Comparison of Diagnostic Yield and Efficacy of Pancreatic Fine Needle Aspiration and Core Needle Biopsy Processing Techniques

Summary: Introduction: Endoscopic ultrasound-guided (EUS) fine-needle aspiration (FNA) and/or core-needle biopsy (CNB) are performed for sampling and pre-operative evaluation of pancreatic lesions, with EUS-CNB a more recent and evolving technique. Studies have compared the procedural efficacy and diagnostic yield of both. In this study, we compared metrics between patients with FNAs and CNBs processed together in the cytology department and evaluated by cytopathologists (study group), with patients that had FNAs and CNBs processed separately and diagnosed by cytopathologists and surgical pathologists independently (control groups). Materials and Methods: This was a retrospective study in a tertiary health center. The study group (group I) consisted of cases (n=20) from 07/2023-03/2024. The control group consisted of 40 cases from 2018-2021. ROSE was performed for all procedures. Clinical, radiological, and pathological parameters were recorded. Diagnostic yield for the study and control groups was calculated by dividing cases with definite diagnoses by the total number of cases. Results: Diagnostic yield was 90% (18/20) in the study group, 50% (10/20) in the FNA control (group II), 30% (6/20) in CNB control (group III) (table 1, figure 1). The mean number of passes was 3.45 for group I and 2.85 for control group overall. Specimen adequacy for ancillary testing including molecular work-up was 55%, 20% and 16% for groups I-III, respectively. Obscuring artefacts were comparable for the study and control groups (table 2, figure 2). Conclusions: In our study, processing FNAs and CNBs of pancreatic lesions together in the cytology department greatly improved diagnostic yield and specimen adequacy for ancillary testing when compared with specimens processed separately. This allowed comprehensive analysis with real time evaluation of cytological and histological features. This differed from previous literature which found all three groups comparable. Institutional quality management projects may be needed to find the optimal procedural protocol for evaluating pancreatic lesions.