A prospective, single-blind, randomized, controlled trial of EUS-guided FNA with and without a stylet.

Background Most endosonographers use an EUS needle with an internal stylet during EUS-guided FNA (EUS-FNA). Reinserting the stylet into the needle after every pass is tedious and time-consuming, and there are no data to suggest that it improves the quality of the cytology specimen. Objective To compare the samples obtained by EUS-FNA with and without a stylet for (1) the degree of cellularity, adequacy, contamination, and amount of blood and (2) the diagnostic yield of malignancy. Design Prospective,single-blind, randomized, controlled trial. Setting Two tertiary care referral centers. Patients Patients referred for EUS-FNA of solid lesions. Intervention Patients underwent EUS-FNA of the solid lesions, and 2 passes each were made with a stylet and without a stylet in the needle. The order of the passes was randomized, and the cytopathologists reviewing the slides were blinded to the stylet status of passes. Main Outcome Measurements Degree of cellularity, adequacy, contamination, amount of blood, and the diagnostic yield of malignancy in the specimens. Results A total of 101 patients with 118 lesions were included in final analysis; 236 FNA passes were made, each with and without a stylet. No significant differences were seen in the cellularity ( P = .98), adequacy of the specimen ( P = .26), contamination ( P = .92), or significant amount of blood ( P = .61) between specimens obtained with and without a stylet. The diagnostic yield of malignancy was 55 of 236 specimens (23%) in the with-stylet group compared with 66 of 236 specimens (28%) in the without-stylet group ( P = .29). Limitations Endosonographers were not blinded to the stylet status of the passes. Conclusions Using a stylet during EUS-FNA does not confer any significant advantage with regard to the quality of the specimen obtained or the diagnostic yield of malignancy. (Clinical trial registration number: NCT 01213290).