Core needle biopsy of thyroid nodules - evaluation of diagnostic utility and pain experience

A crucial problem in the non-operative diagnosis of thyroid nodules is the significant amount of non-diagnostic biopsies. This is a challenge for practicing endocrinologists especially when the results of the repeated biopsies remain non-diagnostic. The lack of a concrete preoperative diagnosis may result in unnecessary thyroidectomies in patients. Alternatively, it may also lead to the delayed diagnosis of cancer. One method of biopsy specimen acquisition that could potentially increase the diagnostic accuracy of thyroid biopsies is the application of core-needles. The aim of the study was to compare the diagnostic value and patient tolerability of core-needle aspiration biopsies (CNAB) with fine-needle aspiration biopsies (FNAB).

The study included patients with thyroid nodular goiter in whom previous conventional FNAB yielded non-diagnostic results. CNABs were performed using 22G core-needles. The control group consisted of patients undergoing conventional FNAB with 25G fine-needles. Pain during core-needle biopsies of thyroid nodules was assessed using the 10-point visual analog scale.

There were a total of 30 lesions in 26 patients undergoing CNAB (22 women, 4 men, mean age 48.3) and a total of 59 lesions in 40 patients undergoing FNAB (34 women, 6 men, mean age 57.3). 56.6% of CNABs and 50.8% of FNABs were diagnostic (p=0.60). When assessing pain via the visual analog scale, the median score for biopsies performed with core-needles was four. 60.0% of patients considered the pain of core-needle aspiration biopsies to be similar to the pain experienced during the previous conventional fine-needle aspiration biopsies, while 40% of patients claimed that the pain was more intense.

CNAB did not prove to be superior to FNAB. Despite the larger needle gauge used during core-needle biopsies, the patients' tolerability was comparable to conventional fine-needle biopsies.