Abstract: Objective To investigate the significance of immunostainning for Ber EP4 and EMA in the diagnosis of basal cell carcinoma and squamous cell carcinoma of the skin.Methods Immunohistochemical stainning for Ber EP4 and EMA was performed on 115 cases of basal cell carcinoma,squamous cell carcinoma,Bowen's disease,actinic keratosis,basosquamous cell carcinoma,seborrheic keratosis,and verruca vulgaris.Specimens were taken from neoplastic tissues as well as the surrounding skin and appendages.Results Ber EP4 was positively stained in all cases of basal cell carcinoma and basosquamous cell carcinoma,but negatively stained in squamous cell carcinoma,Bowen's disease,actinic keratosis,seborrheic keratosis and verruca vulgaris.Expression of EMA was found in most cases of squamous cell carcinoma and Bowen's disease,and a few cases of actinic keratosis,and in none of basal cell carcinoma,basosquamous cell carcinoma,seborrheic keratosis and verruca vulgaris.Conclusions Routine immunohistochemical staining with both Ber EP4 and EMA is helpful for distinction of skin basal cell carcinoma,squamous cell carcinoma,precancerosis and benign hyperplastic dermatoses.

Key words: Keratosis, Carcinoma,basal cell, Carcinoma,squamous cell, Ber EP4, EMA, Carcinoma,basosquamous