Clinicopathological study of malignant melanoma in a regional cancer center

Abstract

Background: : Malignant melanoma is a tumor of melanocytic origin. Although uncommon in India as compared with the west, its prevalence is increasing.

Objectives: To document the pattern of clinicopathological features of malignant melanoma cases attending in a regional cancer center in eastern India.

Material and methods: The present study was a retrospective study of 182 cases diagnosed histopathologically as malignant melanoma during 2011-2016.

Results: Out of the total cases, 170 (93.4%) were cutaneous and 12 (6.6%) were noncutaneous melanoma. The most common age group was sixth decade with a male predominance. Conventional melanotic melanomas were 176 (96.70%), and only 6 cases (3.30%) were amelanotic melanoma. Among noncutaneous melanomas, 6 were in anorectum, 2 in conjunctiva, and 1 case each in nasal cavity, palate, gingivo-buccal sulcus, and vagina. The acrallentigenous type was the most common variety, and the mixed epithelioid and spindle cell type was the most common histopathological pattern. Clark's level III was the most common level of invasion.

Conclusion: The lower extremity is the most common site for melanoma, whereas extracutaneous melanomas are exceedingly rare and aggressive neoplasms. Melanoma can metastasize to regional lymph nodes, however, visceral metastasis to liver can also occur. In the absence of pigment in amelanotic melanoma, immunohistochemical markers such as HMB 45 can be used for definitive diagnosis.

Keywords: Amelanotic malignant melanoma; HMB45; cutaneous melanoma; oral mucosa; vagina.