EUS FNA Diagnostic Yield of Malignancy in Solid Pancreatic Masses: A Benchmark for Quality Performance Measurement

Introduction: No benchmarking exists to assess EUS/FNA quality performance. Diagnostic yield of EUS/FNA of solid pancreatic masses (SPM) is a potential benchmark because the pre-test probability that a SPM is malignant is high (80–90%) and the EUS/FNA sensitivity for diagnosing malignancy is good (80–90%).

Purpose: To determine the cytologic diagnostic rate of malignancy in EUS/FNA of SPM, and to determine if variability among centers and endoscopists exists.

Methods: Multi-center, retrospective study involving 21 EUS sites. Centers were asked to provide the cytology report for all EUS/FNA of solid, non-cystic, ≥10mm short axis diameter pancreatic masses aspirated during a 1-year period.

Results: 1075 patients underwent EUS/FNA in 21 centers (81% academic) involving 41 endoscopists. The median number of SPM EUS/FNA performed during the year per center was 46 (range 4–177), and per endoscopist was 19 (range 1–97). The mean mass dimensions were 32mm x 27mm. The mean number of passes was 3.5. The overall diagnostic rate of malignancy was 71% (95% CI, 0.69, 0.74), with 5% suspicious for malignancy, 6% atypical cells, and 18% negative for malignancy. The median diagnostic rate per center was 78% (range 39%-93%; 1^st quartile 61%), and per endoscopist was 75% (range 0%-100%; 1^st quartile 52%) Multivariate analysis revealed the variables associated with positive malignant diagnostic yield were older age, female gender, body/tail location, greater short axis diameter, and fewer # passes.

Conclusions: 1) EUS/FNA cytology was diagnostic of malignancy in 71% of solid pancreatic masses biopsied. 2) There was large variation in diagnostic yield among EUS centers and endoscopists. 3) Endoscopists with a final cytologic diagnosis rate of malignancy for EUS/FNA of solid masses which is less than 52% are in the lowest quartile, and should evaluate reasons for their low yield.