Anorectal melanoma in northern Pakistan

Melanoma of the anorectum is a rare malignancy. At Armed Forces Institute of Pathology (AFIP), 11 cases were diagnosed over a 10 year period (1981-1990) constituting 14.2% of all primary malignant melanomas. The anorectum was the commonest site for noncutaneous melanomas (45.8%). The age group commonly affected was the fifth to seventh decade (72.7%). Most of the tumours were extensive involving both anal canal and rectum. The proportion of anorectal melanoma is much higher in our study as compared to western reports (0.4-1.6%). The distribution of noncutaneous melanomas in our population also differs, with a relatively lower proportion of ocular melanomas (33.3%) which are the commonest (80%) in western studies (JPMA 42: 155, 1992).