2006 Volume 67 Issue 9 Pages 2127-2131
The patient was a 61-year-old man who had undergone sigmoidectomy, partial hepatectomy and cholecystectomy for sigmoid colon cancer with liver metastasis and cholelithiasis at the age of 60. Five months after the surgery, he was admitted to another hospital because of a ten-years history of recurrent anal pain. He was performed incision and drainage with a diagnosis of a perianal abscess. Pathological study of pus discharged from the abscess showed adenocarcinoma, and so he was referred to our hospital. At the left side of the anus, we found a tumor 5cm in diameter which was flare and swelling with an irregular skin ulcer. We diagnosed the case as metastatic carcinoma in an anal fistula caused by implantation from sigmoid colon cancer, and conducted abdominoperineal resection including the flare part of circumanal skin. The defect of skin in the anal region was repaired using a gluteus maximus muscle. The perianal tumor showed the same histological appearance as the sigmoid colon cancer. We concluded that free tumor cells from the sigmoid colon cancer might have been implanted in the anal fistula. Since metastasis of sigmoid colon cancer to an anal fistula is relatively rare, we report this case with some bibliographical comments.
Nihon Rinsho Geka Gakkai Zasshi (Journal of Japan Surgical Association)
