Nodular Lesions and Thyroid Cancer in Graves’ Disease
Thyroid nodules in patients with Graves' disease (GD) are common and much controversy surrounds the incidence of coexistent thyroid cancer. In order to more accurately estimate this frequency we studied retrospectively 103 patients operated for GD in the University Clinic St Luc in Brussels, Belgium between 1990 and 2000. The patients were classified as Group I – with a solitary palpable nodule (n = 5; 4,9%); Group II – with multiple palpable nodules (n = 13; 12,6%); Group III -with a large diffuse goiter without clinical evidence of thyroid nodules (n = 85). Group III was subdivised in: Group Illa – with nodule(s) evidenced by imaging techniques – radionuclide imaging and/or ultrasonography (n = 18; 17,5%) and Group lllb – with diffuse goiter (n = 67; 65%).
Our study shows that 35% (36/103) of a cohort of 103 subjects with GD had thyroid nodules. Eight patients (8/103 – 7,8%) had differentiated papillary cancer, all but one tumour were microcarcinomas. Malignancies were significantly more frequent when nodules were found on clinical examination (p = 0,03). We also observed more thyroid cancers in the total group of patients with nodules than in those with non-nodular diffuse goiter (p = 0,02).
Our results suggest that thyroid nodules are frequent in GD and that differentiated cancers have high prevalence in GD patients with nodular lesions. Although in most cases there is no aggressive histological pattern, caution is needed in the follow-up.
Keywords: Graves' disease, thyroid cancer, nodule.