[A Case of Simultaneous Recurrence of Colon Cancer at the Drain Placement and Anastomotic Sites Postoperatively].

A woman in her 70s presented to our hospital with abdominal pain and right lower abdominal mass. Colonoscopy revealed circumferential ascending colon cancer. She underwent right hemicolectomy, D3 lymphadenectomy, and ileocolonic functional end-to-end anastomosis. The tumorwas pathologically diagnosed as T4aN1M0, Stage Ⅲa. Nine months afterthe first surgery, tumor marker levels increased, and detailed examination yielded a diagnosis of isolated recurrence at the site of drain removal in the abdominal wall. The tumor was resected without exposure. Four months after the second surgery, the tumor recurred in the abdominal wall. Furthermore, colonoscopy revealed anastomotic recurrence. Both recurrent tumors at the anastomotic site and in the abdominal wall were resected. No more recurrence has been detected to date. In this case, a possible cause of recurrence is implantation of cancer cells. Sufficient consideration should be given to innovations in intraoperative maneuvers and surgical wound protection, among others.