Endoscopic Mucosal Resection of Primary Anorectal Malignant Melanoma: A Case Report

Anorectal melanoma is a rare malignant tumor with a poor prognosis. However, several studies have reported cases of long-term survival. In this report, we present a patient with anorectal melanoma who has survived for 9 years after endoscopic mucosal resection. An 85-year-old man was referred to our hospital for further examination and treatment of an anal tumor 2cm in size. Endoscopic ultrasonography revealed that the depth of tumor invasion was confined to the submucosal layer. Endoscopic mucosal resection was performed, and the tumor was diagnosed as a malignant melanoma. The patient was followed without any additional treatment, which was per his wishes. Although melanoma recurred 4 times thereafter, endoscopic mucosal resection was performed for each recurrent lesion. Thus, he has been alive for 9 years since the first endoscopic mucosal resection without distant metastases. If the depth of tumor invasion is shallow, endoscopic mucosal resection is a useful option among other therapeutic modalities.