Fig. 3.

UV-damage class sebaceous carcinomas show poorer differentiation and more infiltration. MSI sebaceous carcinomas have well-circumscribed edges (a) with moderate to well-developed sebaceous differentiation in the form of sebaceous gland formation (b) and mature, lipid-rich sebocytes (b, inset). UV sebaceous carcinomas have more poorly differentiated features (c), often requiring adipophilin immunostaining to confirm sebocytic origin (d, inset). They frequently have infiltrative features and tumor necrosis (d). Scale bar (a) and (c) 1 mm, (b) and (d) 0.1 mm