A 3-Month-Old With Failure to Thrive and Persistent Vomiting.

A 3-month-old boy was admitted from his pediatrician's office for failure to thrive and vomiting. On admission, he weighed barely more than his birth weight and was cachectic with muscle wasting. His abdomen was grossly distended but soft and nontender. A trial of nasogastric feeds resulted in a worsening of his clinical status. He was transferred to the ICU, and diagnostic imaging was concerning for a distal bowel obstruction. Surgical pathology revealed a surprising diagnosis, which is described in detail in the following case.