Core needle biopsy can minimise the non-diagnostic results and need for diagnostic surgery in patients with calcified thyroid nodules

Purpose

To evaluate the role of core needle biopsy (CNB) for calcified thyroid nodules.

Methods

Between October 2008 and July 2011, 264 patients underwent ultrasound-guided CNB for 272 calcified thyroid nodules at our institution. We retrospectively evaluated the incidence of technical failure, non-diagnostic readings, and the diagnostic performance of CNB, and analysed the relationship between the types of calcification and the CNB results. Finally, the incidence of diagnostic surgery was calculated.

Results

The incidence of technical failure was 1.1 % (3/275) and that of non-diagnostic results was 0.7 % (2/272). The diagnostic accuracy, sensitivity, specificity, positive predictive value, and negative predictive value of CNB were 94.7 %, 89.5 %, 100 %, 100 %, and 90.2 %, respectively. There were no significant differences according to the calcification subtype for either the non-diagnostic results or the incidence of technical failure (P?>?0.99 and P?>?0.99). CNB could prevent diagnostic surgery for 92.9 % (13/14) of the patients who showed more than two non-diagnostic results in previous FNA.

Conclusions

CNB can minimise the non-diagnostic results as well as diagnostic surgery in patients with calcified thyroid nodules. Therefore, CNB may be used as a first-line diagnostic tool for calcified thyroid nodules rather than FNA.

Key points

? CNB results show the low incidence of technical failure (1.1 %, 3/275). ? CNB results show the low non-diagnostic rate (0.7 %, 2/272). ? There were no significant differences according to the calcification subtype. ? CNB can prevent unnecessary diagnostic surgery in 92.9 % (13/14).