Pancreatic resections for cystic neoplasms: from the surgeon's presumption to the pathologist's reality

Current guidelines for the management of pancreatic cystic neoplasms are based on the assumption that these lesions can be classified correctly on the basis of features of cross-sectional imaging. However, a certain degree of overlap between different lesions exists, and little is known about the rate of inaccurate preoperative diagnoses. To address this issue, preoperative and final pathologic diagnoses of patients resected for a presumed pancreatic cystic neoplasm were compared.

Retrospective analysis was undertaken of patients managed operatively between 2000 and 2010. Preoperative workup was reviewed to identify diagnostic pitfalls and potential risk factors for incorrect preoperative characterization of cystic lesions presumed to be neoplastic.

We analyzed 476 patients. Final pathologic diagnosis matched the preoperative diagnosis in 78% of cases. The highest accuracy was reached for solid pseudopapillary neoplasms (95%) and for main duct/mixed duct intraductal papillary mucinous neoplasms (81%). Surprisingly, 23 cysts (5%) were found to be ductal adenocarcinoma, whereas 45 patients (9%) underwent a pancreatic resection for a non-neoplastic condition. The use of a routine radiologic workup, including contrast-enhanced ultrasonography and magnetic resonance imaging, was associated with a favorably correct characterization of the cystic lesion. Endoscopic ultrasonography did not seem to improve diagnostic accuracy. Increased levels of serum carbohydrate antigen (CA)19-9 resulted as risk factors for an incorrect diagnosis as well as for a final diagnosis of a ductal adenocarcinoma.

The overall rate of inaccurate preoperative diagnoses in a tertiary care center with a broad experience in pancreatology approached 22%. Serum CA19-9 is an important complementary tool within the context of preoperative investigation of cystic neoplasms of the pancreas.