Fig. 3

Histopathology: A widening gap between the collagen fibers in the dermis, along with the presence of diffuse mucin deposition. Additionally, abnormal cells with atypical morphology were observed infiltrating the dermis (A HE× 100, B HE× 200). Immunohistochemical: CK (+) (C), CK7(+) (D), TTF-1(+) (E), Napsin A (+) (F), Ki-67(40%+) (G)