Fig. 5

Macroscopic and pathological findings. a Macroscopic analysis showing relatively clear boundaries. A localized yellowish, white mass was observed, and continuity between the skin and papilla was not evident. b Histopathological analysis revealed carcinoma in situ as the dominant lesion. Hematoxylin and eosin staining revealed cytoplasmic clear and minute vacuolar structures of numerous tumor cells, indicating sebaceous differentiation. c Higher magnification of b. d Most tumor cells (50–90%) were adipophilin-positive. e Higher magnification of d. f–i Tumor cells did not detectably express estrogen receptor (ER), f progesterone receptor (PgR) (h), or human epidermal receptor 2 (HER2) (i). g Higher magnification of f. j The Ki 67 labeling index was 32.4%