Endocrine Abstracts

JOINT2281

Background: Graves disease is one of the most common thyroid pathologies with multiple risk factors that may present with various clinical manifestations. Because of the small number of cases, there is ongoing debate whether postoperative GD can be associated with previous autoimmunity exacerbated by exogenous stress or new onset improper response of the immune system after partial thyroidectomy. Theory suggests that during surgery, injured thyroid follicular cells release THS-R which are picked up by APC that induces Th2 humoral response. Risk factor of this phenomenon might be genetic predisposition to autoimmunity.

Case Presentation: A 23 years old Caucasian female admitted to the hospital with the complaints of general weakness, palpitation, sleep disturbances, hand tremor, headache, irregular menstrual cycle, increased appetite and sweating. 3 years ago, a patient was diagnosed with a dynamically growing nodule measuring 38 mm with euthyroid state confirmed by laboratory tests. Fine-needle aspiration excluded malignancy. The patient underwent hemithyroidectomy (histomorphology confirmed a nodular goiter). Postoperatively, subclinical hypothyroidism was identified, and levothyroxine therapy was initiated, however, the patient stopped taking medication. In family history, mother has hypothyroidism and Sjogren’s disease. On physical examination, there was a tremor of the outstretched hands, moist and warm skin, slight exophthalmos, and a positive Graphe’s sign. Initial lab tests revealed thyrotoxicosis: TSH – 0.09 MKU/ml, FT4 – 24.28 pmol/l; FT3 – 7.61 pmol/l, Thyreoglobulin – 26.910 ng/ml (3.5-7.7) anti-TSH-R – 6.5 IU/l(normal range < 1.0). Moreover, an ultrasound revealed a coarse-grained left thyroid lobe in the size of 4.7cc with irregular echogenicity. Color Doppler imaging demonstrated enhanced blood flow in the parenchyma. Scintigraphy revealed increased uptake of Tc-99m in the remnant left lobe of the thyroid gland. Based on these findings, a diagnosis of Grave’s disease was made. The patient was started on methimazole and Beta-blocker with symptomatic and laboratory improvement.

Conclusion: This is a rare case of new onset Graves disease after partial thyroidectomy. Case highlights importance of post-surgical follow-up and screening including TFTs. In the presence of Hyperthyroidism after lobectomy, Grave’s disease should be considered in broad differential diagnosis. Even though it indicates possible improper immune response to released TSH-R during the surgery, further research is needed to understand pathophysiology of association between GD and thyroid surgery.