Robotic low anterior resection of rectal metastasis from small bowel adenocarcinoma: A case report

A 69-year-old female underwent laparoscopic ileal partial resection for ileal adenocarcinoma. Pathological diagnosis was moderately differentiated tubular adenocarcinoma (UICC 8th; T4N0M0 StageIIB). The patient received adjuvant chemotherapy with modified 5-fluorouracil/leucovorin/oxaliplatin. Fourteen months after surgery, computed tomography revealed a mass in the upper rectum. Colonoscopy detected a submucosal protruding mass and a biopsy specimen showed moderately differentiated tubular adenocarcinoma. Robotic low anterior resection was performed. The tumor was located in the upper rectum and there was no macroscopic invasion or peritoneal dissemination. Pathologically, the tumor was moderately differentiated tubular adenocarcinoma located within the rectal wall with little evidence of a carcinoma component in the mucosal lining. Immunohistochemistry showed the same pattern as the previous ileal adenocarcinoma: negativity for cytokeratin 7 and positivity for cytokeratin 20 and caudal-type homeobox 2. In combination with the rectum showing no abnormalities in colonoscopy performed 15 mo previously, the mass was considered hematogenous metastasis from small bowel adenocarcinoma.