Histologic examination with specific stains (Grocott methenamine–silver) revealed granulomatous inflammation of the dermis and many septate hyphae, some of which were branched, and large, round fungal cells. When observed in detail, some of the round fungal cells showed an optically empty central space, whereas others stained evenly. Culture on Sabouraud dextrose agar without cycloheximide yielded a radiating, pale-brown, cottony colony, characteristic of A alternata. The colony grew in 4 to 5 days and later became intensely phaeoid, characterized microscopically by brown dictyospores with short beaks, arranged in chains typical of the species.
Verrucoid Lesions of the Right Hand and Wrist. Arch Dermatol. 2001;137(6):815-820. doi: