An immunohistochemical study of BCA-225 in various skin cancers

We performed an immunohistochemical study of BCA-225, which is a glycoprotein secreted by the T47D breast carcinoma cell line and recognized by monoclonal antibody BRST-1 (clone name: CU-18), in normal skin and various skin cancers. In normal skin, BCA-225 was positive only in the secretory portion of both eccrine and apocrine glands and in mature cells of the sebaceous gland. We observed 10 cases of squamous cell carcinoma of the skin, 10 cases of basal cell carcinoma without sebaceous differentiation, 3 cases of basal cell carcinoma with sebaceous differentiation, 6 cases of malignant trichilemmoma, 8 cases of eccrine porocarcinoma, 3 cases of ductal carcinoma, 1 case of malignant clear cell hidradenoma, 1 case of apocrine adenocarcinoma, 6 cases of extra-ocular sebaceous carcinoma, 5 cases of extramammary Paget's disease with underlying adenocarcinoma, and 11 cases of extramammary Paget's disease without underlying adenocarcinoma. Most of the cases of sweat gland carcinoma, basal cell carcinoma with sebaceous differentiation, sebaceous carcinoma, and extramammary Paget's disease were positive for BCA-225, while none of the cases of squamous cell carcinoma, basal cell carcinoma without sebaceous differentiation, or malignant trichilemmoma were positive. Based on these findings, we believe that BCA-225 is useful in distinguishing tumors with sweat gland and sebaceous differentiation and extramammary Paget's disease from tumors without such differentiation.