A case of malignant melanoma arising in a young patient suffering from human immunodeficiency virus (HIV) infection is reported, along with a review of the literature. The neoplasm was characterized by aggressive clinical behaviour and, histopathologically, by a peculiar retiform pattern of growth with neoplastic cells interspersed among collagen bundles in the dermis without evident fibroplastic stromal reaction. In addition, a complete absence of host inflammatory cell infiltrate was noted. We hypothesize that this unusual histopathological pattern of growth, which has never been reported in this clinical setting, might be associated to HIV disease, immunosuppression and poor clinical outcome.