Image Challenge Q: A 23-day-old male infant was brought to the emergency department after 5 days of increasing vomiting. Physical exam revealed mild dehydration and an olive-sized abdominal mass. Upper gastrointestinal radiography showed a distended, air-filled stomach. What is the likely diagnosis? 1. Gastric duplication 2. Pyloric stenosis 3. Duodenal atresia 4. Intestinal malrotation 5. Mid-gut volvulus
Image Challenge Q: A 23-day-old male infant was brought to the emergency department after 5 days of increasing vomiting. Physical exam revealed mild dehydration and an olive-sized abdominal mass. Upper gastrointestinal radiography showed a distended, air-filled stomach. What is the likely diagnosis? Answer: Pyloric stenosis The correct answer is pyloric stenosis. The radiograph reveals undulating contours of the stomach -— known as the “caterpillar” sign -— visible when hyperperistaltic waves end abruptly at the pylorus, characteristic of infantile hypertrophic pyloric stenosis.