Oral Histoplasma capsulatum infection in association with HIV infection: a case report.

The fungus Histoplasma capsulatum causes histoplasmosis, the most common endemic respiratory mycosis in the United States. Disseminated histoplasmosis in adults is often associated with immunosuppression, such as occurs in HIV infection. We report a case of oral histoplasmosis in an HIV-seropositive patient who presented with an ulceration on the left tip of the tongue, extending to the floor of the mouth, but was otherwise free of any active systemic disease. Histoplasma capsulatum was shown, by both histopathology and staining with a fluorescent antibody reagent specific for the organism, to be present in the lesion and was deduced to be the causative organism.