ABSTRACT
Objective: This study aims to report the case of a 69-year-old female patient with a diagnosis of anorectal melanoma (AM) established by immunohistochemistry. Methods: Clinical case report, a descriptive and qualitative study. Results: The patient had a nodular and ulcerative lesion in the anal region, the imaging exams revealed an expansive lesion that affected the rectum and the vaginal wall. The chosen course of treatment was initial surgical intervention, the surgery and postoperative course progressed without complications, and the anatomopathological examination confirmed the diagnosis of invasive malignant melanoma of the distal rectum of anorectal transition. The anatomopathological examination confirmed the diagnosis of invasive malignant melanoma located in the distal rectum of the anorectal transition. Immunohistochemistry analysis showed infiltrative melanoma with microsatellites, as well as peri and intratumoral lymphocytic infiltrate, angiolymphatic invasion, and perineural invasion. The surgical resection margins, ovaries, posterior vaginal wall, and parametrium showed no signs of neoplastic involvement. Following the surgery, the patient began immunotherapy, which she is still undergoing. Conclusions: The survival rate of AM can be improved through various diagnostic and therapeutic modalities. However, further exploration of this topic through clinical studies is necessary to enhance both diagnosis and treatment. (AU)