Figure 2: Sebaceous differentiation observed within the apocrine ductal adenoma. Sebaceous cells are characterized by abundant, clear, and vacuolated cytoplasm and a centrally located nucleus surrounded by basaloid cells in the apocrine ductal adenoma. HE. Bar = 50  m. Inset: a frozen section stained with oil red O revealing the lipid droplets within the cytoplasm of sebaceous cells.