[A case of ectopic pancreatic cancer in the mesentery of the jejunum].

We report a rare case of ectopic pancreatic cancer in the mesentery of the jejunum. A 68-year-old man presented with left abdominal pain. Contrast-enhanced abdominal CT revealed a 3-cm tumor in the mesentery near the ligament of Treitz. He had required surgery for gastric cancer 28 years ago;therefore, surgery was scheduled on the suspicion of recurrence/metastasis of gastric cancer or gastrointestinal stromal tumor (GIST) and mesenteric tumors. A tumor was observed in the mesentery of the jejunum of the ligament of Treitz. Histopathology showed a moderately differentiated adenocarcinoma, and it was diagnosed as a primary ductal pancreatic cancer (Heinrich classification, not classifiable).