Immunohistochemical Study of Skin Epithelial Tumors Using Anti-CEA Antibodies : Significance of Presence of CEA in the Skin Tissues

To investigate diagnostic value of carcinombryonic antigen (CEA) staining in sweat gland tumors, the normal skin and several kinds of epithelial skin tumors were immunohistochemically examined by the immunoperoxidase technique using polyclonal anti-CEA antibodies (PCEA) and monoclonal anti-CEA antibody (MCEA). In the normal skin tissue, the secretory cells, ductal cells, duct cuticle and luminal materials of either eccrine glands or apocrine glands showed PCEA-positive reactions. None of the other skin components showed positive reactions to the PCEA. A weak MCEA-positive reaction was seen only in the dermal and intraepidermal portions of the sweat gland ducts. In the skin tumors, PCEA positive reactions were found in all the cases of extramammary Paget's disease and sweat gland tumors. In all the cases of the squamous cell carcinoma and Bowen's disease, the keratotic parts showed PCEA-positive reactions. These reactions became very weak or negative, when stained with MCEA. Most of the PCEA-positive materials in the skin tissues may be different from the original CEA. Although PCEA is still thought to be important as an immunohistochemical marker for the diagnosis of sweat gland tumors, there may be a heterogeneity of PCEA-reacting substances among normal skin and tumor tissues