Oral melanomas in HIV-positive patients: Report of two cases and review of the literature.

Oral melanoma in HIV-positive patients is exceedingly rare, with only two cases reported in the literature published in English. Herein, we report two additional cases of oral melanomas which occurred as oral masses in the upper gingiva and hard palate in 35- and 27-year-old HIV-positive women. Significant thrombocytopenia, anemia, reduced CD4 cells, and high HIV load occurred in both patients. Microscopically, the lesions showed a variable proliferation of fusiform and epithelioid-pigmented cells, with cellular pleomorphism and high mitotic index. The diagnosis of melanoma was supported by positive immunoreactivity for S-100, MelanA, and HMB-45. Both cases had an unfavorable outcome, and the patients died a few months after the initial diagnosis. Because of its rarity, oral melanoma occurring in HIV-positive patients can pose problems in diagnosis and should be clinically distinguished from Kaposi's sarcoma, which is more common in the context of the immunodeficiency syndrome.