Diagnostic accuracy of ultrasound and fine‐needle aspiration in the study of thyroid nodule and multinodular goitre

OBJECTIVE: Ultrasonography and cytology obtained by fine‐needle aspiration are part of the basic study of the thyroid nodule. Although they are not diagnostic in every case, they are cost‐effective methods that inform surgical treatment and its extent. The purpose of this study was to evaluate the accuracy of ultrasonography associated with fine‐needle aspiration to predict malignancy in nodular thyroid pathology. DESIGN AND PATIENTS: We collected prospective data from patients undergoing thyroidectomy by single nodule or multinodular goitre between 2006 and 2016. A total of 417 patients were included. Ultrasounds were classified as suspected of malignancy if they had 2 or more of the following characteristics: hypoechogenicity, microcalcifications, intranodular central hypervascularization, irregular margins and poorly defined edges. MEASUREMENTS: Ultrasound and fine‐needle aspiration accuracy. RESULTS: In the postoperative study, 40% presented malignant pathology. 33% of patients with nonsuspicious ultrasound and 73% of those with suspicious ultrasound had malignant disease. Among patients with single nodule and suspicious ultrasound, the malignancy rate reached 80%. As for cytology, 100% of Bethesda VI patients, 88% of V, 63% of IV, 31% of III and 12% of II were found to have carcinoma. The combination of the 2 tests showed a high predictive value, particularly in cases of Bethesda IV cytology. CONCLUSIONS: Thyroid cytology provides high predictive value of the presence of carcinoma. The predictive value of ultrasound is also high, mainly in the study of isolated nodules. The combination of the 2 tests results in increased diagnostic accuracy.