title: [Neuroendocrine tumors of the gastrointestinal tract. 1: Clinical aspects].
abstract: Endocrine cells are characterized by common biochemical properties and specific cellular markers. Endocrine tumors, too, differ from other types of tumor in a number of ways. These have to do with the classification, the occurrence of functioning or nonfunctioning forms, benign and malignant courses, solitary or multiple presentation, as well as entopic and ectopic growth forms. The incidence of the gastrointestinal functioning tumors is about 0.5-1.0 per 100,000, the nonfunctioning tumors predominating many times over. The diagnosis of functioning endocrine tumors in the early phases of the disease is based on the biochemical demonstration of substances released into the blood, and the clinical picture is determined not primarily by the size or extent of the tumor, but by the biological effects of the tumor secretions. The clinical symptomatology associated with these tumors is often much more marked than the measurable tumor manifestation.
authors.affiliation: Medizinische Klinik IV, Fakultät für Klinische Medizin der Universität Heidelberg.
authors.forename: M K
authors.initials: MK
authors.lastname: Müller
authors.forename: N
authors.initials: N
authors.lastname: Niederle
authors.forename: M V
authors.initials: MV
authors.lastname: Singer
mesh_terms: D002276:Carcinoid Tumor / Q000175:diagnosis; D003937:Diagnosis, Differential; D004701:Endocrine Gland Neoplasms / Q000145:classification / Q000175:diagnosis*; D005770:Gastrointestinal Neoplasms / Q000145:classification / Q000175:diagnosis*; D006801:Humans
vernacular_title: Neuroendokrine Tumoren des Gastrointestinaltrakts. Teil 1: Klinisches Erscheinungsbild.