Incidental pancreatic cystic lesions.

INTRODUCTION: Incidental pancreatic cystic lesions (IPCL) are becoming an increasingly frequent clinical entity. Within this review, the differential diagnosis, investigation, and management are discussed.
METHODS: A MEDLINE search was performed for IPCL.
RESULTS: Incidence of IPCL varies from 0.2-0.7%, and 30-47% are premalignant or malignant. Pancreatic pseudocysts (PC), serous cystic neoplasms (SCN), intraductal papillary mucinous neoplasms (IPMN), and mucinous cystic neoplasms (MCN) are the most common pathological entities of IPCL. The use of combined modalities, including clinical characteristics, serum tumor markers, cross-sectional imaging, and endoscopic ultrasound (EUS) with cyst fluid analysis should all be used to establish an accurate preoperative diagnosis if possible. Modern multidetector computed tomography (MDCT) and magnetic resonance pancreatography (MRP) allow detailed characterization of IPCL, including size, septation, calcifications, mural nodules, and communication with main pancreatic duct. The best available cyst fluid markers of mucinous neoplasm are viscosity > or =1.6 and carcinoembryonic antigen >192 ng/ml. Although surgery is indicated for MCN or main or mixed duct IPMN, recent advances in the understanding of the natural history and increasingly accurate preoperative diagnosis allow a nonoperative approach to be undertaken for the majority of IPCL. For those treated nonoperatively, the ideal follow-up has yet to be determined.
CONCLUSIONS: Emerging evidence supports selective nonoperative management for the majority of patients who have IPCL when investigated by a multimodal approach. For those in whom a suspicion of malignancy remains, surgery is indicated.