[Anorectal melanoma: Clinical case].

Background: Anorectal melanoma (AM) is a rare and aggressive type of tumor, with varied and inconclusive scientific information. Its preoperative diagnosis is challenging due to its rarity and similarity to other anorectal conditions. It represents only 1.3% of melanomas and affects more women than men. Approximately 20-30% of AM cases are amelanotic, complicating endoscopic detection and leading to misdiagnoses. AM is often confused with hemorrhoids, polyps, and rectal cancer in two thirds of patients due to similar symptoms. The causes and risk factors of AM are not well understood, but they are suspected to differ from cutaneous and ocular melanomas. Diagnosis is performed through biopsy and immunohistochemical staining. Colonoscopy helps to characterize the lesions, and histological examination is crucial for definitive diagnosis.

Clinical case: 50-year-old woman with rectal bleeding and proctalgia. AM was diagnosed through colonoscopy, and transanal resection with hemorrhoidectomy was performed.

Conclusions: Management of AM is complicated by the lack of randomized trials. Resection surgery is the standard treatment, but there is no established protocol. Wide local excision may be an option for limited cases. Further research is needed to improve the management and treatment of AM. Early detection and complete surgical removal are crucial for enhancing survival in these patients.