[Oral hairy leukoplakia. A study of 5 cases].

Oral hairy leukoplakia (HL) is a newly described lesion (1984) in human immunodeficiency virus infected patients. Patients with HL show a high probability of developing an acquired immunodeficiency syndrome (AIDS). The results of histopathological, microbiological, immunological and ultrastructural studies in five patients with HL and AIDS are reported. The histopathological exam revealed in all cases acanthosis, parakeratosis, koilocytosis and keratin projections on the surface. Dermis was normal. Herpes type virus were seen in four cases and in one of them papilloma virus was also present in electron microscopic examination. There was immunocytochemical evidence of papilloma virus in one lesion. Candida albicans was found in 5 lesions by culture but only in two ones by periodic acid Schiff stain. Virus cultures for herpes virus were negative. Immunocytochemical search of Langerhans cells (S-100, HLA-DR, OKT4, OKT6) showed nearly absence of these cells in HL lesions. These results favour the viral etiology hypothesis of hairy leukoplakia.