Effect of histological examination on the diagnosis of pancreatic mass using endoscopic ultrasound fine-needle aspiration

Abstract

Background. Endoscopic ultrasound fine-needle aspiration (EUS-FNA) is a well-established method for the diagnosis of solid pancreatic lesions. However, the diagnostic yield of EUS-FNA for pancreatic lesions varies at around 70–90%. Samples from EUS-FNA consist of cells and tissues that can be analyzed separately, and the results can be combined for a final diagnosis. Objectives. To investigate the effect of cytological and histological analysis of EUS-FNA samples on the final diagnosis, and identify factors that may affect the accuracy of the cytological, histological, and overall analysis. Materials and methods. A single-center prospective observational study was conducted at a tertiary university hospital from July 2018 to June 2019. Patients who underwent EUS-FNA for pancreatic solid lesions with a 22-gauge EUS-FNA needle were included in our study. Liquid-based cytological analysis of the specimen and histological analysis of the whitish core were performed, and factors that affected the diagnostic accuracy of each analysis were evaluated. Results. In 63 EUS-FNA samples, the overall diagnostic accuracy was 87.3%, which was significantly higher than the cytological accuracy of 73.8% (p = 0.031) and the histological accuracy of 69.8% (p = 0.001). Factors that affected the results differed in each group: 1) cytological analysis: size, location, and approach method; 2) histological analysis: specimen weight; and 3) overall analysis: size, location, and approach method. Conclusions. Histologic evaluation of core material obtained from EUS-FNA improved diagnostic accuracy, and factors that affected each result were analyzed. Further studies with prospective randomized trials are recommended to support our data.