Anorectal Malignant Melanoma: Diagnostic Pitfalls and Prognostic Insights from a Single-Center Retrospective Analysis

Background and Objectives: Anorectal malignant melanoma (ARMM) is a rare and aggressive mucosal melanoma with a poor prognosis. Due to its rarity and nonspecific clinical presentation, diagnosis is often delayed, and prognostic data remain limited. Methods: In this retrospective study, 17 patients diagnosed with ARMM were identified from a cohort of 404 malignant melanoma cases treated at our center; however, only 14 patients with complete clinical and pathological data were included in the final analysis. Demographic, clinical, and histopathological data were collected. Disease stage, treatment modalities, and survival outcomes were analyzed. Event-free survival (EFS) and overall survival (OS) were calculated, and potential prognostic factors were evaluated using univariate and multivariate analyses. Results: The mean age at diagnosis was 58 ± 12 years, and six patients (42.9%) were female. The median follow-up duration was 13.3 months, and the median OS was 12.6 months. Six patients (42.9%) were initially misdiagnosed due to overlapping symptoms with benign anorectal conditions. At presentation, seven patients had localized disease, while six had distant metastases. Univariate analysis identified male sex and liver metastasis as adverse prognostic factors for OS; however, these associations were not statistically significant in multivariate analysis. Conclusions: ARMM is associated with poor survival outcomes, and liver metastasis and male sex may be linked to worse prognosis. Diagnostic delay is common due to nonspecific symptoms and frequent initial misdiagnosis, highlighting the need for increased clinical awareness. Further large-scale studies are warranted to better define prognostic markers and optimize management strategies.