Wide local excision could be considered as the initial treatment of primary anorectal malignant melanoma

Anorectal malignant melanoma was a rare disease with extremely poor prognosis. The aim of this study was to explore the clinical characteristic, diagnosis and treatment strategies of anorectal malignant melanoma.

The data of 57 patients with anorectal malignant melanoma was collected and retrospectively analyzed.

Rectal bleeding and anal mass were found to be common symptoms of anorectal malignant melanoma. The preoperative diagnosis rate of anorectal malignant melanoma was 48.6%. The overall 3-year and 5-year survival rate was 38.0% and 21.3% respectively. The 3-year survival rates of stage I and II patients were 63.0% and 16.7% respectively (P = 0.000), and the 5-year survival rates were 33.3% and 11.1% (P = 0.001), which both had significant statistic differences. The 3-year survival rate of patients undergone abdmoninoperineal resection and patients undergone wide local excision were 36.7% and 53.0% respectively (P = 0.280), while the 5-year survival rate were 24.1% and 23.1% (P = 0.642), which both had no significant statistic differences.

This study identified no survival advantage to abdominoperineal resection in treatment of anorectal malignant melanoma, and we propose that wide local excision could be considered as the initial treatment of choice.