Disseminated genitourinary histoplasmosis in a patient with AIDS with negative urine antigen testing

Disseminated histoplasmosis is a life-threatening condition in immunocompromised patients. The majority of healthy persons have benign disease not requiring treatment. However, in persons living with HIV, mortality is high and accurate diagnosis is paramount. We present a case of a 48-year-old HIV-positive woman who presented with haematuria and flank pain. She had a history of recurrent urinary tract infection and nephrolithiasis with obstructive hydronephrosis. During cystoscopy, a bladder lesion was found. Pathological evaluation demonstrated abundant intracellular organisms with apparent budding. Subsequent urine histoplasma antigen was negative. Given the high index of suspicion for histoplasmosis based on the surgical pathology findings and epidemiological history, the patient was started immediately on antifungal therapy. One week later, PCR results of the bladder lesion confirmed the presence of Histoplasma capsulatum. This case highlights a rare presentation of genitourinary histoplasmosis and the utility of surgical pathology evaluation and PCR for diagnosis.