Contribution of scintigraphy and ultrasonography to the prediction of malignancy in thyroid nodules with indeterminate cytology.

Objective: To evaluate the contribution of (131)I 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 (131)I 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, (131)I scintigraphy can exclude thyroidectomy when reveals uptake in the nodule, which is observed in half the cases.