Diagnosing Ring-Enhancing Lesions in the Brain of a Patient With AIDS Without Brain Biopsy: A Case of Central Nervous System Histoplasmoma

We report a case of a Puerto Rican male with advanced AIDS who presented with multiple falls and pancytopenia. Magnetic resonance imaging (MRI) of the brain, as initial workup, revealed 2 ring-enhancing brain lesions. Initial cerebrospinal fluid analysis revealed minimal cells, mildly elevated protein, and no organism seen on gram stain. Due to prohibitive thrombocytopenia, brain biopsy was deferred. He had neither clinical nor radiographic improvement despite empiric therapy for both toxoplasmosis and bacterial abscesses. Indicated by pancytopenia, bone marrow (BM) aspiration was performed. Culture of BM aspirate grew Histoplasma capsulatum. Urine histoplasma antigen was markedly elevated. He was treated with liposomal amphotericin B (LamB) for progressive disseminated histoplasmosis with probable central nervous system involvement. Cerebrospinal fluid histoplasma antigen obtained after 2 months of LamB was detected. After prolonged course of LamB, he took itraconazole. Brain MRI at 7-month follow-up revealed significant improvement from baseline study