Differentiation between gastrointestinal neuroendocrine tumors and pancreatic neuroendocrine tumors

Abstract

Gastrointestinal and pancreatic neuroendocrine tumors (GEP-NETs) are mainly derived from the neuroendocrine cells of the gastrointestinal-pancreatic system, which express cell type-specific peptide hormones and general markers (synaptic vesicle proteins and chromogranin A). GEP-NETs have the following characteristics: they are rarely seen in the clinical setting; the tumor sizes are usually small (＜1 cm); tumors grow slowly (for months or years), with several stages of development, and they probably have no symptoms for years; metastases often occur before onset of symptoms, with the liver and bones commonly affected, and the tumor sizes are larger than 2 cm at this time. Thus, GEP-NETs are often misdiagnosed; the diagnostic process is complex, not only relying on clinical manifestations, but also advanced laboratory and scanning means. Moreover, gastrointestinal NETs and pancreatic NETs differ in clinical manifestations, diagnosis, and treatment, and clinicians need to pay more attention to differentiation between them.