Endocrine Abstracts

Case Report: We reported a case of 54 year old lady who presented with symptomatic hyperthyroidism 11 years after total Thyroidectomy. She remained well controlled on average 100 mg of Levothyroxine until presented with persistently supressed TSH despite weaning off and later withdrawal of levothyroxine (T4 16 pmol/land TSH <0.03 pmol/l) and elevated Thyroid Stimulating Antibodies (TSI) (>40 iu/l). Her Thyroid ultrasonography showed remnants of thyroid tissue in the thyroid surgical bed. Pertechnetate scintigraphy showed multiple foci of active thyroid tissue; 13 mm nodule anterior to thyroid cartilage, 5 mm right paratracheal nodule and 2 small left thyroid nodules. Her Fine needle aspiration confirmed benign thyroid Tissue (Thy2). She also developed mild Thyroid eye Disease managed with eye drops and selenium 200 mg. She was commenced on carbimazole 10 mg once a day. Although surgery will be challenging, she has been referred to surgeons for consideration of removal of remnant thyroid tissues. Radioactive Iodine Treatment is best definitive treatment option as MRI Orbit did not show any active thyroid eye disease but she will likely need steroid cover to prevent progression of Thyroid eye symptoms.

Discussion: Graves’ Disease is an autoimmune condition characterize by production of auto antibodies against thyroid-stimulating hormone receptor (TRAb). Total Thyroidectomy removes target tissue for TRAB and controls hyperthyroidism. Surgical Thyroid resection reduces TRAb levels in variable degrees. The median half-life of TRAb has been estimated 93.5 days after total thyroidectomy in patients without Graves Ophthalmopathy(GO)or smoking and 357.4 days in patients with GO and smoking .

Conclusion: This case therefore demonstrates recurrence of thyrotoxicosis in remnant thyroid tissue stimulated by TRAb presenting years after Total Thyroidectomy.