Diabetes Mellitus USMLE Step 1 Practice Question
A 49-year-old woman with type 2 diabetes presents with profuse watery diarrhea persisting despite 24-hour fasting, muscle weakness, and facial flushing. Vital signs show BP 118/76 mmHg, HR 102/min, RR 16/min, temp 37.2°C. Laboratory studies reveal serum potassium 2.8 mEq/L, gastric pH 6.2 with markedly reduced acid secretion, and fasting glucose 156 mg/dL. Abdominal imaging shows no obstruction. She takes metformin and lisinopril. Which diagnosis best explains her presentation?
Answer choices
- ACarcinoid tumor
- BGlucagonoma
- CInsulinoma
- DGastrinoma
- EVIPomaCorrect answer
- FSomatostatinoma
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