Role of ultrasound, clinical and scintigraphyc parameters to predict malignancy in thyroid nodule.

Background: This study aimed to evaluate clinical, laboratory, ultrasound (US) and scintigraphyc parameters in thyroid nodule and to develop an auxiliary model for clinical application in the diagnosis of malignancy.

Methods: We assessed 143 patients who were surgically treated at a single center, 65% (93) benign vs. 35% (50) malignant lesions at final histology (1998-2008). The clinical, laboratory, scintigraphyc and US features were compared and a prediction model was designed after the multivariate analysis.

Results: There were no differences in gender, serum TSH and FT4 levels, thyroid auto-antibodies (TAb), thyroid dysfunction and scintigraphyc results (P=0.33) between benign and malignant nodule groups. The sonographic study showed differences when the presence of suspected characteristics was found in the nodules of the malignant lesions group, such as: microcalcifications, central flow, border irregularity and hypoechogenicity. After the multivariate analysis the model obtained showed age (>39 years), border irregularity, microcalcifications and nodule size over 2 cm as predictive factors of malignancy, featuring 81.7% of accuracy.

Conclusions: This study confirmed a significant increase of risk for malignancy in patients of over 39 years and with suspicious features at US.