Pancreatic acini and dilated ducts are seen within the submucosa of the jejunum.
Normal jejunum is seen on the upper right with underlying pancreatic tissue.
Heterotopic pancreas (also known as ectopic pancreas, or pancreatic rest) can arise in the stomach, duodenum, jejunum and Meckel's diverticulum. One-third of cases arise in the stomach centered mostly in the antrum or pylorus (Cheng, Iacobuzio).
Although rarely symptomatic or clinical significant, it is important for pathologists to recognize this entity as it can form small nodules or occasionally larger masses and thus be submitted for frozen section. On cut section, the mass is submucosal with a yellow lobulated appearance similar to normal pancreas (Iacobuzio).
Histologically, pancreatic acini, ducts and islet cells can be seen. Rarely, the heterotopic tissue is composed only of acinar cells, or ducts, or islets.
Mostly asymptomatic. Can occasionally present with abdominal pain, vomiting and bleeding.
If symptomatic, excision is performed.
Benign. Exceptionally, pancreatitis and malignancy (islet cell tumor or pancreatic ductal adenocarcinoma) can develop from the ectopic pancreatic tissue.
Cheng L, Bostwick DG, eds. Essentials of Anatomic Pathology. 2nd Ed. Totowa, NJ: Humana Press; 2006: 1300.
Iacobuzio-Donahue CA, Montgomery EA. Gastrointestinal and Liver Pathology: Foundations in Diagnostic Pathology. Philadelphia, PA: Elsevier; 2005: 107-110.