Abstract
An autopsy case of disseminated, miliary-type, composite adenocarcinoma and carcinoid tumor associated with adrenocorticotropic syndrome is discussed. Prostatic origin and functional activity were demonstrated by immunohistochemical techniques. Of interest in this case is that the tumor had the characteristics of amine precursor uptake and decarboxylation (APUD) cells and also kept the antigenicity of its prostatic origin. The APUD system perhaps should be considered as one form of functional differentiation of cells of different origin rather than an exclusive derivative of the neural crest.