Fine needle aspiration of pancreatic cysts: Use of ancillary studies and difficulty in identifying surgical candidates.

Objective: To evaluate ancillary biochemical testing after pancreatic cyst fine needle aspiration (FNA) in the clinical setting.
Study Design: Findings from 110 pancreatic guided FNA were reviewed cysts evaluated by image- and correlated with histology, clinical follow-up and biochemical analysis of cyst fluid and serum. Adequate followup was available for 95.
Results: In terms of identifying cysts requiring surgery, FNA showed 55.3% sensitivity, 95% specificity, 92.9% positive predictive value (PPV) and 64.4% negative predictive value (NPV). FNA showed only nonspecific cyst contents in 51% of cases, but 40% of those patients proved to be surgical candidates at follow-up. Overall, patients with lesions requiring surgery were younger (p = 0.14), more often presented with pain (p = 0.006), had larger cysts (p = 0.05) and less often had a history of chronic pancreatitis (p = 0.12). Among cases in which FNA showed only nonspecific cyst contents, patients with lesions requiring surgery were more often female (p = 0.08), were younger (p = 0.10), had larger cysts (p = 0.06) and had pain at presentation (p = 0.02). Differences in fluid and serum analytes were not statistically significant.
Conclusion: FNA of pancreatic cysts shows high specificity but poor sensitivity, even with cyst fluid and serum biochemical analysis. FNA of cysts requiring surgery often yielded nonspecific cyst cytology and causing a misinterpretation as pseudocysts. Ancillary biochemical analysis of cyst fluid remains problematic in the clinical setting.