Fine-needle aspiration cytology of thyroid nodule: does the needle matter?

Ultrasound-guided fine needle aspiration cytology (US-FNAC) represents the most effective test available to distinguish between benign and malignant thyroid nodules. The major limit is the rate of inadequate specimens which generates a much higher cost. The aim of the present study was to evaluate whether the adoption of stylet needles may result in a significant improvement of diagnostic performance in a large, unselected series of nodules.

1468 nodules were submitted to US-FNAC by two different 25-gauge needles: a traditional hollow needle (Ns) or a stylet needle (Ys). Cytological specimens were evaluated in blind conditions by the same cytopathologist.

Ys was associated to a significant reduction of non-diagnostic specimens (2.8% vs 9.1% by Ns, respectively, P < 0.001). Logistic regression analysis taking into account sex, age, needle type, nodule size, multiplicity and structure predictor of successful sampling [odds ratio 3.6 (95.0% CN 2.0-6.4), P < 0.001]. The cost analysis comparing the adoption of the two types of needle evidenced that the cost per adequate specimen was consistently less for Ys than for Ns (euro 78.87 vs euro 90.76).

Our data showed that the adoption of a stylet needle significantly improves diagnostic performance, reducing by about 14% the expenditure per diagnostic procedure. Therefore, we suggest that stylet needles should be widely adopted to perform US-FNAC of thyroid procedures.