Hematoxylin-eosin staining revealed a nonencapsulated nodule involving the entire dermis, with some extension into the subcutis, and an overlying epidermis with moderate pseudoepitheliomatous hyperplasia. The neoplasm was composed of large, plump, polyhedral cells with granular eosinophilic cytoplasm. The cells were clustered as nests, with collagen bundles surrounding some of the clusters. The nuclei were mostly small, round, and centrally located. No mitotic activity or pleomorphism was observed. The cytoplasm contained periodic acid–Schiff (PAS)-positive, diastase-resistant granules and stained strongly positive for S100 protein.
Pruritic Vulvar Nodule in a Black Woman. Arch Dermatol. 2000;136(9):1165-1170. doi: