Cystic Lesions of the Pancreas

Background/Aims: Due to enhanced imaging modalities, pancreatic cysts are being increasingly detected, often as an incidental finding. They comprise a wide range of differing underlying pathologies from completely benign through premalignant to frankly malignant. The exact diagnostic and management pathway of these cysts remains problematic and this review attempts to provide an overview of the pathology underlying pancreatic cystic lesions and suggests appropriate methods of management. Methods: A search was undertaken with a Pubmed database to identify all English articles using the keywords ‘pancreatic cysts’, ‘serous cystadenoma’, ‘intraductal papillary mucinous tumour’, ‘pseudocysts’, ‘mucinous cystic neoplasm’ and ‘solid pseudopapillary tumour’. Results: The mainstay of assessment of pancreatic cysts is cross-sectional imaging incorporating CT and MRI. Fine-needle aspiration (FNA) (often with endoscopic ultrasound) may provide valuable additional information but can lack sensitivity. Symptomatic cysts, increasing age and multilocular cysts (with a solid component and thick walls) are predictors of malignancy. A raised cyst aspirate CEA, CA 19-9 and mucin content (including abnormal cytology), if present, can accurately distinguish premalignant and malignant cysts from benign ones. Conclusion: In summary, all patients with pancreatic cystic lesions, whether asymptomatic or symptomatic, must be thoroughly investigated to ascertain the underlying nature of the cyst. Small asymptomatic cysts (<3 cm) with no suspicious features on imaging or FNA may be safely followed up. Follow-up should continue for at least 4 years, with a repeat FNA if needed. An algorithm for the management of pancreatic cystic tumours is also suggested.