Endocrine Abstracts

Introduction: Elastography is a method of tissue stiffness assessment. It was already demonstrated that thyroid cancers are less elastic than benign lesions. However, little is known about other factors, which might influence the stiffness of thyroid nodules and disrupt the prediction of malignancy using this technique. The aim of this study was to conduct the first systematic assessment of factors potentially affecting elasticity of thyroid lesions.

Methods: 122 patients with thyroid nodules admitted for thyroidectomy underwent preoperative ultrasonography and sonoelastography. The definite diagnosis of thyroid lesions was based on histological examination. First of all, the elasticity of cancers and benign lesions was compared. Secondly, an influence of composition, size, localization, nodularity and selected laboratory parameters on thyroid nodules elasticity was evaluated. Association between above mentioned factors and elasticity was assessed in benign lesions.

Results: There were 22 malignant and 371 benign lesions. There were significant difference in tissue stiffness between benign and malignant nodules (maximal stiffness 55.6 vs 174.2 kPa, P<0.0001). Analysis of benign lesions revealed that presence of some sonographic features is associated with decreased elasticity. Benign nodules with calcifications (P<0.0001) had significantly increased stiffness. Partially cystic nodules were significantly less elastic than solid ones (P=0.03). There was positive correlation between the nodule size and elasticity (P<0.0001). Lesions localized in the isthmus were significantly less elastic than nodules in other localizations (P=0.0001).

Conclusions: We identified several attributes of lesions, including the size and composition that influence the recorded stiffness values of the lesion and need to be considered during interpretation of the results. According to our study, the stiffness values are increased in case of nodules containing calcifications, cystic component, those of size above 20 mm and localized in isthmus.