Endocrine Abstracts

JOINT1824

Introduction: Although the most common cases of hyperthyroidism are due to Graves’ disease, it is a rare circumstance when this condition occurs in patients with personal history of thyroid lobectomy. This is a case report of newly developed Graves’ disease in a female patient with concomitant urinary system disorder, three years after partial thyroidectomy.

Case presentation: We present the case of a 57 years-old female with previous history of left hemithyroidectomy for large follicular thyroid adenoma, 3 years before. Thyroid function had been normal before surgery, with negative TPO antibodies and normal ultrasonographic appearance of the right thyroid lobe. Postoperatively, she received low dose of levothyroxine replacement therapy until her current presentation in our service. Her medical history included anterior pelvic exenteration for infiltrative carcinoma of the urinary bladder in 2019, postoperative radiotherapy and surgery for left aortic arterio-ureteral fistula, resulting in left nephrostomy, right ureterostomy and chronic kidney disease. Currently, she addresses to the endocrinology department complaining of weight loss, spontaneous retrobulbar pain, diplopia and hyperlacrimation. Thyroid function tests show TSH supression and increased FT4 (x 1.1 above ULN). Six weeks after discontinuation of levothyroxine therapy, thyroid function remains unchanged, TPO antibodies are slightly elevated (25 U/ml) and anti-TSH receptor antibodies present high levels (8.7 U/l- 5 times ULN). Ultrasonography revealed enlarged right thyroid lobe, with heterogeneous echotexture and hypervascularisation on color Doppler exam. Detailed ophtalmological evaluation is yet to be completed. Initiation of methimazole therapy is recommended and regular endocrine evaluation will be performed.

Conclusion: The physiopathological mechanism involved in the occurence of Graves’ disease following hemithyroidectomy is still unclear. It may imply an overactive immune response, genetic factors or an environmental component. So far there are no predictive factors associated with development of this condition that are worth taken into account preoperatively. No cases showing association between bladder neoplasm and thyroid autoimmune disease or thyroid adenoma have been reported in the literature so far.