Small Bowel, Meckel's diverticulum

Meckel’s diverticulum is a remnant of the omphalomesenteric or vitelline duct. Clinically, it presents in 2% of the population and is frequently seen in the first 2 years of life. Grossly, it is 2 inches long and located 2 feet from the ileocecal valve, and consists of 2 or more types of glandular epithelium ("the rule of 2’s").

Microscopic features:
- ectopic gastric and/or pancreatic mucosa
- comprising all layers of GI tract (true diverticulum)

Differential diagnosis includes appendicitis.