Ultrasound predictors of malignancy in indeterminate thyroid nodules.

ABSTRACT

BACKGROUND: Asymptomatic thyroid nodules are an increasingly common clinical problem. Lesions greater than a centimetre require cytological assessment. Indeterminate lesions often need surgical excision to establish a definitive diagnosis and plan further management. If a definitive diagnosis could be accurately predicted pre-operatively, the most appropriate surgical procedure could be performed at the initial operation. AIM: The aim of this study was to identify whether specific thyroid ultrasound features could predict malignancy in indeterminate thyroid nodules. METHODS: A retrospective review of all patients undergoing surgery for an indeterminate thyroid lesion between 2006 and 2012 was performed. Demographic features, surgical intervention and final histological findings were determined. Pre-operative ultrasound findings and final histology were correlated and the ultrasonic markers predictive of malignancy were determined. RESULTS: A total of 40 patients were identified as having undergone surgical intervention for indeterminate thyroid nodules. The majority of patients were diagnosed with a follicular adenoma (n = 22; 55 %). Papillary thyroid carcinoma was identified in three patients (7.5 %) and follicular carcinoma in a further 3 (7.5 %). Ultrasound features associated with malignancy included poorly defined nodule borders and increased vascularity. The presence of malignancy was not related to nodule size, echogenicity or the presence of calcifications. CONCLUSIONS: The majority of indeterminate thyroid lesions are benign on final histological assessment. High nodule vascularity associated with ill-defined borders is associated with malignancy. Further research is warranted to identify predictors of malignancy in indeterminate nodules in order to avoid unnecessary or repeated procedures.