory setting are for patients with a clinical presentation consistent with a viral acute respiratory tract infection. Recent evidence suggests that the implementation of a set of interventions may reduce such inappropriate prescribing. Which of the following strategies, amongst others, is most likely to achieve this goal?

Question: Which of the following strategies, amongst others, is most likely to achieve this goal?

Answer: Local peer comparison


Context: A 14-year-old boy is brought to the physician for generalized fatigue and mild shortness of breath on exertion for 3 months. He has a history of recurrent patellar dislocations. He is at the 99th percentile for height and at the 30th percentile for weight. His temperature is 37°C (98.6°F), pulse is 99/min, and blood pressure is 140/50 mm Hg. Examination shows scoliosis, a protruding breast bone, thin extremities, and flat feet. Ocular examination shows upwards displacement of bilateral lenses. A grade 3/6 early diastolic murmur is heard along the left sternal border. Further evaluation of this patient is most likely to show which of the following?

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

Answer: Water hammer pulse


Context: A 17-year old girl is brought to the physician by her mother because menarche has not yet occurred. She is at the 3rd percentile for height. Examination of a buccal mucosal scraping shows several cells with a single dark body attached to the nuclear membrane. Karyotyping of a neutrophil shows 45 chromosomes. Which of the following is the most likely underlying cause of this patient's cytogenetic abnormality?

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

Answer: Postzygotic mitotic error


Context:
A 3-month-old boy is brought to the emergency department by his mother after a seizure at home. The mother is not sure how long the seizure lasted, but says that the boy was unresponsive and had episodes of stiffness and jerking of his extremities throughout the episode. The mother states that the boy has not seemed himself for the past several weeks and has been fussy with feeds. He does not sleep through the night. He has not had any recent infections or sick contacts.

On exam, the boy is lethargic. His temperature is 99.5°F (37.5°C), blood pressure is 70/40 mmHg, and pulse is 120/min. He has no murmurs and his lungs are clear to auscultation bilaterally. His abdomen appears protuberant, and his liver span is measured at 4.5 cm below the costal margin. Additionally, the boy has abnormally enlarged cheeks. A finger stick in the ED reveals a blood glucose level of 35 mg/dL. What would this patient’s response to a fasting-state glucagon stimulation test most likely be, and what enzyme defect does he have?

Question: What would this patient’s response to a fasting-state glucagon stimulation test most likely be, and what enzyme defect does he have?

Answer: No change in plasma glucose; glucose-6-phosphatase


Context: A 4-year-old boy is brought to the emergency department for evaluation of a fever for 1 day. The mother reports that he has had severe pain in his lower extremities and difficulty eating since yesterday. He has not had a cough, nausea, or vomiting. He was born at term and has been healthy. His immunizations are up-to-date. He appears irritable. His temperature is 38.5°C (101.3°F). Examination shows several flesh-colored, tender papules over the trunk, knees, palms, and soles. There are multiple 2-mm, reddish macules on the hard palate. The remainder of the examination shows no abnormalities. Which of the following is the most likely causal organism of this patient's symptoms?

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

Answer: Coxsackie A virus


Context: After the administration of an erroneous dose of intravenous phenytoin for recurrent seizures, a 9-year-old girl is resuscitated because of bradycardia and asystole. Later, the patient is taken to the critical care unit and placed on mechanical ventilation. Neurologic consultation shows hypoxic brain injury. To reduce the incidence of similar events, which of the following is the most appropriate next step in management?

Question: To reduce the incidence of similar events, which of the following is the most appropriate next step in management?

Answer: Root cause analysis


Context: A 70-year-old chronic smoker presents to the emergency department with a sudden onset of left-sided weakness. The past medical history is insignificant except for hypertension, for which he has been taking medications regularly. The vital signs include: blood pressure 165/110 mm Hg, pulse rate 78/min, respiratory rate 18/min, and temperature 36.1°C (97°F). The neurologic examination shows ⅗ muscle strength in the left upper and lower limbs. An occlusion of a branch of the right middle cerebral artery is suspected because the CT fails to show signs of hemorrhage. The HbA1C is 11%. Which of the following blood lipid components is the most important contributing factor leading to his condition?

Question: Which of the following blood lipid components is the most important contributing factor leading to his condition?

Answer: Oxidized low-density lipoprotein (ox-LDL)


Context: An 80-year-old man comes to the office for evaluation of anemia. His medical history is relevant for end-stage renal disease and aortic stenosis. When questioned about his bowel movements, the patient mentions that he has occasional episodes of loose, black, tarry stools. His heart rate is 78/min, respiratory rate is 17/min, temperature is 36.6°C (97.8°F), and blood pressure is 80/60 mm Hg. Physical examination shows pale skin and conjunctiva and orthostasis upon standing. A complete blood count shows his hemoglobin is 8.7 g/dL, hematocrit is 27%, and mean corpuscular volume is 76 μm3. A colonoscopy is obtained. Which of the following is the most likely cause of this patient’s current condition?

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

Answer: Angiodysplasia


Context: A 69-year-old man with history of coronary artery disease necessitating angioplasty and stent placement presents to the ED due to fever, chills, and productive cough for one day. He is started on levofloxacin and admitted because of his comorbidity and observed tachypnea of 35 breaths per minute. He is continued on his home medications including aspirin, clopidogrel, metoprolol, and lisinopril. He cannot ambulate as frequently as he would like due to his immediate dependence on oxygen. What intervention should be provided for deep venous thrombosis prophylaxis in this patient while hospitalized?

Question: What intervention should be provided for deep venous thrombosis prophylaxis in this patient while hospitalized?

Answer: Low molecular weight heparin


Context: A 68-year-old woman presents to the physician with complaints of unexplained weight loss of approximately 5 kg (11.02 lb) over the last 6 months. Her other complaints include repeated stomatitis and diarrhea for 1 year. She was diagnosed with diabetes mellitus 1 year ago. Her temperature is 36.9°C (98.4°F), heart rate is 84/min, respiratory rate is 16/min, and blood pressure is 126/82 mm Hg. Physical examination reveals multiple, confluent, erythematous papules, plaques and bullous lesions over the extremities, the perioral region, and the perigenital region. An oral examination shows angular cheilitis, glossitis, and stomatitis. Which test is most likely to yield an accurate diagnosis for this patient?

Question: Which test is most likely to yield an accurate diagnosis for this patient?

Answer: Serum glucagon


Context: A 55-year-old man comes to the physician because of increasing swelling of the legs and face over the past 2 months. During this time, he has experienced fatigue and weight loss. He has no history of any serious illness and takes no medications. Vital signs are within normal range. On physical examination, both lower limbs show significant pitting edema extending above the knees. A photograph of the patient’s facial features is shown. His urinary protein is 3 g/24 h. Serum and urine electrophoresis shows monoclonal light chains. Skeletal survey shows no osteolytic lesions. Without treatment, which of the following is the most likely clinical course for this patient?

Question: Without treatment, which of the following is the most likely clinical course for this patient?

Answer: Death within 1–2 years


Context: A six-month-old infant presents with chronic, persistent diarrhea, oral thrush, and a severe diaper rash. The infant was treated four weeks ago for an upper respiratory and ear infection. A family history is significant for a consanguineous relationship between the mother and father. Physical examination demonstrates the absence of palpable lymph nodes. Accumulation of which of the following would lead to this disease phenotype?

Question: Accumulation of which of the following would lead to this disease phenotype?

Answer: Deoxyadenosine


Context: A 19-year-old Caucasian college student is home for the summer. Her parents note that she has lost quite a bit of weight. The daughter explains that the weight loss was unintentional. She also notes an increase in thirst, hunger, and urine output. Her parents decide to take her to their family physician, who suspects finding which of the following?

Question: Her parents decide to take her to their family physician, who suspects finding which of the following?

Answer: Elevated ketone levels


Context: An 84-year-old woman with Alzheimer's disease is brought to the physician by her son for a follow-up examination. The patient lives with her son, who is her primary caregiver. He reports that it is becoming gradually more difficult to care for her. She occasionally has tantrums and there are times when she does not recognize him. She sleeps 6–8 hours throughout the day and is increasingly agitated and confused at night. When the phone, television, or oven beeps she thinks she is at the dentist's office and becomes very anxious. She eats 2–3 meals a day and has a good appetite. She has not fallen. She has not left the home in weeks except for short walks. She has a history of hypertension, hyperlipidemia, atrial fibrillation, and hypothyroidism. She takes levothyroxine, aspirin, warfarin, donepezil, verapamil, lisinopril, atorvastatin, and a multivitamin daily. Her temperature is 37°C (98.4°F), pulse is 66/min, respirations are 13/min, and blood pressure is 126/82 mm Hg. Physical examination shows no abnormalities. It is important to the family that the patient continues her care in the home. Which of the following recommendations is most appropriate at this time?

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

Answer: Adhere to a regular sleep schedule


Context: A 24-year-old man is hospitalized for an elective gastrointestinal surgery 24 hours before the scheduled day of surgery. The surgeon has ordered food and fluids to be withheld from the patient from 12 hours before the surgery and the administration of intravenous isotonic saline. Based on his body weight, his fluid requirement for 12 hours is 900 mL. However, the following day, the surgeon finds that 3 pints of isotonic fluid (1 pint = 500 mL) were administered over the preceding last 12 hours. Which of the following options best describes the resulting changes in the volume of intracellular fluid (ICF) and the body osmolality of the patient?

Question: Which of the following options best describes the resulting changes in the volume of intracellular fluid (ICF) and the body osmolality of the patient?

Answer: No change in ICF volume, no change in body osmolality


Context: A 50-year-old man presents to the emergency department with a complaint of crushing chest pain. The pain started suddenly 30 minutes ago while he was walking his dog. The patient also complains of difficulty breathing and palpitations. The pain is described as starting behind the sternum and moving towards the left jaw. Medical history includes recently diagnosed hypercholesterolemia and peptic ulcer disease. He currently takes atorvastatin and omeprazole. The patient has smoked a pack of cigarettes per day for 10 years and consumes 2–3 beers on the weekends. His blood pressure is 148/90 mm Hg, the pulse is 106/min, and the respiratory rate is 22/min. Examination shows him to be visibly distressed, diaphoretic, and slightly hunched over. Aspirin is administered and blood work is sent to the laboratory. His ECG is shown in the picture. What is the best next step for this patient?

Question: What is the best next step for this patient?

Answer: Urgent percutaneous coronary intervention


Context: A 25-year-old man is brought to the emergency department by his wife for evaluation of abnormal behavior that began 2 weeks ago. The patient has not slept in over a week and has been partying each night. He has never done this before. The patient has also been skipping work and purchased a car last week with money they had saved for their vacation to Italy. He has a past medical history of major depressive disorder and systemic lupus erythematosus. He normally drinks 2 beers per week but has been drinking 6–10 beers per day for the past two weeks. Current medications include hydroxychloroquine. He appears agitated and is wearing bright-colored mismatched clothing. His temperature is 36°C (96.8°F), pulse is 94/min, respirations are 18/min, and blood pressure is 130/85 mm Hg. Physical examination shows no abnormalities. On mental status examination, his speech is pressured and his thought process is tangential. A complete blood count, serum electrolytes, and liver enzyme activities are within the reference range; his serum creatinine is 1.8 mg/dL. Urinalysis shows 2+ proteinuria, and WBC casts. Toxicology screening is negative. This patient would most likely benefit from which of the following long-term treatments?

Question: This patient would most likely benefit from which of the following long-term treatments?

Answer: Valproate


Context:
A 30-year-old caucasian female comes to the physician because of chronic diarrhea and abdominal bloating that started 6 months ago. She also reports increasing fatigue and intermittent tingling in her hands and feet. She lost 5 kg (11 lb) of weight over the past 6 months without changing her diet or trying to lose weight. She and her husband have been trying to conceive for over a year without any success. Menses have been irregular at 28–45 day intervals and last for 1–2 days. She has generalized anxiety disorder for which she takes sertraline. Her height is 151 cm and weight is 50 kg; BMI is 22 kg/m2. Examination shows generalized pallor. Cardiopulmonary examination is normal. Test of the stool for occult blood is negative. Laboratory studies show:
Hemoglobin 9.5 g/dL
Leukocyte count 3900/mm3
Platelet count 130,000/mm3
Serum
Glucose 100 mg/dL
Creatinine 0.6 mg/dL
Thyroid-stimulating hormone 3.3 μU/mL
Vitamin B12 80 pg/mL (N > 200)
IgA anti-tissue transglutaminase antibody negative
Serum IgA decreased
Which of the following is the most appropriate next step in diagnosis?"

Question:
Laboratory studies show:
Hemoglobin 9.5 g/dL
Leukocyte count 3900/mm3
Platelet count 130,000/mm3
Serum
Glucose 100 mg/dL
Creatinine 0.6 mg/dL
Thyroid-stimulating hormone 3.3 μU/mL
Vitamin B12 80 pg/mL (N > 200)
IgA anti-tissue transglutaminase antibody negative
Serum IgA decreased
Which of the following is the most appropriate next step in diagnosis?"

Answer: IgG deamidated gliadin peptide test


Context: A 7-year-old boy presents with difficulty swallowing, diarrhea, itching, and weakness. He also complains of episodes of headaches, sweating, and palpitations, which are accompanied by fear and tend to end with micturition. His mother is concerned about the strange nodules on his lips and eyelids. The boy's younger brother had similar nodules and died at 10 years of age of unknown causes. The patient’s vital signs are as follows: blood pressure 130/80 mm Hg, heart rate 107/min, respiratory rate 14/min, and temperature 36.9℃ (98.4℉). The child is tall, thin, has disproportionately long arms and legs, and increased thoracic spine kyphosis. There are multiple yellow-white, sessile, painless nodules on the patient’s lips, and buccal and eyelid mucosa. There is a painless lump in the area of the left thyroid lobe and enlargement of the posterior cervical lymph nodes on the left side. What is the most probable embryonic origin of the cells in the lump?

Question: What is the most probable embryonic origin of the cells in the lump?

Answer: Neural crest cells


Context: A 42-year-old woman with well-controlled HIV on antiretroviral therapy comes to the physician because of a 2-week history of a painless lesion on her right calf. Many years ago, she had a maculopapular rash over her trunk, palms, and soles that resolved spontaneously. Physical examination shows a 4-cm firm, non-tender, indurated ulcer with a moist, dark base and rolled edges. There is a similar lesion at the anus. Results of rapid plasma reagin testing are positive. Which of the following findings is most likely on microscopic examination of these lesions?

Question: Which of the following findings is most likely on microscopic examination of these lesions?

Answer: Coagulative necrosis surrounded by fibroblast and macrophage infiltrate


Context: A 58-year-old man presents to his primary care physician with a 3-week history of increasing pain in his legs and feet. Specifically, he says that he has been getting electric shock sensations that started in his feet, but have progressed up his leg. In addition, the pain is accompanied by numbness and tingling in his hands and feet bilaterally. His past medical history is significant for poorly controlled type 2 diabetes mellitus. Given these symptoms, his physician prescribes a new drug to help him cope with these symptoms. Which of the following is the mechanism of action for the medication that was most likely prescribed in this case?

Question: Which of the following is the mechanism of action for the medication that was most likely prescribed in this case?

Answer: Serotonin norepinephrine reuptake inhibitor


Context: A 22-year-old soldier sustains a stab wound to his chest during a military attack in Mali. He is brought to the combat medic by his unit for a primary survey. The soldier reports shortness of breath. He is alert and oriented to time, place, and person. His pulse is 99/min, respirations are 32/min, and blood pressure is 112/72 mm Hg. Examination shows a 2-cm wound at the left fourth intercostal space at the midclavicular line. Bubbling of blood is seen with each respiration at the wound site. There is no jugular venous distention. There is hyperresonance to percussion and decreased breath sounds on the left side. The trachea is at the midline. 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: Partially occlusive dressing


Context: A 22-year-old G1P1 woman comes to the clinic asking about “the morning after pill.” She reports that she had sexual intercourse with her boyfriend last night and she thinks the condom broke. She is not using any other form of contraception. She reports her last menstrual period was 10 days ago, and they are normally regular. The patient’s medical history is significant for obesity, asthma and allergic rhinitis. Her medications include albuterol and occasional intranasal corticosteroids. She has no history of sexually transmitted diseases and is sexually active with only her current boyfriend of 5 years. The patient denies genitourinary symptoms. Her temperature is 98°F (36.7°C), blood pressure is 112/74 mmHg, pulse is 63/min, and respirations are 12/min with an oxygen saturation of 99% O2 on room air. Physical examination, including a pelvic exam, shows no abnormalities. The patient is worried because she is back in graduate school and cannot afford another child. Which of the following is the most effective emergency contraception?

Question: Which of the following is the most effective emergency contraception?

Answer: Copper intrauterine device


Context: A 15-year-old adolescent boy presents to his pediatrician for his scheduled follow-up after he was prescribed low-dose methylphenidate for treatment of attention-deficit/hyperactivity disorder 4 weeks ago. On follow-up, his mother reports mild improvement in his symptoms, but she also notes that his appetite has decreased significantly after starting the medication. This has led to a 1.6 kg (3.5 lb) weight loss over the last 4 weeks. His mother also reports that she no longer wants to continue the drug. Which of the following is the next drug of choice for pharmacological management of the condition?

Question: Which of the following is the next drug of choice for pharmacological management of the condition?

Answer: Atomoxetine


Context: An investigator is studying the metabolism of an experimental drug that is known to have first order kinetics. Immediately after administering an intravenous dose of the drug to a patient, the serum concentration is 60 U/L. 3 hours later, the serum concentration of the drug is 30 U/L. 9 hours after administration, the serum concentration of the drug is most likely to be which of the following?

Question: 9 hours after administration, the serum concentration of the drug is most likely to be which of the following?

Answer: 7.5 U/L


Context: A 26-year-old gravida-1-para-0 (G-1-P-0) presents for a routine prenatal check-up at 16 weeks gestation. The patient has no concerns but is excited to learn the gender of the baby. Genetic testing was performed that showed an XY genotype; however, an ultrasound does not reveal the development of external male genitalia. Which of the following is responsible for the initial step of the development of male characteristics?

Question: Which of the following is responsible for the initial step of the development of male characteristics?

Answer: SRY gene product


Context: An 82-year-old woman presents to the emergency department after a fall. Imaging reveals diffuse trauma to the left humerus from the midshaft to the olecranon process with shearing of the periosteum. The orthopedic surgeon suggests a follow-up in 2 weeks. In that time, the patient develops worsening pain. At follow-up, she is found to have diffuse bone necrosis from the midshaft of the left humerus to the olecranon process. with no involvement of the distal arm structures. Which of the following structures must have been damaged to cause this diffuse bone necrosis?

Question: Which of the following structures must have been damaged to cause this diffuse bone necrosis?

Answer: Volkmann’s canal


Context: A 7-year-old boy with a sore throat, fever, and generalized malaise is admitted to the pediatric floor. On physical examination, he has diffuse white exudate on both tonsils, and also a palpable spleen with mild hepatomegaly. His blood smear shows large and abundant lymphocytes with blue-gray cytoplasm, irregular nuclei, and dark chromatin with inconspicuous nucleoli. Which of the following is the most likely diagnosis?

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

Answer: Infectious mononucleosis


Context: A 71-year-old man is brought to the emergency department because of severe, progressive left leg pain and tingling for 8 hours. The symptoms began while he was watching television. For several months, the patient has noticed calf cramping when going for long walks, as well as occasional foot tingling and numbness, but did not seek medical attention. He has no history of recent injuries. He has poorly-controlled hypertension, hyperlipidemia, type 2 diabetes mellitus, and osteoarthritis. He smoked one pack of cigarettes daily for 35 years but quit 15 years ago. He drinks three beers every night. Current medications include lisinopril, metoprolol succinate, atorvastatin, metformin, and ibuprofen. He appears to be in severe pain and is clutching his left leg. His temperature is 37.4°C (99.3°F), pulse is 110/min, respirations are 18/min, and blood pressure is 163/94 mm Hg. The lungs are clear to auscultation. There is a harsh II/VI systolic ejection murmur best heard at the right upper sternal border. The abdomen is soft and nontender. The left leg is cool to the touch with decreased popliteal, posterior tibial, and dorsalis pedis pulses. There is 5/5 strength on left hip, knee, and ankle testing. The left hip, knee, and ankle show no gross effusion, erythema, or tenderness to palpation. The remainder of the examination shows no abnormalities. Which of the following is most likely to confirm the diagnosis?

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

Answer: Digital subtraction angiography


Context:
A 28-year-old gravida 2 para 1 is receiving care from her obstetrician at 28 weeks. She states that she has been having suprapubic pain and urinary frequency for the past week. Her past medical history is significant for dermatomyositis for which she takes prednisone every day. She does not smoke cigarettes or drinks alcohol. Her vital signs are within normal limits. Physical examination of the patient is within normal limits. A urine sample from the patient shows > 100,000 CFU of Escherichia coli. Urinalysis results are provided as follows:
Leukocyte esterase  positive
WBC 50-100 cells/HPF
Nitrite positive
RBC 2 cells/HPF
Epithelial cells 2 cells/HPF
Urine pH 5.2
Which of the following is the best pharmacotherapy for this patient’s condition?

Question:
Urinalysis results are provided as follows:
Leukocyte esterase  positive
WBC 50-100 cells/HPF
Nitrite positive
RBC 2 cells/HPF
Epithelial cells 2 cells/HPF
Urine pH 5.2
Which of the following is the best pharmacotherapy for this patient’s condition?

Answer: Nitrofurantoin


Context: A 43-year-old woman visits her primary care physician complaining of abdominal pain for the past 6 months. She reports that the pain is localized to her lower abdomen and often resolves with bowel movements. She states that some days she has diarrhea while other times she will go 4-5 days without having a bowel movement. She started a gluten-free diet in hopes that it would help her symptoms, but she has not noticed much improvement. She denies nausea, vomiting, hematochezia, or melena. Her medical history is significant for generalized anxiety disorder and hypothyroidism. Her father has a history of colon cancer. The patient takes citalopram and levothyroxine. Physical examination reveals mild abdominal tenderness with palpation of lower quadrant but no guarding or rebound. A guaiac test is negative. A complete blood count is pending. Which of the following is the next best step in management?

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

Answer: Colonoscopy


Context: A 26-year-old woman comes to the physician because of severe pain in her right wrist one day after falling onto her hands and knees while rollerskating. Physical examination shows abrasions over the knees and bruising over the volar aspect of the right wrist. There is swelling and tenderness on palpation of the volar wrist joint, as well as restricted range of motion due to pain. An x-ray of the hand shows volar dislocation of the lunate bone. Further evaluation is most likely to show which of the following?

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

Answer: Paresthesia over the volar aspect of the first 3 fingers on wrist flexion


Context: A 56-year-old man with hypertension comes to the physician for a follow-up examination. His blood pressure is 165/92 mm Hg on the left arm and 162/90 mm Hg on the right arm. He reports that he is compliant with his medication and exercise regimen. The physician adds a drug to his antihypertensive medication regimen. This drug increases serum renin, angiotensin I, and angiotensin II levels, and decreases serum aldosterone levels, without affecting bradykinin levels. Which of the following drugs was most likely added to this patient's medication regimen?

Question: Which of the following drugs was most likely added to this patient's medication regimen?

Answer: Candesartan


Context:
A 65-year-old man comes to the physician because of a 6-month history of muscle weakness. During this period, the patient has had low energy, intermittent nosebleeds, and a 5-kg (11-lb) weight loss. He also reports progressive hearing and vision problems. He has a history of pins-and-needles sensation, numbness, and pain in his feet. Vital signs are within normal limits. Physical examination shows a palpable liver tip 2–3 cm below the right costal margin. There is nontender lympadenopathy in the groins, axillae, and neck. Laboratory studies show:
Hemoglobin 8.8 g/dL
White blood cells 6,300/mm3
Platelet count 98,000/mm3
Erythrocyte sedimentation rate 70 mm/h
Serum
Na+ 136 mmol/L
K+ 3.6 mmol/L
Cr 1.3 mg/dL
Ca2+ 8.6 mg/dL
Aspartate aminotransferase 32 U/L
Alanine aminotransferase 36 U/L
Alkaline phosphatase 100 U/L
Lactate dehydrogenase 120 U/L
A serum protein electrophoresis exhibits a sharp, narrow spike of monoclonal IgM immunoglobulin. Which of the following is the most likely diagnosis?"

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

Answer: Waldenstrom macroglobulinemia


Context: A previously healthy 6-week-old infant is brought to the emergency department because of fever, fatigue, and dry cough for one day. She has been feeding poorly and had difficulty latching on to breastfeed since yesterday. She has had nasal congestion. The mother reports that her daughter has not been going through as many diapers as usual. She was born by uncomplicated vaginal delivery at 42 weeks' gestation. Her mother is a cystic fibrosis carrier. The patient has been treated with acetaminophen for the last 24 hours, and vitamin D drops since birth. She appears irritable, pale, and lethargic. She is at the 25th percentile for both length and weight; she had the same percentiles at birth. Her temperature is 38.2°C (100.7°F) and respirations are 64/min. Pulse oximetry on room air shows an oxygen saturation of 92%. Examination shows an ill-appearing infant with a cough and nasal flaring. Mucous membranes are dry. Chest examination shows intercostal and supraclavicular retractions. Expiratory wheezes are heard on auscultation. Which of the following is the most likely causal organism?

Question: Which of the following is the most likely causal organism?

Answer: Respiratory syncytial virus


Context: A 38-year-old woman presents to the physician’s clinic with a 6-month history of generalized weakness that usually worsens as the day progresses. She also complains of the drooping of her eyelids and double vision that is worse in the evening. Physical examination reveals bilateral ptosis after a sustained upward gaze and loss of eye convergence which improves upon placing ice packs over the eyes and after the administration of edrophonium. Which of the following is an intrinsic property of the muscle group affected in this patient?

Question: Which of the following is an intrinsic property of the muscle group affected in this patient?

Answer: High ATPase activity