Embryology USMLE Step 1 Practice Question
A 2-day-old male newborn presents with persistent nonbilious vomiting after each feeding. Vital signs show HR 155 bpm, RR 42/min, temp 37.2Ā°C, BP 65/40 mmHg. Upper GI imaging reveals circumferential narrowing of the second portion of the duodenum by pancreatic tissue. Serum electrolytes show hypochloremic hypokalemic metabolic alkalosis. No bilious drainage noted. Which embryologic abnormality most likely caused this anatomic finding?
Answer choices
- AFailure of fusion of pancreatic buds
- BFailure of recanalization
- CAbnormal migration of ventral pancreatic budCorrect answer
- DFrontonasal prominence
- ELateral palatine shelves
- FPancreas divisum
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