Small intestine & ampulla
Congenital anomalies
Heterotopic pancreas
Author: Hanni Gulwani, M.B.B.S.
Last author update: 1 August 2012
Last staff update: 26 April 2023
Copyright: 2003-2024, PathologyOutlines.com, Inc.
PubMed Search: Heterotopic pancreas[TIAB] small bowel
Table of Contents
Definition / general | Gross description | Microscopic (histologic) description | Differential diagnosis | Additional referencesCite this page: Gulwani H. Heterotopic pancreas. PathologyOutlines.com website. https://www.pathologyoutlines.com/topic/smallbowelheterotopicpancreas.html. Accessed April 26th, 2024.
Definition / general
- Also called adenomyoma, myoepithelial hamartoma (although without pancreatic tissue)
- Incidence of 1 - 14%, affects all ages but peaks in 4 - 6th decade
- Most common near ampulla of Vater; also stomach, jejunum
- May cause blockage of duct, leading to infection, cystic dilation and fat necrosis
- Usually incidental finding at surgery submitted for frozen section but carcinoma may arise from pancreatic heterotopia (Arch Pathol Lab Med 1999;123:707)
Gross description
- Submucosal nodule, intramural mass
- Yellowish white, lobulated, 0.2 - 4 cm
- May have central mucosal dimple
Microscopic (histologic) description
- Widely separated pancreatic acini with minimally developed ducts, well formed acini may be seen (JOP 2007;8:588, Mod Pathol 2003;16:530)
- Pancreatic heterotopia may be total, only ducts, only acinar cells (exocrine heterotopia), only islet cells (endocrine heterotopia)
- Adenomyoma: predominance of pancreatic ducts with proliferation of thick smooth muscle bundles of the muscularis around the ducts (seen in periampullary region of the duodenum)
Differential diagnosis
- Cystic change in pancreatic heterotopia from duplication
- Neuroendocrine tumor from endocrine heterotopia
- Well differentiated adenocarcinoma
Additional references
