Disseminated histoplasmosis evading detection in an immunocompromised patient.

Histoplasma capsulatum is a pathogenic fungus known to exist across the world, especially in the Ohio and Mississippi River Valleys. While clinicians commonly rely on urine and serum Histoplasma antigen testing for rapid detection of disseminated Histoplasmosis, these diagnostic tests have limitations. We present a case of a patient who initially had negative urine and serum Histoplasma antigen tests and required additional testing with lymph node biopsy and immunodiffusion to establish a diagnosis of histoplasmosis. This case highlights the importance of employing multiple testing methods when there is strong clinical suspicion for Histoplasmosis.