Heterogeneity of expression of cytokeratin subtypes in squamous cell carcinoma of the lung: with special reference to CK14 overexpression in cancer of high-proliferative and lymphogenous metastatic potential.

In surgically resected specimens of squamous cell carcinoma (SCC) of the lung from 45 patients, we immunohistochemically examined the expression of 13 subtypes of cytokeratin (CK), the intermediate filament in cytoplasm of epithelial cells. To investigate heterogeneity of CK, its expression was compared among tumor cell nests with or without keratinization and stratification. Furthermore, the relationship between CK expression and Ki-67 labeling index or p53 expression was investigated.