Histoplasmosis and Reticuloendothelial Hyperplasia

In 1905 Darling,¹while engaged in a search for leishmaniasis in the Panama Canal Zone, encountered a case of obscure splenomegaly in a Martinique Negro. Smears and sections of the organs revealed an organism strongly suggestive of the Leishman-Donovan body. Darling recognized certain morphologic characteristics differentiating this organism from the causative agent of kala-azar, but because of its resemblance he felt that this, too, was a protozoan, and he therefore named it "Histoplasma capsulatum." Subsequently he described 2 other cases.²Darling's material was studied in 1912 by da Rocha Lima,³who expressed the opinion that these were instances of fungous infection simulating the epizootic lymphangitis of horses due to Cryptococcus farciminosus (Rivolta). Later⁴Darling was said to have concurred in this impression. No other case reports appeared in the literature until 1926, when Watson and Riley⁵uncovered comparable organic changes in postmortem examination of a