[A Case of Anal Canal Squamous Cell Carcinoma with Extensive Rectal Stricture after Chemoradiotherapy].

A 49-year-old female patient was referred to our obstetrics and gynecology clinic in August 2017 with a chief complaint of vaginal defecation. Internal examination revealed a fistula on the posterior wall of the vagina, and rectal examination revealed an irregular mass on the anterior wall of the anal canal. Colonoscopy revealed an irregular mass spanning the lower rectum and anterior wall of the anal canal. Biopsy revealed squamous cell carcinoma. A diagnosis was made of vaginal invasion by an anal canal squamous cell carcinoma, T4N0M0, Stage ⅢB with no evidence of lymph node or distant metastasis. After laparoscopic colostomy of the sigmoid colon, chemoradiotherapy(CRT)with 5-FU/mitomycin C plus 59.4 Gy/33 Fr was performed. The patient had no local recurrence or distant metastasis 5 years after CRT, and the rectovaginal fistula closed spontaneously. Colostomy closure was not performed due to extensive rectal stenosis.