Thyroid Nodules with 2 Prior Inadequate Fine-Needle Aspiration Results: Effect of Increasing the Diameter of the Needle

Objective: The major limitation of ultrasound-guided fine-needle aspiration biopsy (US-FNAB) procedures of thyroid nodules are the cytologically nondiagnostic results. The role of increasing the diameter of the needle in the third FNAB (FNAB#3) due to inadequate cytology has as yet not been investigated. The aim of the present study was to evaluate whether increasing the needle diameter could improve the cytologic sampling of thyroid nodules following 2 previous nondiagnostic US-FNAB results.Methods: Between July 2012 and December 2012, 140 consecutive patients with 2 prior nondiagnostic US-FNAB results were enrolled in this prospective investigation. Group 22G consisted of 70 patients (78.5% women; mean age, 52 years) having nodules examined with a 22-gauge (G) needle. Group 27G consisted of 70 patients (75.7% women; mean age, 53 years) having nodules examined with a 27-G needle.Results: The rate of nondiagnostic FNAB results was 42.8% (30 of 70) in group 22G and 64.3% (45 of 70) in group 27G, which was a significant difference (P = .011). The large-bore (22 G) needle was found to be statistically significantly superior compared with the small-bore (27 G) needle in diagnostic ability for predominantly solid (P = .014), irregular (P = .013), and halo-free (P = .021) nodules. The accuracy rate was 64.6 and 38% for large-bore (22 G) and small-bore (27 G) needles, respectively.Conclusion: The results of our study showed that increasing the needle lumen diameter significantly improves diagnostic performance in terms of adequate aspirated material and diagnostic accuracy rate following 2 prior nondiagnostic US-FNABs.Abbreviations: AUS = atypia of undetermined significance FNAB = fine-needle aspiration biopsy G = gauge NPV = negative predictive value PPV = positive predictive value US = ultrasound