Relapse of Rectal Cancer in an Anal Fistula: A Rare Case

Background: Colorectal cancer is the second most common cause of cancer-related death worldwide. It is well-known that metasta sis to the liver and lung and local recurrences can occur. Additionally, colorectal cancer occasionally metastasizes to other sites. Only a few reports of such metastases have been published and no definitive therapeutic strategies have been proposed for them. Case Report: The case of a 77-year-old man who was diagnosed with rectal cancer is presented. Eighteen months after curative laparoscopic low anterior resection and D3 lymph node resection, an anal fistula metastasis was diagnosed by computed tomography and biopsy. After administering radiotherapy, percutaneous excision of the lesion. was performed. At 21 months from the surgery, the patient is healthy and no recurrence has been found. Conclusion: Metachronous metastasis of a colorectal cancer to an anal fistula is rare. Careful investigation and optimal treatment can result in a disease-free status.