Figure 1. Histologic appearance of the cutaneous lesion of a man with blastomycosis. Ulcerated epidermis (A) showing superficial and deep perivascular infiltrates, predominantly mononuclear inflammatory cells. Fibrinopurulent exudate (B) adjacent to the ulcer, comprising neutrophils, erythrocytes, and necrotic cellular debris (C), and occasional large yeasts morphologically compatible with Blastomyces dermatitidis infection (D and E). Hematoxylin and eosin stain (A, B, and C), Grocott methenamine silver stain (D), and immunoalkaline phosphatase with antibody against B. dermatitidis and naphthol fast red with hematoxylin counterstain (E). Original magnifications ×12.5 (A), ×25 (B), and ×100 (C–E).