Evaluation of Innovative Skin-Marking Technique Performed Before Thyroid Ultrasound-Guided Fine-Needle Aspiration Biopsies

Abstract

To introduce an innovative skin-marking technique performed before ultrasound-guided fine-needle aspiration biopsy (US-FNAB) of the thyroid. We studied 248 patients with thyroid nodules, who were classified on the basis of physical examination into two groups-those with palpable nodules (N = 127) and those with nonpalpable or difficult-to-palpate nodules (N = 121). Each group was further subdivided according to the size of the thyroid nodule (< or = 15 mm versus >15 mm). Before US-FNAB, we performed the skin-marking technique with the aid of a catheter, a permanent marker, and ultrasound guidance. An established point for needle entry was indicated on the skin. The chi-square test was used to compare results between the groups of patients. The proportions of adequate and insufficient biopsy material in the overall group of patients were 88.7% and 11.3%, respectively. When the patients were stratified by palpable and nonpalpable thyroid nodules, biopsy specimens were adequate in 89.8% and insufficient in 10.2% of those with palpable nodules, whereas the corresponding proportions for those with nonpalpable nodules were 87.6% and 12.4%, respectively. No statistically significant differences were noted between the two groups. Comparisons between patients with thyroid nodules >15 mm in their largest diameter versus those with nodules < or =15 mm also showed no statistically significant differences in terms of insufficient biopsy material. Our technique creates a marking on the skin that leads directly to the thyroid nodule and facilitates the acquisition of adequate cytologic material. This is particularly relevant when small transducers are not available or when the physician needs reassurance about the accuracy of the thyroid biopsy site.