62 year old male with history of renal transplant 3 months ago on tacrolimus, mycophenolate mofetil, prednisone, bactrim and valgancyclovir (CMV IgG positive) presented with persistent fever, malaise and nausea and vomiting. Despite extensive infectious workup and antibiotics, patient continued to have persistent fever and no source was revealed. Hematology was consulted for pancytopenia, ferritin level >100,000ng/mL, splenomegaly, and elevated triglycerides. Clinical diagnosis of hemophagocytic lymphohistiocytosis (HLH) was made. Peripheral smear was unrevealing. A bone marrow was performed for cultures and lymphoproliferative disorder. A bedside smear was made from the aspirate and stained with quickstain and reviewed on the same day. The smear revealed numerous intracytoplasmic small narrow base yeast cells with eccentric nuclei with clear capsule consistent with histoplasma in the bone marrow. Patient clinically improved after being started on intravenous liposomal amphotericin.  Subsequent labs obtained confirmed elevated soluble IL-2R and positive urine histoplasma antigen. 

 We report a case of disseminated histoplasmosis associated HLH, which was initially diagnosed on a bedside smear even before they were stained with Wright-Giemsa for pathology review. Current treatment for HLH is dexamethasone, etoposide and cyclosporine A, which would have been detrimental to an immunocompromised patient with disseminated infection. This highlights the importance of evaluating bedside smears for prompt diagnosis and treatment.