Phaeohyphomycotic cyst of the skin caused by Exophiala jeanselmei.

A dermosubcutaneous nodule presenting with a superficial papular vascular component occurred in a man receiving long-term prednisone therapy. The histologic findings were characteristic of a phaeohyphomycotic cyst, and a black mold, Exophiala jeanselmei, was isolated. Despite treatment with ketoconazole and local heat, the lesion persisted and was excised. The fungus could be seen in the excised tissue, but cultures were sterile. Subcutaneous phaeohyphomycosis is a relatively uncommon, but recently more frequently recognized type of opportunistic fungus infection.