Year: 2004
Type: letter
Abstract: Sir—Although the image of the skin biopsy specimen in the recent photo quiz by Hasse and Kronenberg [1] may represent infection with Histoplasma capsulatum var. duboisii, it does not prove the diagnosis. The fungus was apparently not cultured, and the photomicrograph of the organisms shows nothing specifically diagnostic of H. capsulatum var. duboisii. The photomicrograph of the skin specimen stained with periodic acid-Schiff stain reveals clusters of yeast that appear more round than oval and do not show the “hour-glass” or “figure eight” budding forms typical of H. capsulatum var. duboisii [2]. Chain formation and bud scars are 2 other features of this organism (figure 1); neither is demonstrated in the image provided by Hasse and Kronenberg [1]. Photomicrographs of specimens from a lytic lesion of the right tibia demonstrating Histoplasma capsulatum var. duboisii. Left, periodic acid-Schiff staining reveals a thick cell wall, vacuolated cytoplasm, and narrow-based bud. Right, Grocott methenamine silver staining demonstrates the classic “hour-glass” shape of H. capsulatum var. duboisii; the parent and daughter cells are of equal size and joined by a narrow base. Cryptococcus neoformans may vary in size by as much as 20 microns, and the capsular-deficient form can appear similar to the image seen in the figure provided by Hasse and Kronenberg [1]; a positive reaction with mucicarmine stain would be diagnostic. Blastomyces dermatitis is a similar size and also has a thick cell wall; diagnosis requires identification of broad-based buds and/or multiple nuclei. Blastomycosis is not likely in a patient from Africa or Europe.
Source: Clinical Infectious Diseases
DOI: 10.1086/381455
Institution: Armed Forces Institute of Pathology
Language: English
Subfield: Infectious Diseases
Field: Medicine
Domain: Health Sciences
Open Access status: hybrid
Estimated APC paid: $4,763
OpenAlex ID: W2100539239