Evaluation and Diagnosis of Pancreatic and Gastrointestinal Neuroendocrine Tumors

Gastroenteropancreatic neuroendocrine tumors are a diverse group of tumors with marked variability in presentation and prognosis. Most pancreatic neuroendocrine tumors are non-functional. These tumors are often identified when evaluating symptoms due to mass effect or are identified incidentally on cross-sectional imaging. Insulinomas, Gastrinomas, Glucagonomas, Somatostatinomas, and VIPomas secrete functional peptides that can present with unique clinical syndromes. Well-differentiated neuroendocrine tumors of the gastrointestinal tract are often referred to as carcinoid tumors and typically only have syndromic presentation after metastatic spread to the liver. Poorly differentiated neuroendocrine tumors are aggressive tumors with early distant spread and a poor prognosis. Locating gastroenteropancreatic neuroendocrine tumors can be challenging and often involves a combination of imaging modalities such as CT, MRI, DOTATATE PET, and endoscopic ultrasound. Efficient initial evaluation and accurate diagnosis is key for management of functional effects of the tumors and possible malignant consequences.