Incidental cystic pancreatic neuroendocrine neoplasm and differential diagnosis.

Pancreatic neuroendocrine neoplasms (panNENs) are tumors derived from pancreatic precursor cells with neuroendocrine differentiation. They display characteristic biologic, histopathologic, and functional features which define their classification along a spectrum ranging from well-differentiated pancreatic neuroendocrine tumors (panNETs) to poorly differentiated pancreatic neuroendocrine carcinomas (panNECs). We report on an interesting case of a well-differentiated panNET with a large central area of cystic change. This example showcases the diagnostic utility of many widely available imaging modalities. We discuss how CT, MRI/MRCP, PET-CT, and endoscopic ultrasound can help diagnose these neoplasms with greater specificity and provide improved insight for initial staging. We will also discuss some imaging mimics to PanNENs that may be considered while refining our differential.