Magnetic resonance imaging of cystic and endocrine pancreatic neoplasms.

This article describes the appearance of miscellaneous cystic and endocrine neoplasms using magnetic resonance imaging (MRI). Magnetic resonance imaging is a useful diagnostic modality in the assessment of various pancreatic neoplasms. Pancreatic endocrine tumors are moderately low in signal intensity on T1-weighted fat-suppressed images and moderately high in signal intensity on T2-weighted fat-suppressed images and demonstrate homogeneous, ring, or diffuse heterogeneous enhancement on immediate postgadolinium gradient echo images. Cystic pancreatic neoplasms, including intraductal papillary mucinous neoplasm, are well demonstrated and subcategorized according to their characteristic cystic configurations on MRI and MR cholangiopancreatography images. Microcystic serous cystadenomas are demonstrated as a honeycombed appearance on T2-weighted images and have a central stellate scar. Mucinous cystic neoplasms usually appear as multilocular cystic masses, with benign forms of macrocystic tumors possessing uniform thickness septations and malignant forms exhibiting irregular septations and tumor nodules. The presence of tumor stroma, invasion of adjacent tissue, or liver metastases can be assessed by MRI. The connection between the pancreatic duct and the cystic tumor is usually well shown on MR cholangiopancreatography images.