Disseminated histoplasmosis diagnosed on peripheral blood smear: a case report

Abstract

Abstract Introduction/Objective Histoplasmosis is an infection caused by the inhalation of a dimorphic fungus, Histoplasma capsulatum. H. Capsulatum var capsulatum is the main variety we encounter in the United States and is endemic in the Mississippi river valley. In immunocompetent individuals the infection is usually asymptomatic or presents as flu- like symptoms. Disseminated histoplasmosis is a severe and often fatal opportunistic infection if not treated, usually seen in immunocompromised patients. Methods/Case Report We report a case of a 27-year-old female intra-venous drug user with past medical history of untreated HIV diagnosed in 2018, who is being admitted for suspected necrotizing fasciitis of the vulva. On admission, her complete blood count shows pancytopenia with a white blood cell count of 2.9 × 109/L (NR 4.3-10.8 × 109/L), hemoglobin 6.1 g/dL (NR 12-16 g/dL), and a platelet count of 43 × 109/L (NR 150-400 × 109/L). A peripheral blood smear obtained showing rare neutrophils with intracellular organism highly suggestive of histoplasma capsulatum. CT Chest showing diffuse ground glass opacities and a subsequent cytology from bronchoalveolar lavage performed revealed numerous macrophages filled with ovoid organism surrounded by a cytoplasmic halo, GMS stain highlights the rim consistent with histoplasma capsulatum. Patient expired after one week in the ICU for severe acute respiratory distress syndrome, sepsis, histoplasmosis, strep pneumonia and hepatic failure. Results (if a Case Study enter NA) NA Conclusion Careful examination of Peripheral blood smear along with correct clinical history can aid in early diagnosis of disseminated histoplasmosis.