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).