[A case of adenocarcinoma occurring at colostomy site 7 years after abdominoperineal resection for rectal cancer resected after preoperative mFOLFOX6 chemotherapy].

A 78-year-old man had undergone abdominoperineal resection for rectal cancer in 2003. After 7 years, he visited our hospital with complaints of turbid discharge from the stoma. A tumor 11 cm in diameter was shown at the site of the stoma. A partial resected biopsy revealed moderately-differentiated adenocarcinoma. We diagnosed metachronous multiple carcinoma or recurrent cancer at the colostomy site. After loop colostomy of the ascending colon was performed, systemic chemotherapy with mFOLFOX6 was performed. After 5 courses, the tumor revealed a significant reduction in its size. Afterwards, the stoma including the tumor and remaining left-side colon with adjacent abdominal wall was resected, keeping the surgical margin free. In the resected specimen, histological evaluation of the treatment with chemotherapy was assessed to be Grade 1a. As a result of preoperative chemotherapy, we finally were able to resect the minimal area of the adjacent skin and abdominal wall, and succeed in primary closure of the surgical wound. This case suggests that preoperative chemotherapy is a good option for treating cancer occurring at a colostomy site.