The neural ectodermal origin of the peptide-secreting endocrine glands. A unifying concept for the etiology of multiple endocrine adenomatosis and the inappropriate secretion of peptide hormones by nonendocrine tumors.

Adenoma, Islet Cell/etiology Bile Ducts Bronchi Carcinoid Tumor/etiology Cell Differentiation Cell Movement Chromaffin System/cytology Digestive System/embryology Duodenum Ectoderm Endocrine Glands/embryology,growth & development,metabolism Hormones, Ectopic/metabolism Hypothalamus/cytology,metabolism Intestinal Mucosa/cytology Multiple Endocrine Neoplasia/etiology Neoplasms/etiology,physiopathology Neurons Pancreatic Ducts Peptides/metabolism Pituitary Hormones, Posterior Salivary Glands Serotonin/metabolism Stomach Urogenital System

Hormones, Ectopic Peptides Pituitary Hormones, Posterior Serotonin