[A Case of Late Recurrence of Anal Canal Carcinoma after Surgery, Discovered following the Diagnosis of a Subcutaneous Tumor in the Perineal Region].

We present an 82-year-old male patient who underwent laparoscopic abdominal perineal rectal amputation and D3 lymph node dissection, including left inguinal lymph node dissection for anal canal carcinoma. Left inguinal lymph node metastasis was positive, and pT1bN2aM0, pStage Ⅲa was the final pathological diagnosis. He underwent 8 courses of capecitabine plus oxaliplatin therapy as adjuvant chemotherapy. He was examined without recurrence for 5 years postoperatively. However, he awared a perineal subcutaneous tumor and was transferred to our hospital for further examination and treatment 6 years postoperatively. Recurrence after anal canal carcinoma surgery was diagnosed based on a needle biopsy, and perineal subcutaneous tumor resection was performed. This is a rare case of late postoperative recurrence of anal canal carcinoma, which was detected due to a perineal subcutaneous tumor 6 years after surgery for anal canal carcinoma.