ABIM MCQ 5

Question 1

A 35-year-old woman presents with recurrent episodes of severe abdominal pain, vomiting, and port-wine colored urine precipitated by fasting and oral contraceptive use. Urine porphobilinogen is markedly elevated during attacks. What is the most appropriate acute treatment?

Accepted Answer

IV hemin (heme arginate) and glucose loading

Answer

Acute attacks of acute intermittent porphyria are treated with IV hemin, which represses ALA synthase, and high glucose loading to suppress the heme biosynthesis pathway.

Question 2

A 67-year-old man with CLL presents with worsening fatigue and pallor. Hemoglobin is 7.1 g/dL, MCV 92, reticulocyte count 8%. Direct antiglobulin test (DAT) is positive for IgG. LDH is elevated. What is the diagnosis?

Accepted Answer

Autoimmune hemolytic anemia (AIHA)

Answer

Warm AIHA is the most common hematologic complication of CLL, presenting with a positive DAT for IgG, elevated LDH, and increased reticulocyte count reflecting hemolysis.

Question 3

A 48-year-old woman with known mitral stenosis and atrial fibrillation presents with acute onset left hemiplegia and facial droop. MRI brain confirms ischemic stroke. She is outside the tPA window. Her INR was 1.4 yesterday. What is the most appropriate anticoagulation strategy going forward?

Accepted Answer

Warfarin with goal INR 2.0-3.0

Answer

Rheumatic mitral stenosis with atrial fibrillation is an indication for warfarin; DOACs like apixaban are not approved for this indication due to inferior outcomes in valvular AF.

Question 4

A 57-year-old man with HIV on ART (CD4 450 cells/µL, undetectable viral load) presents with progressive vision loss in his right eye. Ophthalmology exam shows a 'pizza pie' fundus appearance with perivascular hemorrhages and exudates. What is the most likely diagnosis?

Accepted Answer

CMV retinitis

Answer

CMV retinitis presents with the classic 'pizza pie' or 'scrambled eggs and ketchup' fundus appearance and occurs in severe immunosuppression, though can rarely occur at higher CD4 counts.

Question 5

A 73-year-old woman is admitted with decompensated heart failure. She is started on IV furosemide but develops worsening creatinine (1.4 → 2.1 mg/dL) despite improving pulmonary congestion. What is this phenomenon called and what should be done?

Accepted Answer

Cardiorenal syndrome — continue diuresis if congestion persists

Answer

Cardiorenal syndrome type 1 involves AKI from decompensated HF; continued gentle diuresis is appropriate if the patient remains fluid overloaded, as congestion itself harms the kidneys.

ABIM - American Board of Internal Medicine Practice Test

ABIM - American Board of Internal Medicine Practice Test

ABIM MCQ 5