Accuracy and other quality indicators of solid pancreatic mass endoscopic ultrasound-guided fine needle aspiration and biopsy in two academic endoscopy centers

Abstract

Background and aims : Endoscopic ultrasound fine-needleaspiration/biopsy (EUS-FNA/FNB) is highly accurate, but dis-crepancies between cytological and surgical diagnoses are stillobserved. We aimed to determine its accuracy and monitor qualityindicators in our facilities. Patients and methods : We performed a retrospective review ofall cases of pancreatic solid lesions evaluated by EUS-FNA/FNB,between July 2015 and June 2018, in two centers. Cytologicaland surgical findings were categorized into five groups: benign,malignant, suspect of malignancy, undetermined and insufficientfor diagnosis. Final diagnosis was based on surgical diagnosis and,in patients who did not undergo surgery, on clinical outcome after6 months follow-up. Results : Altogether, 142 patients were included. FNA was thepreferred tissue acquisition method (88%), with a predilection forthe FNA 22G needle (57%). Cytology was insufficient for diagnosisin 2 cases, therefore a full diagnostic sample was available in 98.6%of the patients (>90%, ESGE target). Fifty-five (38.7%) patientsunderwent surgery. In term of cancer diagnosis, comparison withfinal surgical pathology (n=55) revealed 89% true positives, 5.5%true negatives, 3.6% false positives and 1.8% false negatives. Whencombining surgical diagnosis and clinical outcomes together, EUS-guided sampling sensitivity was 97.4% (92.5-99.5), specificity was92.3% (74.9-99.1), positive predictive value was 98.2% (93.6-99.5),negative predictive value was 88.9% (72.3-96.1) and accuracy was96.4% (91.9-98.8). Post-procedural acute pancreatitis was reportedin 2 patients (1.4%). Conclusions : These results reveal a performance for diagnostictissue sampling well above the ESGE proposed target standard.Also, the uncommon high specificity illustrates the determiningrole of the pathologist’s final interpretation and diagnosis.