DOES ULTRASOUND-GUIDED FINE-NEEDLE ASPIRATION BIOPSY INDICATED FOR SUBCENTIMETER THYROID NODULES? - RETROSPECTIVE EVALUATION OF 6-YEARS SINGLE-CENTER RESULTS

Abstract

Introduction: Fine-needle aspiration biopsy (FNAB) is commonly used for histopathological evaluation of thyroid nodules and frequently for nodules larger than 1 cm. However, the indications of FNAB are also discussed for the subcentimeter nodules, in recent years. The aim of this study is to investigate the necessity of FNAB for subcentimeter nodules.

Materials and methods: The results of 2906 thyroid FNAB evaluated retrospectively which performed between 2012-2017 in Radiology Department of Adana Numune Training and Research Hospital. The nodules greater and smaller than 1 cm in size were compared. In addition, nodules were classified smaller than 1 cm (5-10 mm), 1-1.5 cm, 1.5-2 cm and greater than 2 cm in size and also according to sonographic echogenicity. Malignancy rates were evaluated in each group. Fisher's exact and Pearson's Chi Square tests were used for statistical analysis and significance was accepted to correspond p <= 0.05.

Results: Malignancy rates with 6.5% in subcentimeter nodules are found to be higher and statistically significant (p=0,022). According to echogenicity, malignancy rate was highest in hypoechoic nodules. The most common malignancy was papillary carcinoma.

Conclusion: Our findings suggest that the FNAB maybe necessary for subcentimeter nodules and we recommend FNAB for subcentimeter nodules especially if sonographic features, which suggest malignancy such as hypoecogenicity, calcification and irregular borders, are seen.