Imaging of neuroendocrine tumors.

Neuroendocrine tumors may arise from a wide range of organs and may occur in various locations in the body. They include carcinoid tumors, paragangliomas (pheochromocytomas), medullary thyroid carcinomas, and islet cell tumors of the pancreas. In this article the authors focus on the more common tumors with origins primarily in the abdomen, namely carcinoid, paraganglioma, and pancreatic islet cell tumors. Imaging assists in delineating the sites and extent of disease, in preoperative planning for resection of the primary tumor and metastatic disease, and in follow-up. Discussion is restricted to the main imaging modalities used in these tumors: cross-sectional imaging, namely CT and MRI, and nuclear medicine studies.