Abstract: Objective To investigate the clinicopathologic features and the expression of p53,PCNA and Bcl-2 in tricholemmal carcinoma.Methods Skin lesions were studied with HE staining and immunohistochemical markers for p53,PCNA and Bcl-2(S-P method)in 22 cases of skin tricholemmal carcinoma.Both morphological manifestations and immunohistochemical expression were observed.Results There were 15 female and 7 male cases of tricholemmal carcinoma with the ages of 40-79y,including16cases whose scalp were involved.Positive staining of p53,PCNA and Bcl-2 was found in 72%,100% and 63% of patients,respectively.The positive cells of p53 were diffusely distributed.PCNA-positive cells were increased along with the degree of differentiation.Significant differences of Bcl-2 expression were found among the various degrees of differentiation (P<0.01). Conclusions The lobulated construction and abrupt keratinization are hitological features of tricholemmal carcinoma.Different degrees of expression of p53,PCNA and Bcl-2 might take part in neoplastic development and control.

Key words: Skin neoplasms, Tricholemmal carcinoma, Protein p53, Proliferating cell nuclear antigen