Ectopic gastric pancreatic cancer: report of a case.

It is very rare for ectopic pancreas to become cancerous. We herein report on a case of ectopic pancreatic cancer developed in the stomach. A neoplastic lesion was detected in the pyloric part in an upper GIS of a 76-year-old female, requiring biopsy, but because it was classified as Group I, it was observed temporarily. Following blood collection after approximately 2 years, the CA19-9 increased from 177.5 to 279.5, so a GIS was again performed. Although the pyloric part of the stomach became more stenosed than before, it was still considered Group I disease based on biopsy findings. When EUS was performed, the tumor appeared as a submucosal tumor, and was thus suspected as GIST. In an abdominal CT, a neoplastic lesion with a clear boundary was observed in the pylorus, as was an enlarged lymph node in the hepatoduodenal ligament. Therefore malignancy could not be ruled out, and a gastrectomy on the pylorus side, lymph node dissection (D2), and cholecystectomy were performed. The tumor was a submucosal tumor covered by a coherent mucosa. According to histopathological findings, it was diagnosed as ectopic pancreatic cancer developed in the ectopic pancreas (Heinrich type II), consisting of acinar tissue and capillary tubes. Thus ectopic pancreas should be considered in the differential diagnosis of gastric submucosal tumors. Regarding surgery for ectopic pancreas, it is considered necessary to establish a treatment policy by making an immediate pathological diagnosis with sufficient consideration of the possibility of malignancy.