[A case of anal metastasis from sigmoid colon cancer in a long-term survivor who had repeated local excisions].

A 72-year-old man underwent sigmoidectomy for sigmoid colon cancer in January 1999. Histopathological examination revealed a moderately differentiated adenocarcinoma, tub 2, SS, ly2, v2, N1, H0, P0, M0, Stage IIIa, cur A. In March 2001, he complained of an anal bleeding and underwent colonoscopy. It showed a submucosal tumor 15 mm in diameter at the anal canal and the biopsy indicated a moderately differentiated adenocarcinoma. This tumor was suspected of metastasis from sigmoid colon cancer and transanal resection was performed in May 2001. Histopathological examination revealed a moderately differentiated adenocarcinoma, which was the same histological type as primary sigmoid colon cancer, tub 2, A, ly2, v2, RM0. The diagnosis of anal metastasis was made on the basis of three points. First, tumor was covered with anal epithelium. Secondly, there were severe lymphatic and venous involvements. Thirdly, there were no findings of other primary anal cancer. By removing anal canal metastases twice, inguinal lymph node metastases three times and lung metastases in each time, he survived for 11 years after a primary surgery. We reported here because it was a very interesting and rare case that the patient was cancer-free after surgeries as many as seven times.