[A Case of Metastatic Carcinoma of Anal Fistula].

A 58-year-old man underwent rectal resection(D2 dissection)for rectal cancer and liver/lung metastases in August 2009. Histopathological findings were Ra, type 2, 70×80mm, tub1>tub2, int, pSI(peritoneum), INF b, ly1, v1, pN1(2/13), pPM0, pDM0, M1a(H1, PUL1), fStage IV . The lung metastasis had disappeared on chest CT after postoperative chemotherapy and we were able to perform radical resection of the liver metastasis by performing hepatectomy twice. In October 2013, anal pain appeared and a painful tumor approximately 2 cm in size was found in the 5 o'clock direction of the anus. Biopsy revealed a well-differentiated tubular adenocarcinoma similar to rectal cancer, and it was diagnosed as a fistula metastasis of rectal cancer.We performed chemoradiotherapy(S-1 120mg/day plus RT 60 Gy/30 Fr)as surgery was recommended but refused. As a result, the tumor reduced markedly in size. In December 2015, the tumor enlarged in size and the patient and family requested surgery. We, therefore, performed abdominoperineal resection. Currently, the patient is alive at 18 months after surgery with no recurrence.