Objective The frequency of thyroid nodules accompanying Graves’ disease and the risk of thyroid cancer in presence of accompanying nodules are controversial. The aim of this study was to evaluate the frequency of thyroid nodules and the risk of thyroid cancer in patients operated because of graves’ disease. Subjects and methods Five hundred and twenty-six patients in whom thyroidectomy was performed because of Graves’ disease between 2006 and 2013 were evaluated retrospectively. Patients who had received radioactive iodine treatment and external irradiation treatment in the neck region and who had had thyroid surgery previously were not included in the study. Results While accompanying thyroid nodule was present in 177 (33.6%) of 526 Graves’ patients, thyroid nodule was absent in 349 (66.4%) patients. Forty-two (8%) patients had thyroid cancer. The rate of thyroid cancer was 5.4% (n = 19) in the Graves’ patients who had no nodule, whereas it was 13% (n = 23) in the patients who had nodule. The risk of thyroid cancer increased significantly in presence of nodule (p = 0.003). Three patients had recurrence. No patient had distant metastasis. No patient died during the follow-up period. Conclusions Especially Graves’ patients who have been decided to be followed up should be evaluated carefully during the follow-up in terms of thyroid cancer which may accompany. Arq Bras Endocrinol Metab. 2014;58(9):933-8

Purpose: In this study, we aimed to evaluate ABO blood groups and Rh factor in patients with thyroid cancer. Methods: Demographical and clinical features, cytological results, ABO blood groups, and Rh factor status of patients with benign and malignant thyroid disease were evaluated. Histopathological features of thyroid cancer were compared in Rh positive and negative patients, and patients with different ABO blood groups. Results: Histopathological diagnosis was benign in 1,299 (63.5%) and malignant in 744 (36.5%) patients. There was no significant difference between benign and malignant patients in terms of age, sex, thyroid autoantibody positivity, and ABO blood groups (p > .05 for each). A significantly higher rate of patients with malignant disease were Rh positive compared to patients with benign disease (91.8% vs. 88.1%, p = .046). In thyroid cancer patients, extrathyroidal extension and advanced stage (3–4) were observed more frequently in patients with B compared to non-B blood groups (p = .028 and 0.042, respectively). The likelihood of the extrathyroidal extension was 4.272 (95%: 1.816–10.049) times higher in B blood group compared to non-B blood groups in patients with multifocal disease (p < .001). Patients with O blood group had lower rate of capsular invasion than patients with non-O blood groups (p = .018). Conclusion: Patients with B blood group had higher risk of extrathyroidal extension and advanced stage compared to patients with non-B blood group.