Pancreatic cystic lesions revisited: morphologic patterns and diagnostic pitfalls in daily practice

The increasing use of cross-sectional imaging has led to more frequent incidental detection of pancreatic cystic lesions, presenting diagnostic challenges for radiologists. These lesions encompass a heterogeneous spectrum ranging from benign cysts to premalignant and malignant neoplasms, often with overlapping imaging features. Accurate imaging-based characterization is therefore essential for risk assessment and clinical management. This review presents a morphology-based approach to pancreatic cystic lesions, emphasizing morphologic imaging patterns as a practical framework for structured interpretation. Key features-including ductal communication, internal architecture, and the presence of mural nodules or solid components-are discussed in relation to their pathologic basis and clinical implications. Representative examples illustrate the characteristic appearances of common cystic neoplasms, including serous cystic neoplasm, mucinous cystic neoplasm, and intraductal papillary mucinous neoplasm, along with their variants. Particular attention is given to diagnostic pitfalls and mimickers, such as cystic degeneration of solid tumors including neuroendocrine tumors, solid pseudopapillary neoplasms, and pancreatic ductal adenocarcinoma, which may closely resemble true cystic lesions but require fundamentally different management. Through illustrative cases, this review highlights the importance of integrating morphologic pattern analysis with enhancement characteristics, ductal anatomy, and ancillary imaging findings. Recognition of these patterns and potential pitfalls is essential for accurate interpretation and clinically meaningful guidance.