title: Gastroenteropancreatic neuroendocrine tumors: role of imaging in diagnosis and management.
abstract: Gastroenteropancreatic neuroendocrine tumors (GEP-NETs) are a heterogeneous group of neoplasms that arise from cells of the diffuse neuroendocrine system and are characterized by a wide spectrum of clinical manifestations. All NETs are potentially malignant but differ in their biologic characteristics and the probability of metastatic disease. The pathologic classification of these tumors relies on their proliferation and differentiation. In the past decades, several nomenclatures have been proposed to stratify neuroendocrine tumors, but the World Health Organization classification is the one that is most widely accepted and used. The diagnosis of neuroendocrine tumor relies on clinical manifestation, laboratory parameters, imaging features, and tissue biomarkers in a biopsy specimen. With improved understanding of the natural history and lesion biology, management of GEP-NETs has also evolved. Although surgery remains the only potentially curative therapy for patients with primary GEP-NETs, other available treatments include chemotherapy, interferon, somatostatin analogs, and targeted therapies. Recent improvements in both morphologic and functional imaging methods have contributed immensely to patient care. Morphologic imaging with contrast agent-enhanced multidetector computed tomography and magnetic resonance imaging is most widely used for initial evaluation and staging of disease in these patients, whereas functional imaging techniques are useful both for detection and prognostic evaluation and can change treatment planning.
authors.affiliation: Department of Radiology, Division of Abdominal Imaging and Interventional Radiology, Massachusetts General Hospital, Harvard Medical School, 55 Fruit St, White 270, Boston, MA 02114, USA. dsahani@partners.org
authors.forename: Dushyant V
authors.initials: DV
authors.lastname: Sahani
authors.forename: Pietro A
authors.initials: PA
authors.lastname: Bonaffini
authors.forename: Carlos
authors.initials: C
authors.lastname: Fernández-Del Castillo
authors.forename: Michael A
authors.initials: MA
authors.lastname: Blake
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D005260:Female; D005770:Gastrointestinal Neoplasms / Q000175:diagnosis*; D006801:Humans; D007089:Image Enhancement / Q000379:methods*; D008279:Magnetic Resonance Imaging / Q000639:trends*; D008297:Male; D008875:Middle Aged; D018358:Neuroendocrine Tumors; D010190:Pancreatic Neoplasms / Q000175:diagnosis*; D014057:Tomography, X-Ray Computed / Q000639:trends*