Organ preservation in anorectal melanoma: A tempting challenge—a case report

Abstract

Melanoma arising from melanocytes is an uncommon neoplastic lesion, with rare occurrences in anorectal mucosa. While mucosal melanomas constitute a small portion of all melanomas, anorectal cases are even rarer and present with aggressive behavior and poor prognosis. Surgical management is central, with evolving debates regarding optimal approaches. We present a case of a 60-year-old woman with anorectal melanoma. She complained of rectal bleeding and weight loss. Clinical examination and pelvic magnetic resonance imaging revealed a 3-cm budding lesion on the anterior rectal wall. Colonoscopy identified a pedunculated anorectal tumor of 3 cm, situated 4 cm from the anal margin. A biopsy led us to a malignant lesion: anorectal melanoma. Pelvic imaging displayed a localized tumor, prompting wide local excision with millimetric negative margins. These resection margins were estimated insufficient, even in front of R0 resection. Thus, and after multidisciplinary discussion, we opted for abdominoperineal resection after wide local excision. Lymph nodes were biopsied, confirming no residual tumor. Follow-up exhibited no recurrence at 1 year. Our case emphasizes the pivotal role of surgical strategy in managing anorectal melanoma, challenging the paradigm of organ preservation. Despite therapeutic progress, surgery remains integral, contributing to improved outcomes and addressing the metastatic potential inherent to this disease.