Abstract
A 74-year-old man who visited a neighboring hospital because of epigastric discomfort was found having a submucosal tumor lesion at the posterior wall of the gastric antrum by gastric endoscopy. He was referred to the Department of Digestive Medicine in our hospital and was diagnosed with moderately to poorly differentiated adenocarcinoma by a boring biopsy. On abdominal CT scan, invasion into the anterior surface of the pancreas and lymph node metastasis were suspected. Neoadjuvant chemotherapy was employed with a diagnosis of gastric cancer cT4b cN1 cM0 cStage IIIb, and 2 courses of TS-1 + CDDP and 2 courses of TS-1 alone were performed. Following the chemotherapy, the pancreatic invasion was ameliorated and the swollen lymph nodes diminished in size. Thereafter the patient was referred to our department. We performed distal gastrectomy and D2 dissection. Histopathological study showed tumor cells associated with a mucin lake and neighboring ectopic pancreatic tissue and ducts with nuclear atypia. Mucinous carcinoma of the ectopic pancreas was thus diagnosed.
Ectopic pancreatic carcinoma is a rare entity and we often have difficulties in making diagnosis before surgery. By closely examining endoscopic and abdominal CT findings, we have to consider the disease as well as submucosal type gastric cancer and GIST as possible differential diagnosis and to select appropriate and sufficient operative procedures including lymph node dissection.
