Endocrine Abstracts

Introduction: Goiter means that the thyroid gland is larger than the normal size for the patient’s age and gender. Some of the causes of goiter are iodine deficiency, thyroid nodules, Graves’ disease(GD). Goiter, hyperthyroidism, ophthalmopathy and dermopathy can be seen in GD. Compression symptoms due to goiter (dyspnea, dysphagia, superior vena cava syndrome) are also seen. Here, we will present a case of GD with superior vena cava syndrome.

Case: A 50-year-old male patient, who had been using methimazole for 6 years due to hyperthyroidism, applied to our outpatient clinic with swelling in the neck. The patient was taking methimazole 10 mg/day. On physical examination, he had goiter, bilateral venous collaterals in the neck, and inactive Graves’ ophthalmopathy. Pemberton’s sign was positive. In laboratory tests, TSH, fT4, fT3, antiTPO, antiTG, TSH receptor antibody were: <0.008 mU/l, 1.01 ng/dl, 10.6 ng/l, >13000 U/l(<60 negative), 724 IU/ml (<1.3 negative), 34.3 U/l (≤1 negative), respectively. In the thyroid ultrasound, the dimensions of the right lobe were 33.9x33.4x73.4 mm, the dimensions of the left lobe were 35.3x50x78.5 mm, the dimension of the isthmus was 20 mm, no thyroid nodule was observed. The thyroid gland showed retrosternal extension. Thyroid scintigraphy was consistent with GD. Computed tomography of the neck and thorax was performed to evaluate the differential diagnosis and cervical region: The dimensions of both thyroid lobes have increased considerably, extending to the paraesophageal, paratracheal, and intrathoracic retrosternal areas, and significant extrinsic compression of the larynx and esophagus was observed. In addition, bilateral subclavian veins were pressed by the thyroid gland, and diffuse dilated venous structures were observed in the skin-subcutaneous part of the anterior of the thyroid. Varicose dilated veins were observed in the anterior mediastinum. (Secondary to subclavian vein compression?). No pathological finding was detected in the lung parenchyma. Bilateral total thyroidectomy was performed. Its pathology was reported as diffuse toxic hyperplasic thyroid gland. Venous collaterals in the neck of the patient disappeared in the postoperative period. Clinical improvement was observed.

Conclusion: The most common cause of hyperthyroidism is GD. Compression symptoms due to diffuse hyperplasia of the thyroid gland may be seen. In particular, the retrosternal extending goiter may cause superior vena cava syndrome by compressing the vascular structures. The most common cause of superior vena cava syndrome is malignancy. GD should also be considered in the differential diagnosis of superior vena cava syndrome. Improvement in this situation is expected with thyroidectomy.