Endocrine Abstracts

Background: Thyroid AUS/FLUS lesions continue to be a grey area regarding the surgery to be carried out. Our aim was to create a predictive malignancy score to help in surgical decision.

Methods: Retrospective study of 2981 patients and 3557 thyroid Fine-needle aspirations (FNAs) between January 2012 to December 2014. Ultrasound and cytological findings considered suspicious by the ATA guidelines were analyzed. Malignant group was compared with a control group of benign histology using SPSS analysis.

Results: AUS/FLUS rate was 15.9% (564). 180 patients underwent surgery. 54 revealed carcinoma on final histology.

From Q-square test we found: 1) Hypoechoic nodules (HN) and ecographic microcalcifications (MC) are individually associated with malignancy. 2) Taller than wide shape nodules and vascularity findings are significant but not statistic associated. 3) Microfolicular (MF), Hürthle cells (HC) and nuclear changes (NC) are always present in malignant cases but without individual association.

Multivariable analyses showed: 1) presence of 3 cytological findings was associated with higher probability of carcinoma. 2) HN and MC are strongly associated with malignancy.

By logistic regression associating the 5 criteria increased probability of carcinoma. Probabilities were as follows: HN-2.6; MC-18.69; MF-2.48; HC-2.02; NC-1.99. ROC curve was 72.9% above. Sensibility and specificity were 66.2%/72.7% with a cut-off point of 0.50.

Conclusion: A moderate sensibility and a high specificity for malignancy were observed in the association between hypoechoic nodule, ecographic microcalcifications, microfollicular lesions, Hürthle cells and nuclear changes. These criteria can be useful in surgical decision contributing for a possible decrease in the reintervention rate.