Contribution of scintigraphy and ultrasonography to the prediction of malignancy in thyroid nodules with indeterminate cytology Contribuição da cintilografia e ultrassonografia para a predição de malignidade em nódulos tireoidianos com citologia indeterminada

Objective: To evaluate the contribution of 131I scintigraphy and ultrasonography to the prediction of malignancy in thyroid nodules with indeterminate cytology in euthyroid patients. Subjects and methods: The sample consisted of 102 patients with thyroid nodules, submitted to FNAC and presenting an indeterminate cytological diagnosis (follicular neoplasm). Results: Malignancy was observed in 19/25 (76%) nodules with suspicious ultrasonographic characteristics versus 5/77 (6.5%) without suspicious findings. When 131I scintigraphy showed a cold or hot nodule, the chance of malignancy was 38.5% and 2.5%, respectively. This exam was inconclusive in 10% of the patients. Conclusions: Surgery is indicated when a thyroid nodule with indeterminate cytology exhibits suspicious ultrasonographic characteristics. Otherwise, 131I scintigraphy can exclude thyroidectomy when reveals uptake in the nodule, which is observed in half the cases. Arq Bras Endocrinol Metab. 2010;54(1):56-9