Excision biopsy
Section reveals skin with a lesion in the dermis comprised of a basaloid proliferation resembling the hair matrix cells, maturing into structureless eosinophilic cells lacking nuclei called shadow cells. Mixed inflammatory infiltrates with neutrophils, lymphocytes and plasma cells seen. Histiocytic infiltrate with multinucleated cells forms at sites of rupture noted. Focal melanophages are seen.No overt atypia seen. Resection margins are clear of the lesion.
Consistent with Pilomatrixoma. No evidence of malignancy seen.