J Korean Soc Ultrasound Med.  2012 Mar;31(1):17-21.

Ultrasonography-guided Fine-needle Aspiration for Solid Thyroid Nodules Less than 5 mm in the Largest Diameter: Comparison in Diagnostic Adequacy and Accuracy According to Nodule Size

• Lee JH
• Kim DW
• Baek SH

Abstract

PURPOSE
This study assessed the adequacy and accuracy of ultrasonography (US)-guided fine-needle aspiration (US-FNA) of solid thyroid nodules, less than 5 mm in maximum diameter.
MATERIALS AND METHODS
From January to December 2009, US-FNA was performed for small solid thyroid nodules in 201 patients. Each thyroid nodule was classified into group A and B according to the largest diameter (1 mm < or = group A < 3 mm and 3 mm < or = group B < 5 mm). The adequacy and accuracy of US-FNA in two groups were compared using the histopathological results as a reference standard.
RESULTS
Of the 227 thyroid nodules in 201 patients, the inadequacy of US-FNA in group A and B was 24.3% (18/74) and 13.1% (20/153), respectively, showing a statistically significant difference between the two groups (p = 0.0333, chi-square test). Eighty nodules were removed surgically in 72 patients, from which papillary thyroid carcinoma (n = 52), follicular thyroid carcinoma (n = 1), nodular hyperplasia (n = 26), and pseudonodule related to thyroiditis (n = 1) were confirmed. Based on the histopathological results of the 80 surgical nodules, the sensitivity, specificity, positive predictive value, negative predictive value and accuracy of US-FNA in group A and B were 55.0% and 79.4%, 81.8% and 100%, 84.6% and 100%, 50% and 68.2%, and 64.5% and 85.7%, respectively.
CONCLUSION
The adequacy and accuracy of US-FNA for solid thyroid nodules, > or = 3 mm in the largest diameter, were higher than those of US-FNA for very small nodules, < 3 mm in the largest diameter.

Keyword

Thyroid; Thyroid nodule; Biopsy, Fine-needle; Ultrasonography; Malignancy

MeSH Terms

Adenocarcinoma, Follicular
Biopsy, Fine-Needle
Carcinoma
Humans
Hyperplasia
Sensitivity and Specificity
Thyroid Gland
Thyroid Neoplasms
Thyroid Nodule
Thyroiditis
Carcinoma
Thyroid Neoplasms