To investigate the clinicopathological features, diagnosis and treatment of anorectal malignant melanoma(ARMM).

From 2011 to 2021, ten cases of ARMM confirmed by pathological examination were analyzed retrospectively. Combined with relevant literature, we discussed the clinical data, pathological features, treatment results, prognosis and summarized the experience of diagnosis and treatment.

Among the 10 patients with ARMM,four were males and 6 were females, with the age ranged from 50 to 79 years old, and the average age of (61.4±7.6) years. The clinical manifestations are diverse and non-specific, but mainly bloody stools. The results of CEA, CA19-9 quantitative detection were normal in all patients before operation. Immunohistochemistry was performed in 9 cases, we mainly tested S-100, HBM, MelanA, Ki-67. S-100 was positive in 9 cases, HBM was positive in 8 cases, MelanA was positive in 4 cases and negative in one case except 4 cases. Ki-67 was positive in 9 cases, of which 5 cases had a positive area > 50%. The 6 cases were submitted to abdominoperineal resection, and 4 cases were submitted to local resection of anorectal tumor. The 5 cases received multimodality therapy after operation, one case was submitted to urethrotomy because of urinary metastasis after operation, and 4 cases did not receive any therapy.The overall survival time of patients in this group was 5.5~108 months, the average time was (30.6±29.5) months, the median survival time was 28 months.

ARMM is a rare and highly malignant tumor with atypical clinical manifestations, which is mainly diagnosed by pathological biopsy,but digital anorectal examination plays an important role in the early detection of ARMM. Abdominoperineal resection is the main surgical method for confirmed patients. Radiotherapy, chemotherapy and immunotherapy can be supplemented.