Natural history of neuroendocrine enteropancreatic tumors

Neuroendocrine enteropancreatic tumors (NEEPTs) include tumors developing f rom the pancreatic islets and the duodenal loop, and those developing from gut serotonin-secreting cells (mid-gut carcinoids). When functioning, they are rare tumors with frequently inconsistant clinical and biological charac teristics. Provocative dynamic tests are very useful. Their natural history , with the exception of insulinomas and mid-gut carcinoids, is still incomp letely known due to their rarity, relatively recent description, slow evolu tion and the absence of definitive reliable markers for prognosis. The foll owing factors affect the natural history of NEEPTs. (1) Inclusion or not wi thin the spectrum of multiple endocrine neoplasia type-1 (MEN1), such an in tegration often dramatically modifies the management strategy. In patients with MEN1, NEEPTs are often multiple, diffusely spread in the duodenopancre atic area and of small size. Definite cure by surgery is then very scarce. Mid-gut carcinoid tumors are the most protean NEEPTs. In contrast to append iceal carcinoids, usually with a benign course, mid-gut carcinoids have a m ore malignant course and are very common indeed: local transmural invasion, early metastasis to lymph nodes and/or liver, and symptoms from hormone ov ersecretion. Carcinoid syndrome is usually well controlled by long-acting s omatostatin analogs. (2) Disease spreading, i.e. liver and bone metastases, are the major causes of death in patients with NEEPTs. Liver metastases (L Ms) are synchronous in about 75% of the patients with LMs but may develop d uring follow-up (about 25% of the patients with LMs were without LMs at the initial evaluation). Development of bone metastases has a very poor progno sis accompanying LM progression. Copyright (C) 2000 S. Karger AG, Basel.