Fig. 5

Pathological features of the pharyngeal cancer represented by haematoxylin & eosin (HE) and immunohistochemical staining (IHC). Full-thickness heterotypic cells generated within the epithelial layer and partial basement membrane were broken through (a, b, c, d). All the tumour cells were diffusely positive for CK5/6, and the index of Ki-67 was approximately 80% (e, f)