A Case of Ectopic Pancreatic Cancer in the Stomach after Recurrent Phlegmonous Gastritis

Abstract

A 51-year-old woman had first complained of fever and abdominal pain 19 years earlier. Investigations at that time showed a submucosal tumorous lesion with cyst formation and thickening of the wall of the gastric antrum, and she was treated conservatively for phlegmonous gastritis. She subsequently developed the same condition seven times, each time improving with conservative treatment. One month before presenting on the most recent occasion she had developed loss of appetite and abdominal pain, and upper gastrointestinal endoscopy showed enlargement of the submucosal tumorous lesion in the gastric antrum. Computed tomography also showed a mass in the greater omentum, and surgery for a suspected malignant tumor was performed. Intraoperative findings were indicative of gastric cancer with peritoneal dissemination, and distal gastrectomy was performed with the objective of avoiding pyloric stenosis. Postoperative histopathological testing confirmed that the submucosal tumorous gastric cancer was mucoid carcinoma, and the tumor contained vestiges of islets of Langerhans, suggesting that it may have been derived from ectopic pancreas. In this case, ectopic pancreas was the cause of the clinically repeated phlegmonous gastritis, and it developed into gastric cancer over the long term. It is often difficult to make a definitive diagnosis of gastric submucosal tumors, and even more careful follow-up may have been needed taking into account the possibility that they may turn cancerous over the long term.