Predictors of malignancy in patients with a thyroid nodule that contains Hürthle cells.

Objective: Fine needle aspiration cytology of a thyroid nodule with Hürthle cells can be present in both benign and malignant diseases of the thyroid. The aim of this study was to identify the factors that predict malignancy in patients who underwent thyroidectomy with a preoperative fine needle aspiration cytology that contains a predominance of Hürthle cells.

Study Design: Retrospective data collection.

Setting: Tertiary referral center.

Subjects And Methods: Medical records of 70 consecutive patients were reviewed between March 2005 and August 2010. Predictive factors, as well as age, gender, preoperative serum thyroid-stimulating hormone level, the microscopic findings of fine needle aspiration, ultrasonographic appearance, and size and number of nodules in the pathology report, were correlated with final histopathologic diagnosis of benign or malignant disease.

Results: Patients' final pathology showed that 21 patients (30%) had malignant disease, of whom 15 patients (71.4%) had papillary carcinoma and 6 patients (28.6%) had Hürthle cell carcinoma. Forty-nine (70%) patients had benign disease (hyperplastic/adenomatoid nodule in 24 patients, Hashimoto thyroiditis in 18 patients, Hürthle cell adenoma in 5 patients, and follicular adenoma in 2 patients). The rate of malignancy was higher in male patients (42.9% vs 28.6%), with nodules measuring ≥2 cm (36.7% vs 25.0%), the presence of a solitary nodule (34.3% vs 27.7%), and the presence of metaplasia in fine needle aspiration (36.4% vs 27.1%), although none was found to be significant (P > .05).

Conclusion: Thyroid nodules that are reported in cytology as Hürthle cell lesions require surgery to differentiate benign from malignant disease.