Islet Cell Tumors of the Pancreas: A Variety of Multiphase Dynamic Imaging Findings with Pathologic Correlations Focusing on Nonfunctioning Tumors and Insulinomas

docrine tumor that is clinically classified as functioning or nonfunctioning based on its ability to produce hormones. From a pathologist’s viewpoint, however, ICTs are indistinguishable from each other (1, 2). The prompt identification and early treatment of ICTs is of importance because it has been shown to improve the prognosis and life expectancy more than other pancreatic malignancies (3). The most common and classic findings of functioning ICTs on dynamic computed tomography (CT) are hyperattenuating small lesions (50% of them are less than 1.3 cm) in the arterial phase, which later become inconspicuous in the venous phase (3). Up to 70% of nonfunctioning ICTs also have similar characteristics consistent with arterial enhancements (2, 3). Yet, they are usually larger and more necrotic than functioning ICTs or other pancreatic tumors with or without cystic or calcified components (1, 3). So, nonfunctioning ICTs are not easily distinguishable from other solid or cystic pancreatic tumors, which have different prognoses and need different therapeutic approaches (2, 3). In this article, we presented six pancreatic ICTs (two insuliomas and four nonfunctioning tumors), and illustrated a spectrum of enhancement patterns of the lesions in relation with their histopathologic characteristics.