Endocrine Abstracts

Introduction: Papillary thyroid carcinomas (PTC) represent up to 87% of all thyroid cancers with an incidence that has doubled over the past 30 years. Hashimoto’s thyroiditis (HT) and Graves’ disease are two autoimmune thyroid diseases representing the most common causes of hypothyroidism and hyperthyroidism, respectively. Although PTC with coexisting HT has been reported in literature, its association with GD is not a common condition. Herein, we report three cases of coexisting papillary thyroid carcinoma and autoimmune thyroid disease: HT in one case and GD in two cases.

Observations: The first case reported a 30-year-old-woman, who has been followed during three years for HT. Her thyroid ultrasound examination revealed a multinodular goiter with a suspicious nodule. Fine needle aspiration cytology showed features of PTC. Total thyroidectomy with lymph node dissection was performed to the patient and postoperative histopathological examination showed the PTC. The second case was a 69-year-old woman who was initially followed for GD with Graves’ophtalmopathy. Her thyroid ultrasound examination showed heterogeneous hypoechoic nodule in the right lobe. After medical preparation, the patient had a total thyroidectomy and the histopathological examination revealed a follicular variant of PTC. The third case reported a 34-year-old man, who presented with symptoms of thyrotoxicosis. On physical examination, he had an asymmetrical goiter with a right nodule measuring 2 cm × 1 cm. Thyroid scintigraphy image was consistent with the diagnosis of GD. Fine needle aspiration biopsy of the right nodule revealed features of PTC. After medical preparation, a total thyroidectomy with lymph node dissection was performed. Histopathological examination confirmed PTC.

Discussion: The pathogenic linkage between autoimmune thyroid diseases and PTC remains unclear. In the case of GD, studies have suggested that thyrotropin receptor antibodies may possibly play a role in the initiation and progression of thyroid cancer. Conversely, many hypotheses have been suggested to explain the relationship between HT and PTC, one of which is the concept of chronic inflammation leading to a neoplastic condition. In patients with autoimmune thyroid disease, thyroid ultrasound should be performed in order to detect suspicious thyroid nodules warranting cytologic analysis.