Diagnostic yield of malignancy during EUS-guided FNA of solid lesions with and without a stylet

Abstract

Background Use of a stylet during EUS-guided FNA (EUS-FNA) is believed to improve the quality and diagnostic yield of specimens.

Objective To compare samples obtained by EUS-FNA with (S+) and without (S−) a stylet for diagnostic yield of malignancy and cytological characteristics.

Design Randomized, controlled trial.

Setting Tertiary referral center.

Patients Consecutive patients referred for EUS-FNA of solid lesions.

Intervention EUS-FNA; the number of passes was determined by lesion site (6 pancreas/others and 4 lymph nodes).

Main Outcome Measurements Diagnostic yield of malignancy and degree of cellularity, specimen adequacy, contamination, and amount of blood.

Results One hundred patients were prospectively enrolled in this randomized, controlled trial and the sites of EUS-FNA were the pancreas, 58; lymph node, 25; and other, 17. The overall diagnosis was malignancy in 56, benign in 30, suspicious/atypical in 7, and inadequate specimen in 7 lesions. There were 550 passes made (275 with a stylet and 275 without a stylet). Interim analysis demonstrated no difference in the diagnostic yield of malignancy (94 passes with a stylet [34.2%] vs 110 without a stylet [40%], P = .2) and in the proportion of inadequate specimens (57 with a stylet [20.7%] vs 64 without a stylet [23.3%], P = .2). There was no difference with regard to cellularity (P = .83), contamination (P = .31), number of cells (P = .25), and amount of blood (P = .6). Similar results were noted in a subgroup analysis based on lesion site. Applying the rules of futility, the study was terminated.

Limitations Subjectivity in cytopathologists' assessment, endosonographer not blinded.

Conclusions There was no difference in the diagnostic yield of malignancy or proportion of inadequate specimens between passes with and without a stylet. These results suggest that the use of a stylet does not confer any advantage during EUS-FNA. (Clinical trial registration number: NCT01316614.)