Pancreatic intraepithelial neoplasia arising from an ectopic pancreas in the small bowel.

Background: Ectopic pancreatic tissue is relatively uncommon, and is characterized as pancreatic tissue with no contact with the normal pancreas, and with its own ductal system and blood supply. It is usually asymptomatic, and can be incidentally diagnosed by conventional imaging studies.

Method: A 69-year-old woman with a prior history of bilateral breast carcinoma presented with ectopic pancreatic intraepithelial neoplasia (PanIN) that was identified incidentally in the small bowel during an oncological resection of a synchronous primary pancreatic adenocarcinoma, and renal cell carcinoma.

Results: The patient underwent subtotal pancreatectomy with splenectomy, regional lymphadenectomy, radical left nephrectomy, and small bowel resection with primary anastomosis of ectopic PanIN-2. She had an uneventful hospitalization and was discharged home on postoperative day 7.

Conclusions: The occurrence of ectopic PanIN is extremely unusual with only few cases previously reported in the literature. The need for negative margins after surgical resection of ectopic PanIN lesions remains controversial.