Endoscopic ultrasonography of neuroendocrine tumours

Neuroendocrine tumours (NETs) of the upper gastrointestinal tract are mainl y located in the pancreas, stomach or duodenum. The aims of preoperative wo rk-up are the localization of primary tumour(s), determination of local tum our invasion, of lymph node metastases and of the hormones secreted by the tumour. Endoscopic ultrasonography (EUS) offers ideal conditions to localiz e and stage NETs of the foregut. We report our results in localizing and st aging NETs of the foregut in 40 patients examined between 1990 and 1997 by EUS, somatostatin receptor scintigraphy (SRS), computed tomography (CT), ma gnetic resonance imaging (MRI) and transabdominal ultrasound (US). EUS show s the highest sensitivity in localizing insulinomas compared with SRS, US, CT and MRI. US and EUS should be the first-line diagnostics if insulinoma h as been proven by a fasting test. Further diagnostic procedures are unneces sary in most cases, Further diagnostics such as CT or MRI to search for dis tant metastases are necessary in large tumours or local invasive tumours. E US shows the highest accuracy to detect or exclude pancreatic gastrinomas, but fails to detect extrapancreatic gastrinomas in about 50%. The combinati on of EUS and SRS gives additional information. First-line diagnostics in g astrinoma patients should be SRS and CT or MRI. If no metastases are detect ed, EUS should be the next preoperative imaging procedure. In nonfunctional NETs, EUS provides the best information on local tumor invasion and region al lymph node involvement. Copyright (C) 2000 S. Karger AG, Basel.