Dermatophytic Pseudomycetoma of the Scalp.

Dermatophytic pseudomycetoma represents a chronic infection characterized by a tumor-like growth containing dermatophytes arranged as clustered aggregates (grains) within the dermis. In contrast to mycetomas, they lack sinus tracts and are more common in the scalp. We describe a dermatophytic pseudomycetoma arising in the scalp of an 18-year-old African-American woman. Histopathologic examination showed a dense, mixed-cell infiltrate expanding the dermis. Accompanying this infiltrate were numerous grains scattered throughout the dermis. No sinus tracts were identified, but a number of grains were seen in the epidermal surface, admixed with serum crust. Recognition of a dermatophytic infection as a pseudomycetoma on a biopsy is important, as surgery may be required for a successful treatment.