HE staining showed a typical hyperplasia after 6 weeks of DMBA smearing, and most hamsters appeared characters of squamous cell carcinoma after 12 weeks of DMBA smearing.

• HE染色证实，从涂药的第6周开始粘膜出现不典型增生，至第12周时，大部分地鼠颊囊均已出现鳞状细胞癌的组织表现。