Abstract: Objective To observe the expression of 7 cytokeratins in skin epithelial tumors and to assess their diagnostic value.Methods The expression of 7 cytokeratins,including cytokeratin 7(K72.2),cytokeratin 8(C-51),cytokeratin 10(DE-K10),cytokeratin 14(LL002),cytokeratin 17(E3),cytokeratin 18(DC10)and cytokeratin 19(KS19.1),was assessed by immunohistochemical staining (S-P method) in 54 cases of different skin epithelial tumors and 20 normal skin specimens.Results Of 54 cases studied,10 were squmous cell carcinoma (SCC),10 basal cell carcinoma (BCC),19 hair follicle tumor,2 sebaceous carcinoma,and 13 sweat gland tumor.The expression patterns and distribution of the 7 cytokeratins were different in different skin epithelial tumors.Most of the tumor cells stained diffusely for cytokeratins in SCC,BCC and hair follicle tumor;different cytokeratins expressed in different parts of each of the subtypes of sweat gland tumors.Conclusions Analysis of a selected group of cytokeratins may be helpful in the diagnosis and differential diagnosis of SCC,basal cell carcinoma and skin adenexal tumor.

Key words: Keratins, Neoplasms, Immunohistochemistry, Reagent kits,diagnostic