ANAL CANAL MELANOMA – REPORT OF TWO CASES, CLINICAL PRESENTATIONS, AND MANAGEMENT

Case Presentation Case 1: Male, 75 years old, with hemorrhoidal disease for 3 years, admitted due to anal pain, bleeding, and anemia. On examination, hardened nodules of 4 cm were noted, sparing the right posterolateral and lateral areas, with areas of bleeding hemorrhoidal thrombosis. A colonoscopy performed 4 months prior showed hemorrhoidal nodules. Upon proctologic examination under anesthesia, a larger lesion than described in the colonoscopy was observed, with hyperpigmented and hypopigmented areas and central anterior-lateral left ulceration. Due to friability and bleeding, resection was performed on the right anterior-lateral and left posterior-lateral areas, preserving a mucosal bridge with an apparent residual lesion. Pathology confirmed ulcerated nodular melanoma with compromised margins in both lesions. Staging with a chest and abdominal CT scan revealed hepatic and pulmonary metastases, and palliative chemotherapy was indicated. Case 2: Female, 72 years old, with a history of breast cutaneous melanoma resection in 2018, presented with persistent anal bleeding and burning, as well as ribbon-like stools. On examination, a vegetating perianal lesion starting about 3 cm from the anal margin, extending cranially by 3 cm, affected 30% of the anal canal and involved the right puborectal sling. Colonoscopy revealed a vegetative, ulcerated lesion extending into the rectum, and biopsy suggested spindle cell neoplasm. Immunohistochemistry confirmed mucosal melanoma after HSL 500 panel. PET-CT showed involvement of mesorectal, para-aortic, and interaortocaval lymph nodes. Radiotherapy and immunotherapy with Ipilimumab and Nivolumab were initiated. On day 30 of treatment, complete regression of the lesion was observed on endoscopic examination, with biopsy of the scar showing proctitis.

Discussion Mucosal anal melanoma is a rare and aggressive condition, often diagnosed late, with 1/3 of patients presenting with metastasis at diagnosis. The diagnostic process should include physical examination, immunohistochemistry, and advanced imaging for staging. The main treatment is surgical excision of the lesion with wide margins, and regional lymphadenectomy may be indicated. Immunotherapy has shown significant benefits in the adjuvant setting, improving disease-free survival in patients with anal mucosal melanoma.

Conclusion Anorectal melanoma has a poor prognosis, and treatment guidelines are not clear. Surgical resection with clear margins controls local disease, and other systemic therapies may improve prognosis.

 

MissingLinkText

Die Autoren geben an, dass kein Interessenkonflikt besteht.

Publikationsverlauf

Artikel online veröffentlicht:
25. April 2025