Diagnostic parsimony (Occam's razor) — MCQs

A mother presents to the family physician with her 16-year-old son. She explains, "There's something wrong with him doc. His grades are getting worse, he's cutting class, he's gaining weight, and his eyes are often bloodshot." Upon interviewing the patient apart from his mother, he seems withdrawn and angry at times when probed about his social history. The patient denies abuse and sexual history. What initial test should be sent to rule out the most likely culprit of this patient's behavior?

A 65-year-old obese man presents to his primary care clinic feeling weak. He was in the military and stationed in Vietnam in his youth. His current weakness gradually worsened to the point that he had to call his son to help him stand to get on the ambulance. He smokes a pack of cigarettes every day and drinks a bottle of vodka a week. He has been admitted for alcohol withdrawal multiple times and has been occasionally taking thiamine, folic acid, and naltrexone. He denies taking steroids. His temperature is 98°F (36.7°C), blood pressure is 170/90 mmHg, pulse is 75/min, and respirations are 20/min. He is obese with a significant pannus. Hepatomegaly is not appreciable. Abdominal striae are present. His workup is notable for the following: Serum: Na+: 142 mEq/L Cl-: 102 mEq/L K+: 3.9 mEq/L HCO3-: 25 mEq/L BUN: 24 mg/dL Glucose: 292 mg/dL Creatinine: 1.5 mg/dL Ca2+: 10.1 mg/dL AST: 7 U/L ALT: 14 U/L 24-hour urinary cortisol: 400 µg (reference range < 300 µg) Serum cortisol: 45 pg/mL (reference range < 15 pg/mL) A 48-hour high dose dexamethasone suppression trial shows that his serum cortisol levels partially decrease to 25 pg/mL and his adrenocorticotropin-releasing hormone (ACTH) level decreases from 10 to 6 pg/mL (reference range > 5 pg/mL). What is the best next step in management?

A 52-year-old man comes to the physician because of a 3-week history of a cough and hoarseness. He reports that the cough is worse when he lies down after lunch. His temperature is 37.5°C (99.5°F); the remainder of his vital signs are within normal limits. Because the physician has recently been seeing several patients with the common cold, the diagnosis of a viral upper respiratory tract infection readily comes to mind. The physician fails to consider the diagnosis of gastroesophageal reflux disease, which the patient is later found to have. Which of the following most accurately describes the cognitive bias that the physician had?

A 55-year-old man presents to his primary care physician for a new patient appointment. The patient states that he feels well and has no concerns at this time. The patient has a past medical history of hypertension, an elevated fasting blood glucose, and is not currently taking any medications. His blood pressure is 177/118 mmHg, pulse is 90/min, respirations are 16/min, and oxygen saturation is 97% on room air. Physical exam is notable for an obese man with atrophy of his limbs and striae on his abdomen. Laboratory values are notable for a blood glucose of 175 mg/dL. Which of the following is the best next step in evaluation?

A 34-year-old female presents to her primary care physician with complaints of fevers, nausea/vomiting, and severe left flank pain that has developed over the past several hours. She denies any prior episodes similar to her current presentation. Physical examination is significant for a body temperature of 39.1 C and costovertebral angle tenderness. A urinalysis and urine microscopy are ordered. Which of the following findings on kidney histology would be expected in this patient?

A 28-year-old male presents to his primary care physician with complaints of intermittent abdominal pain and alternating bouts of constipation and diarrhea. His medical chart is not significant for any past medical problems or prior surgeries. He is not prescribed any current medications. Which of the following questions would be the most useful next question in eliciting further history from this patient?

A 65-year-old man is admitted to the hospital because of a 1-month history of fatigue, intermittent fever, and weakness. Results from a peripheral blood smear taken during his evaluation are indicative of possible acute myeloid leukemia. Bone marrow aspiration and subsequent cytogenetic studies confirm the diagnosis. The physician sets aside an appointed time-slot and arranges a meeting in a quiet office to inform him about the diagnosis and discuss his options. He has been encouraged to bring someone along to the appointment if he wanted. He comes to your office at the appointed time with his daughter. He appears relaxed, with a full range of affect. Which of the following is the most appropriate opening statement in this situation?

A 55-year-old man presents to the emergency department with fatigue and a change in his memory. The patient and his wife state that over the past several weeks the patient has been more confused and irritable and has had trouble focusing. He has had generalized and non-specific pain in his muscles and joints and is constipated. His temperature is 99.3°F (37.4°C), blood pressure is 172/99 mmHg, pulse is 79/min, respirations are 14/min, and oxygen saturation is 99% on room air. Physical exam is unremarkable. Laboratory studies are ordered as seen below. Hemoglobin: 9.0 g/dL Hematocrit: 30% Leukocyte count: 6,500/mm^3 with normal differential Platelet count: 166,000/mm^3 MCV: 78 fL Serum: Na+: 141 mEq/L Cl-: 103 mEq/L K+: 4.6 mEq/L HCO3-: 25 mEq/L BUN: 20 mg/dL Glucose: 99 mg/dL Creatinine: 0.9 mg/dL Ca2+: 10.2 mg/dL Which of the following is the most likely diagnosis?

A 27-year-old woman presents to the emergency department for fever and generalized malaise. Her symptoms began approximately 3 days ago, when she noticed pain with urination and mild blood in her urine. Earlier this morning she experienced chills, flank pain, and mild nausea. Approximately 1 month ago she had the "flu" that was rhinovirus positive and was treated with supportive management. She has a past medical history of asthma. She is currently sexually active and uses contraception inconsistently. She occasionally drinks alcohol and denies illicit drug use. Family history is significant for her mother having systemic lupus erythematosus. Her temperature is 101°F (38.3°C), blood pressure is 125/87 mmHg, pulse is 101/min, and respirations are 18/min. On physical examination, she appears uncomfortable. There is left-sided flank, suprapubic, and costovertebral angle tenderness. Urine studies are obtained and a urinalysis is demonstrated below: Color: Amber pH: 6.8 Leukocyte: Positive Protein: Trace Glucose: Negative Ketones: Negative Blood: Positive Nitrite: Positive Leukocyte esterase: Positive Specific gravity: 1.015 If a renal biopsy is performed in this patient, which of the following would most likely be found on pathology?

A 57-year-old man presents to the emergency department for weight loss and abdominal pain. The patient states that he has felt steadily more fatigued over the past month and has lost 22 pounds without effort. Today, he fainted prompting his presentation. The patient has no significant past medical history. He does have a 33 pack-year smoking history and drinks 4 to 5 alcoholic drinks per day. His temperature is 99.5°F (37.5°C), blood pressure is 100/58 mmHg, pulse is 100/min, respirations are 17/min, and oxygen saturation is 98% on room air. On physical exam, you see a patient who is very thin and appears to be pale. Stool fecal occult blood testing is positive. A CT scan of the abdomen is performed demonstrating a mass in the colon with multiple metastatic lesions scattered throughout the abdomen. The patient is informed of his diagnosis of metastatic colon cancer. When the patient conveys the information to his family he focuses his efforts on discussing the current literature in the field and the novel therapies that have been invented. He demonstrates his likely mortality outcome which he calculated using the results of a large multi-center study. Which of the following is this patient most likely demonstrating?