Endocrine Abstracts

Introduction: Graves’ disease (GD) is a common autoimmune thyroid disease. The association between GD and thyroid carcinoma (TC) remains controversial. We describe two patients presenting this association.

Case report: Case 1 a 46 years old woman with clinical history of type 2 diabetes, she was diagnosed with Graves’ disease and multiple nodules were found in her enlarged thyroid gland by ultrasonography. The patient underwent total thyroidectomy after the achievement of euthyroïdism by medical treatment. Histopathological study demonstrated a papillary thyroid carcinoma without capsular invasion. Case 2 a 36 years old woman, with no known past medical history, the diagnosis of GD was based on the findings of biological hyperthyroidism, thyroid gland enlargement and the presence of TSH receptor antibodies. Total thyroidectomy was performed for methimazole-induced agranulocytosis. Histopathological study demonstrated an 8 mm follicular thyroid carcinoma with massive vascular invasion.

Discussion: GD is treated with antithyroid drugs, radionuclide therapies, and surgery. The common surgical indications for GD include non-responsiveness to medical or radio-ablative therapies, a large goiter with compressive symptoms, and worsening of ophthalmopathy. Several studies have demonstrated both an increased incidence of follicular thyroid cancer in surgical treated Graves’ disease patients, with rates varying from as low as 1% to as high as 9% of cases. The mechanisms responsible for the increased thyroid cancer incidence in patients with GD remains to be elucidated. It is thought that thyroid stimulating antibodies may be responsible for this increase. Regarding TC prognosis in GD, it is controversial with some studies showing that GD does not affect TC prognosis and some studies suggesting that GD may be associated with a worse outcome only if cancer is ≥ 1 cm.

Conclusion: In conclusion, a careful evaluation for patients with GD is essential, in order to check the development of possible incidental TC, even if they are nodule free, and total thyroidectomy should be the treatment of choice for Graves’ disease in the presence of nodules.