Endocrine Abstracts

JOINT1674

Introduction: Graves’ disease, the most common cause of hyperthyroidism, is linked to the presence of anti-TSH receptor antibodies. It is an autoimmune pathology, 5 to 10 times more frequent in women than in men, occurring at any age. Clinical symptoms include thyrotoxicosis and the specific signs of the disease (ophthalmopathy and pretibial myxedema). Biologically, a lowered TSHus concentration and elevated T4 and/or T3 confirm the diagnosis. Ultrasound and scintigraphy are sometimes useful in distinguishing Graves’ disease from other causes of hyperthyroidism. When clinical and biological findings are incomplete and/or ultrasound is inconsistent, scintigraphy is of great help. We report on the contribution of scintigraphy to the diagnosis of Graves’ disease with clinical, biological and ultrasound discordance.

Case report: A 54-year-old female patient with breast cancer, operated on 7 years ago and currently undergoing hormone therapy, consulted for thyroiditis discovered incidentally by cervical ultrasound, with a reduced thyroid gland, heterogeneous echostructure with hypoechoic areas, discreetly hypervascularized. Clinically, she showed no signs of dysthyroidism. A laboratory workup revealed subclinical hyperthyroidism with TSHus down to 0.05 μUI/ml (0.25-5), T4L and T3L normal. In the immunological work-up, anti-TPO antibodies were positive at 36 and TRAK was slightly elevated at 2.81 (>2.25). In view of this incomplete clinicobiological context and a discordant ultrasound, a Technicium 99m thyroid scintigraphy was requested as a complement, objectifying diffuse and homogeneous hyperfixation of the radiotracer compatible with Graves’ disease. The patient was put on low-dose synthetic antithyroid drugs. Biological results were favourable (TSH, T4 and T3 normal at 1-month follow-up).

Discussion/Conclusion: The classic diagnosis of Graves’ disease is clinicobiological and secondarily ultrasonographic. However, in the event of discrepancies between the two, and given the operator-dependent nature of ultrasound, scintigraphy can make a considerable contribution.