Histoplasmosis Disguised as Pyrexia of Unknown Origin in Kidney Transplant Recipients: Bone Marrow Biopsy was Key to Diagnosis

Immunocompromised host commonly develops a disseminated form of histoplasmosis and may have diverse manifestations. We present a case of histoplasmosis in a kidney transplant recipient who presented with pyrexia of unknown origin and pancytopenia. Bronchoalveolar lavage fluid analysis and serum antigen were negative for histoplasmosis. Bone marrow biopsy showed periodic acid-Schiff-positive intra and extracellular yeast-like organisms and later confirmed as Histoplasma capsulatum. The patient was successfully treated with intravenous liposomal amphotericin B, followed by oral itraconazole. Thus, bone marrow examination proved as key to diagnosis in our case.