[Liquid-based cytology diagnosis of endoscopic ultrasound-guided fine needle aspiration of pancreatic lesions].

Objective: To investigate the diagnostic value of liquid-based cytology test (LCT) in pancreatic lesions sampled by ultrasound-guided fine needle aspiration (EUS-FNA).

Methods: A retrospective analysis of 556 cases of LCT smears sampled by EUS-FNA of pancreatic lesions was performed, and 164 cases had histologic diagnosis with subsequent surgical resection or biopsy and immunohistochemistry. The accuracy of the cytologic diagnosis was assessed using the histologic diagnosis as the gold standard. The discrepant cases were reviewed to identify sources of errors.

Results: The satisfactory rate for EUS-FNA was 96.0%(534/556). The sensitivity, specificity, positive predictive value, negative predictive value and diagnostic accuracy were 87.7%(128/146), 13/16, 97.7%(128/131), 41.9%(13/31) and 87.0%(141/162) respectively. The diagnostic accuracy was lower in cystic lesions than that in solid lesions. The LCT sensitivities of adenocarcinoma, lymphoma and neuroendocrine tumors were higher than those of cystic tumors and mesenchymal tumors. False positive diagnosis was mainly due to epithelial abnormalities in inflammatory reaction. False negative diagnosis was mainly due to scanty or lack of tumor cells in the smears, or mild atypia that was insufficient for diagnosis.

Conclusions: EUS-FNA is a valuable tool for the diagnosis of pancreatic lesions. Standardized terminology and nomenclature are helpful to improve the diagnostic accuracy.