ECFMG Medical Knowledge & Clinical Science 5

Question 1

A 25-year-old woman presents with episodic pallor followed by cyanosis then rubor of her fingers triggered by cold. Which condition is this MOST characteristic of?

Accepted Answer

Raynaud's phenomenon

Answer

Raynaud's phenomenon is characterized by the classic triphasic color change (white→blue→red) in digits triggered by cold or stress.

Question 2

A 3-year-old boy has recurrent Staphylococcus and Aspergillus infections. Neutrophil oxidative burst is absent on dihydrorhodamine test. What is the defective enzyme?

Accepted Answer

NADPH oxidase

Answer

Chronic granulomatous disease results from NADPH oxidase deficiency, preventing the respiratory burst needed to kill catalase-positive organisms.

Question 3

A 58-year-old man presents with progressive dysphagia first to solids then to liquids, 15 lb weight loss, and a new hoarse voice. Barium swallow shows a mid-esophageal irregularity. What is the most likely histology?

Accepted Answer

Squamous cell carcinoma

Answer

Mid-esophageal carcinoma is most commonly squamous cell carcinoma, associated with tobacco and alcohol use, unlike distal esophageal adenocarcinoma.

Question 4

A 66-year-old woman has bone pain, serum protein electrophoresis showing an M-spike, and Bence Jones proteins in urine. Skeletal survey reveals lytic lesions. What finding on bone marrow biopsy would confirm the diagnosis?

Accepted Answer

>10% plasma cells

Answer

Multiple myeloma is confirmed by >10% clonal plasma cells on bone marrow biopsy in the appropriate clinical context.

Question 5

A patient develops sudden-onset severe headache described as 'the worst headache of my life.' CT head is negative. What is the NEXT step?

Accepted Answer

Lumbar puncture for xanthochromia

Answer

A negative CT does not exclude subarachnoid hemorrhage; lumbar puncture for xanthochromia is mandatory when clinical suspicion is high.

(ECFMG) Educational Commission for Foreign Medical Graduates Practice Test

(ECFMG) Educational Commission for Foreign Medical Graduates Practice Test

ECFMG Medical Knowledge & Clinical Science 5