Disseminated histoplasmosis diagnosed in a bone marrow sample

Histoplasmosis is a fungal infection caused by a dimorphic fungus Histoplasma capsulatum.¹ Progressive disseminated histoplasmosis (PDH) is an AIDS-defining illness with a high lethality rate if not promptly treated.³ In patients with disseminated disease, culture and pathology are the most sensitive.² The gold standard for the identification of the pathogen is the culture demonstrating the thermal dimorphism of the fungus.³ We present a case of a 52 year old male with HIV-1 infection (CDC-C3) and a recent trip to Brasil, admitted in the ICU with a diagnosis of Pneumocystis jirovecii pneumonia (under co-trimoxazole treatment) and haemophagocytic lymphohistiocytosis. A bone marrow (BM) aspirate was performed and stained May-Grunwald-Giemsa films revealed numerous yeast-like bodies inside and outside macrophages with morphology suggestive of Histoplasma spp (Figure 1, Figure 2). Culture and molecular results (bone marrow PCR) confirmed the microbiological diagnosis- Histoplasma capsulatum.

Figure 1
BM aspirate: numerous yeast-like bodies inside macrophages (arrows) with morphology suggestive of Histoplasma spp.

Figure 2
BM aspirate: yeast-like bodies outside macrophages (arrow) with morphology suggestive of Histoplasma spp.

References

• ¹
  Fakhfakh N, Abdelmlak R, Aissa S, Kallel A, Boudawara Y, Bel Hadj S, et al. Disseminated histoplasmosis diagnosed in the bone marrow of an HIV-infected patient: First case imported in Tunisia. J Mycol Med. 2018;28(1):211-4.
• ²
  Hill Ev, Cavuoti D, Luu Hs, McElvania TeKippe E. The Brief Case: Disseminated Histoplasma capsulatum in a Patient with Newly Diagnosed HIV Infection/AIDS. J Clin Microbiol. 2018;56(Feb (3)):e00905-17.
• ³
  Zanotti P, Chirico C, Gulletta M, Ardighieri L, Casari S, Roldan EQ, et al. Disseminated Histoplasmosis as AIDS-presentation. Case Report and Comprehensive Review of Current Literature. Mediterr J Hematol Infect Dis. 2018;10(1):e2018040.

Publication Dates

• Publication in this collection
  21 Mar 2022
• Date of issue
  Jan-Mar 2022

History

• Received
  11 Sept 2020
• Accepted
  02 Oct 2020
• Published
  04 Dec 2020