Histoplasmosis – low magnification
Granuloma formation in the dermis with a mixed infiltrate of neutrophils, lymphocytes, histiocytes, and giant cells
Ulceration of the epidermis is often present (absent in this case)
Histoplasmosis – high magnification
LEGEND
In comparison, in leishmaniasis (2–3 microns), the organisms are located in the cytoplasm of histiocytes, but typically at the periphery (“marquee sign”)
Multiple spores (2–4 microns), sometimes surrounded by a clear space (pseudocapsule), are found in the cytoplasm of histiocytes
Histoplasmosis
The Grocott stain allows for clear visualization of the spores in black
