Abstract
A solitary duodenal metastasis of colon cancer is very rarely a site of recurrence. A 73-year-old woman underwent sigmoidectomy for sigmoid colon cancer in 2007. Macroscopically, the tumor was type 2, and 40×30 mm in size. Histopathological examination revealed tubular adenocarcinoma (se, n3, ly3, v2, p1, stage IV). She received fluorouracil and irinotecan hydrochlorede-based adjuvant chemotherapies for 10 months. Forty-six months after the operation, she presented with nausea. Enhanced computed tomography (CT) demonstrated a type 2 tumor with stenosis in the third and fourth portions of the duodenum, leading to a diagnosis of moderately differentiated tubular adenocarcinoma. She underwent segmental resection of the duodenum. The histological examination revealed that the tumor was moderately differentiated tubular adenocarcinoma similar to the pathological findings of the previous colon cancer, with tumor cells invading the muscular layer from the serous membrane side. The definitive diagnosis was a solitary peritoneal metastatic tumor from sigmoid colon cancer.
