RESUMO
Objective To evaluate the role of ultrasound for thyroid nodules with atypia of undetermined significance(AUS).Methods From January 2014 to December 2015,83 thyroid nodules with AUS diagnosed by ultrasound-guided fine-needle aspiration biopsy were collected from 1984 subjects. On the basis of ultrasonic features,each thyroid nodule was prospectively classified into one of three categories: low suspicion for malignancy,intermediate suspicion for malignancy,and high suspicion for malignancy. Results Among 83 lesions,19 lesions(22.9%) were confirmed malignant,8 lesions (9.6%)were benign,56 lesions (67.5%)had no abnormal changes during clinical follow-up. The nodules were solitary in 36 cases (43.4%)and multiple in 47 cases(56.6%).The maximum diameter was (1.2±0.7)cm. Based on the ultrasonic feature of 19 malignant cases,16 cases (84.2%) were classified as high suspicion for malignancy,2 cases(10.5%) as intermediate suspicion for malignancy,and 1 case(5.3%) for low suspicion for malignancy. Univariate and multivariate analyses revealed that the degree of malignancy of thyroid nodules was significantly associated with ultrasound image classification[OR=9.23(2.96-28.79),P=0.00],but not with age,gender,nodule number,and nodule size (all P>0.05).Conclusion Ultrasound diagnosis by using the present thyroid ultrasound classification system can be helpful for distinguishing malignant and benign AUS thyroid nodules.