Immunohistochemical detection of carcinoembryonic antigen and protein S-100 in sweat gland tumors

Carcinoembryonic antigen (CEA) and S 100 protein (S 100) have been demonstrated in formalin-fixed paraffin sections of eccrine and apocrine sweat glands, and tumors of the sweat glands, as well as, for comparison, in a variety of tumors deriving from epidermal and follicular structures using the peroxidase-antiperoxidase technique. CEA is detectable, as a membrane antigen, in the normal coil of eccrine sweat glands and in the cytoplasm of luminal cells in eccrine and apocrine sweat ducts up to the horny layer. Nearly all tumors of the sweat glands contain variable amounts of CEA. S 100 is localized in the cytoplasm of eccrine coils and secreted with the sweat. Apparently it is only found in tumors derived from the eccrine and apocrine sweat gland coils. Immunohistochemical demonstration of CEA and S 100 thus facilitates the diagnosis of tumors of the sweat glands and their differentiation from epidermal and follicular tumors.