The risk factors for malignancy in surgically treated patients for Graves' disease, toxic multinodular goiter, and toxic adenoma

Abstract
Background The impact of age, gender, and coexisting cold nodules on the frequency of thyroid carcinoma in hyperthyroid patients in an endemic iodine-deficient region was investigated. Methods The medical records of 817 patients who underwent operations for Graves' disease (GD) (n= 342), toxic multinodular goiter (TMG) (n = 299), and toxic adenoma (TA) (n = 176) between January 1988 and April 2006 were reviewed. Results Cold nodules were found in 293 (36%) of the patients, and 524 (64%) patients had no cold nodules. The incidence of thyroid carcinoma was 6.5% (53/817).The frequency of carcinoma was 3.8% in GD, 6.4% in TMG, and 12% in TA. The frequency of carcinoma in older patients (≥50 years) was significantly higher than in younger patients (10.2% vs 4.3%, P = .001). The presence of cold nodules significantly increased the frequency of carcinoma (13% vs 2.9%, P = .001). A tumor was discovered within a cold nodule in 45% of the patients with thyroid carcinoma. Conclusion Cold nodules are frequent in hyperthyroid patients in endemic iodine-deficient regions. Older patients (≥50 years) and cold nodules are significant risk factors for malignancy in patients with hyperthyroidism. Surgical treatment may be suitable for those particular patients if malignancy can not be excluded.