Disseminated atypical blastomycosis in two patients with AIDS

Two men with AIDS developed fungal infections and subsequently died as a result of dissemination of the fungal infection. Findings obtained by histologic examination, serological studies, and cultures suggested that the infections were caused by Blastomyces dermatitidis. Tissue sections showed polymorphic yeast-like cells 5-20 microns in diameter (some with broad and others with narrow single- or multiple-based buds), small yeasts, and hyphal elements. The exoantigen K positivity and exoantigen A negativity of one of the isolates indicated that the fungus was more like an African than a North American serotype.