Ultrasound Score to Select Subcentimeter-sized Thyroid Nodules Requiring Ultrasound-guided Fine Needle Aspiration Biopsy in Eastern China

Abstract

Ultrasound-guided fine needle aspiration biopsy (FNAB) is a costly diagnostic item with a low yield inidentifying the tiny proportion of nodules that actually represent malignant disease. Our aim through this studywas to obtain an ultrasound (US) score for selecting subcentimeter-sized thyroid nodules requiring FNAB ineastern China. Some 248 patients for a total of 270 thyroid nodules less than 1 cm in diameter underwent FNABand subsequent surgery from January 2006 to March 2012 at our hospital. The clinicopathological and US datafrom all the nodules were analyzed retrospectively. An US score was developed on the basis of independentpredictive factors for malignancy. Irregular shape, hypoechogenicity, no well-defined margin, presence ofcalcifications and ratio between antero-posterior and transversal diameters (AP/TR) ≥1 were independentpredictive factors for malignancy on logistic regression analysis. US score were statistically significant, with ≤2favoring benignancy with an 80.3% sensitivity and a 72.7% specificity. US score is useful for differentiatingbetween malignant and benign subcentimeter-sized thyroid nodules. We suggest FNAB for nodules when theUS score is higher than 2.