[Endocrine tumors of the gastrointestinal and pancreatic systems. Multiple endocrine adenoma from another viewpoint]

The 24 endocrine pancreatic tumors and 14 carcinoids were examined immunohistochemically for cholecystokinin, insulin, gastrin, GIP, glucagon, sercretin, VIP, motilin, neurotensin, pancreatic polypeptide (PP), somatostatin, and ACTH. In 12 tumors of the pancreas more than one peptide-containing cell type was observed. The clinical symptoms showed hypersecretion of only one of the hormones, however. The midgut carcinoids (jejunum, appendix) represented the classical view of the carcinoid as an argentaffin cell tumor secreting 5-hydroxytryptamine. Tumors originating in the foregut (bronchus, stomach, duodenum) and hindgut carcinoids (rectum) were nonargentaffine, containing and secreting various polypeptide hormones. We conclude that light microscopic immunohistochemical methods are useful in distinguishing endocrine from nonendocrine tumors and multihormonal syndromes (MEA) in the classification of predominant hormone-secreting tumors.