Melanocytic activation in HIV-1 disease: HMB-45 staining in common acquired nevi. Military Medical Consortium for the Advancement of Retroviral Research.

Background: An increase in pigmented lesions has been reported in HIV-1-infected patients. In a study of HIV-1-positive patients, we have seen patients who noticed new or changing pigmented lesions.

Objective: The goal of this study was to determine to what degree these pigmented lesions showed evidence of significant melanocytic proliferation as opposed to increased pigment production without significant melanocytic proliferation.

Methods: Biopsy specimens were studied with routine light microscopy and immunohistochemical stains including S-100 protein, HMB-45, and proliferating cell nuclear antigen.

Results: The lesions included two malignant melanomas and 42 benign melanocytic lesions. Significant staining of dermal melanocytes with HMB-45 was present in two of three melanomas and in 19 of 42 nevi. With stains for proliferating cell nuclear antigen there was a positive reaction in the dermal component of both melanomas and a negative reaction in the dermal cells of the nevi.

Conclusion: In some HIV-1-infected patients there is stimulation of melanosome production without significant melanocyte proliferation.