[Neuro-endocrine tumors of the gastrointestinal tract: epidemiology, classification, prognosis, diagnosis and therapeutic modalities].

The neuro-endocrine tumors of the gastrointestinal tract comprise a heterogeneous group of slow-growing malignancies with great differences regarding their localization, tissue of origin and their entopic and ectopic production of hormones. They can be subdivided in carcinoid tumors and endocrine tumors of the pancreas. According to their secreted products they manifest as endocrinological syndromes or as local space-occupying tumors. This review focuses, besides summarizing the available epidemiological data and describing tumor localization and classification, on the differing symptom complexes and the prognosis of the various tumor entities. Furthermore, the value of available diagnostic techniques and the role of different therapeutic modalities like surgery, radiation, biotherapy and cytostatic chemotherapy are discussed.