Fig. 2

Sebaceous carcinoma: Sheets of malignant cells are shown invading subcutaneous adipose tissue along with tumor infiltrating lymphocytes (lower right) (a). Malignant epithelial cells with nuclear pleomorphism, coarse chromatin, prominent nucleoli and increased mitotic activity (b). Carcinoma with stromal desmoplasia and tumor necrosis (c). Intracytoplasmic vacuolations suggest sebaceous differentiation (d). Carcinoma exhibiting lymphovascular space invasion (e). Adipophilin immunohistochemistry demonstrating diffuse (f) and characteristic strong membranous staining of the intracytoplasmic lipid vacuoles (g). PD-L1 (22C3, pharm Dx) immunohistochemistry showing positive (high, tumor proportion score > 50%) expression in 100% of tumor cells (h)