Transanal resection of anorectal leiomyosarcoma

Anorectal leiomyosarcoma (AL) is a rare and aggressive malignancy. Although the optimal treatment of AL is unknown, surgical resection with negative margins is the mainstay of management. We describe the case of a 72-year-old woman with metastatic rectal leiomyosarcoma, who initially presented with blood per rectum and worsening constipation. She was found to have a 7 × 7.3 cm mass prolapsing through the anal canal into the perineum without extraluminal extension or pathologic lymph nodes on MRI, with pathology consistent with sarcomatoid carcinoma. Transanal R0 resection was performed. Pathology showed a 6 cm high grade sarcoma consistent with leiomyosarcoma and negative margins. Two years post-resection, the patient was found to have a metastatic flank lesion, for which she underwent surgery. If accessible transanally, radical resection of AL is a valuable approach to treatment. Evidence regarding the best adjuvant treatment strategy is lacking and should be evaluated on a case-by-case basis. Number of similar cases published: 27 articles published with 51 cases of anorectal sarcoma based on a review published in 2019.