A Case of Adenocarcinoma Arising from the Gastric Ectopic Pancreas

Abstract

We report an extremely rare case of gastric submucosal adenocarcinoma arising from the ectopic pancreas. A 64-year-old man followed up for pleural disease was found in chest computerized tomography (CT) to have an enhanced 3cm tumor on the prepyloric greater curvature. Gastrointestinal endoscopy showed a smoothsurfaced solid tumor covered with intact mucosa in the prepylorus, and endoscopic ultrasonography showed a hypoechoic mass mainly located in the proper muscle layer. Retrospective reconfirmation of the previous CT showed that the 2-year-old tumor had remained almost unchanged in size. Since pyloric obstruction occurred just before operation, we conducted laparoscopic pylotectmy on a preoperative diagnosis of gastrointestinal stromal tumor of the stomach. Intraoperative pathological examination showed distributed tubular structures and a suspected ectopic pancreas. Postoperative histological examination diagnosed adenocarcinoma arising from the ectopic pancreas, because this tumor, occupying the submucosal layer to subserosa, consisted of transition between normal ductal epithelium and epithelial cancer cells. It is thus important to consider the coexistence of malignancy in submucosal tumor.