Cerebral Abscess Caused by Histoplasma capsulatum in an Immunocompetent Patient: A Case Report.

Central nervous system (CNS) histoplasmosis is a rare manifestation of Histoplasma capsulatum infection and is typically associated with disseminated disease in immunocompromised individuals. However, isolated CNS involvement in immunocompetent patients remains uncommon and poses a diagnostic challenge due to its nonspecific clinical presentation. We report the case of a 44-year-old immunocompetent male patient with a history of intravenous drug use who presented with seizures and progressive headache. Brain imaging revealed a left frontal ring-enhancing lesion with midline shift and surrounding edema. Despite negative systemic workup and serologies, the patient underwent surgical drainage of the abscess, and histopathological analysis confirmed infection by H. capsulatum. He was treated with liposomal amphotericin B for 50 days, resulting in full clinical recovery without neurological deficits. This case highlights the importance of including histoplasmosis in the differential diagnosis of cerebral abscesses, even in immunocompetent individuals from endemic areas, especially when noninvasive diagnostics are inconclusive. Early surgical intervention combined with appropriate antifungal therapy can lead to excellent outcomes.