How to select nodules for fine-needle aspiration biopsy in multinodular goitre. Role of conventional ultrasonography and shear wave elastography - a preliminary study.

INTRODUCTION: The wide prevalence and relatively low malignancy ratio of thyroid nodular disease (TND) make the selection of suspicious lesions for fine-needle aspiration biopsy (FNAB) a vital problem in endocrinology. Apart from the decision as to whether FNAB is necessary, there is often a second problem - which nodule or nodules to choose in a case of multinodular goitre (MNG), when the number of lesions may be high. The aim of this study was to compare the usefulness of conventional ultrasonography (US) to that of a novel method of tissue stiffness assessment - shear wave elastography (SWE) - in differentiating between malignant and benign nodules and in selecting the most suspicious lesions in MNG.
MATERIAL AND METHODS: Patients with MNG, referred for thyroidectomy irrespectively of indications for surgery, underwent thyroid US and SWE examination before surgery, between August and December 2010. Results of these examinations were correlated with the histopathological outcomes.
RESULTS: 80 patients with 339 thyroid nodules were included. Ten thyroid cancers (TCs) in ten patients were diagnosed in histopathology. All ten cancers were the least elastic lesions in MNG (using quantitative data on maximal tissue stiffness). Four cancers appeared as the biggest lesions in MNG, while one was equally the biggest in a particular goitre (there were other lesions of the same size) taking into account maximal diameter. Three of ten cancers possessed the highest number of suspicious features in MNG, a further four had the highest number equally, with at least one other lesion in the same goitre.
CONCLUSIONS: On the basis of our results, the relatively high stiffness of a lesion compared to other nodules from the same MNG should be considered as a strong argument for choosing that particular one for FNAB.