Surgeon-performed ultrasound predictors of malignancy in patients with Hürthle cell neoplasms of the thyroid

Abstract

Background: Fine-needle aspiration cannot reliably determine malignancy in patients with Hürthle cell neoplasms (HCNs) of the thyroid. Thyroid nodule size and characteristics determined by surgeon-performed ultrasound (SUS) may be useful for predicting malignancy in HCN preoperatively. This study examined whether tumor size and features by SUS can reliably predict malignancy in patients with HCN.

Materials and methods: We performed a retrospective review of 84 patients with HCN by fine-needle aspiration, who underwent SUS and thyroidectomy from 2002 to 2010. All patients underwent thyroid lobectomy with isthmusectomy unless there was a history of radiation exposure, familial thyroid cancer, obstructive symptoms, bilateral nodules, and/or patient preference, in which case total thyroidectomy was performed. Tumor size and malignant features by SUS were correlated with final histopathology using multivariate regression analysis.

Results: On final histopathology, 29 patients had malignant thyroid nodules and 55 patients had benign ones. There were no statistically significant differences in terms of age, race, ethnicity, or gender between HCN patients who revealed malignant or benign nodules on final pathology. Tumor size ≥ 4 cm measured by SUS did not predict malignancy in HCN. Hypoechogenicity and hyperechogenicity were significantly associated with malignancy, whereas isoechogenicity was predictive of benignity (P = 0.044). No other ultrasonographic features were predictive for thyroid carcinoma by multivariate analysis.

Conclusions: Tumor size and features determined by SUS do not reliably predict malignancy in patients with HCN. Such patients at risk for malignancy should initially undergo thyroid lobectomy for definitive diagnosis.

Keywords: Hürthle cell neoplasm; Malignancy; Nodular characteristics; Surgeon-performed ultrasound; Thyroidectomy; Tumor size.