A novel diagnostic classification for EUS-FNA/B pathological diagnosis

Abstract

Pancreatic pathology traditionally involves postoperative pathological diagnosis and comparison with imaging. Preoperative diagnosis has partly relied on pancreatic cytology. However, its clinical contribution has been limited due to issues, such as sample quality and volume. However, the advent of endoscopic ultrasound-guided fine-needle aspiration/biopsy (EUS-FNA/B) has significantly changed pancreatic pathology. Particularly, the ability to perform pathological diagnosis before treatment has become crucial in the pancreatic tumor domain, in which many tumors are unresectable, providing important diagnostic evidence. Recently, the efforts of gastroenterologists have stabilized sample quality and volume, contributing significantly to improvements in pathological diagnostic performance. Conversely, the sample volume obtained by EUS-FNA/B remains relatively small compared to obtained in the case of other diseases, and issues such as interfacility variability, still remain to be addressed. Therefore, to stabilize and improve diagnostic accuracy, we reported on the classification of pathological diagnoses of pancreatic solid tumors to improve the pathological diagnosis of pancreatic ductal adenocarcinoma. It demonstrated that clarifying the characteristic features and delegating the consensus on "suspicious for malignancy" to each facility resulted in improved inter-pathologist diagnostic agreement. This study provides an overview of the diagnostic classification and useful information for daily clinical practice.