Metachronous colonic metastasis from pancreatic cancer seven years post-pancreatoduodenectomy

Colonic metastasis from other organs is very rare. Here we report the case of a 62-year-old man with a history of pancreatoduodenectomy for stage IIB pancreatic head cancer performed seven years back. He presented with abdominal distension and pain. Under the preoperative diagnosis of bowel obstruction, surgical treatment was performed, and a circumferential lesion causing bowel obstruction of the ascending colon was detected. A right hemicolectomy with lymph node dissection was performed. The specimen showed a 5-cm wall thickening with a cobble-stone like appearance of the ascending colon, which morphologically appeared scirrhous. Histological examination revealed cancer nests invading from the subserosa to the muscular and submucosal layers of the colon. Immunohistochemical analysis of the tumor cells demonstrated positive staining for cytokeratin 7, but negative for cytokeratin 20, which was the same as the previous pancreatic cancer specimen. These pathological and immunohistochemical features strongly supported the diagnosis of colonic metastasis from the pancreas. Thereafter, the patient received systemic chemotherapy, but unfortunately, he died 14 mo after the surgery.