Immunohistochemical studies in endocrine carcinoma of the skin

Twenty-two endocrine carcinomas of the skin were examined immunohistochemically for the presence of several polypeptides and serotonin. Eight tumors contained one or more polypeptides. Occasional cells containing calcitonin were found in several tumors. Rare cells with substance P, somatostatin, and ACTH were present in only one tumor each. None of the patients presented a clinical syndrome associated with any of these polypeptides. Met-enkephalin and serotonin were negative in all tumors. The lack of demonstration of met-enkephalin in these tumors makes their relationship to the Merkel cell uncertain.