Review Question - QID 101937

In a 2-year-old, an outpouching of tissue from the ileum containing all 3 parts of the intestinal wall is most likely a Meckel's diverticulum, which may become inflamed and result in diverticulitis (abdominal pain in this patient).

Meckel's diverticulum is a congenital anomaly of the intestine. In the embryo, the omphalomesenteric duct (also known as the vitelline duct or yolk stalk) connects the midgut lumen to the yolk sac. It normally obliterates during the 7th week of embryonic development. If it persists, it results in a small bulge in the intestine present at birth known as Meckel's diverticulum. Meckel's diverticulum is a "true" diverticulum; it contains mucosa, submucosa, and the muscular layer. Meckel's diverticulum may be remembered with the "Rules of 2": It occurs in 2% of the population, in the first 2 years of life, and 2 feet from the ileocecal valve.

Incorrect Answers:
Answer 1: Hirschprung's disease is congenital megacolon due to failure of neural crest cell migration.
Answer 2: Crohn's disease is characterized by non-caseating granulomas and skip lesions.
Answer 4: The appendix is a true diverticulum of the cecum. The specimen in this case was removed from the ileum. However, Meckel's diverticulum may mimic appendicitis!
Answer 5: Henoch-Schonlein purpura (IgA vasculitis) may cause abdominal pain in slightly older children and is always accompanied by nonthrombocytopenic palpable purpura, not a feature of this case.