Blastomyces dermatitidis is an endemic fungus that frequently infects the skin. Herein, we present a case of disseminated blastomycosis initially misdiagnosed as pulmonary sarcoidosis and cutaneous squamous cell carcinoma.
A 64-year-old man from New Brunswick, the eastern part of Canada, was referred to the dermatology department for a painless verrucous plaque (3.5 × 1.5 cm) on the helix of his left ear that evolved over the previous 5 months (Figure 1). Squamous cell carcinoma was suggested by initial biopsy findings, which showed pseudoepitheliomatous hyperplasia. On analysis of specimens from a second biopsy, multiple broad-based budding yeasts compatible with B dermatitidis were disclosed under special staining (Figure 2). The diagnosis of cutaneous blastomycosis was further confirmed by positive fungal cultures.
Auger I, Gagné É, Alain J, Pelletier R. Cutaneous Blastomycosis: A Clue for Reassessing the Recent Diagnosis of Pulmonary Sarcoidosis. Arch Dermatol. 2006;142(6):781-798. doi:10.1001/archderm.142.6.795