Differential Diagnosis of Cystic Pancreatic Lesions Including the Usefulness of Biomarkers

Background: Cystic pancreatic lesions are more and more often found. Malignant risk ranges from nil to more than 60%. A precise diagnosis is required to adapt surveillance or therapeutic strategy. Methods: We tried to identify the most difficult differential diagnoses encountered in a tertiary center of pancreatology and to guide the reader as how to reach the correct strategy and diagnosis in these situations. Results: We identified eight clinically difficult situations: i) chronic pancreatitis versus intraductal papillary mucinous neoplasms, ii) serous versus mucinous cystic neoplasms, iii) serous cystic neoplasms versus branch-duct intraductal papillary mucinous neoplasms, iv) intraductal papillary mucinous neoplasms versus acinar cell cystadenoma, v) (pseudo-)solid serous cystic neoplasm versus neuroendocrine tumor, vi) pancreatic neuroendocrine tumors versus solid pseudopapillary tumors, vii) cystic forms of a solid tumor, and viii) rare pancreatic or peripancreatic cystic lesions. The work-up should rely on computed tomography scan, pancreatic magnetic resonance imaging, and, only if necessary, endoscopic ultrasound with or without fine needle aspiration. Conclusion: An expert analysis of imaging data allows a precise diagnosis in most of the cases. Pancreatic resection should no longer be performed in case of diagnostic doubt.