Endocrine Abstracts

40years old lady with 12 months history of hyperthyroidism. Treated with ATD. Referred by her treating physician for RAI therapy due to intolerance to ATD and high dose requirement after 12 months. Patient being treated as Classical Graves’ Hyperthyroidism. She had symptoms of hyperthyroidism at time of presentation but none at time of assessment in our hospital. Main current issue was painful neck swelling: developed slowly over preceding two months. No problems with swallowing. No change in voice. Also intermittent itching: started when first started ATD, improved when given different tablet but remains troublesome. No eye symptoms. Examination revealed moderate, hard, diffuse, painful, non-vascular goiter. Thyroid uptake scan showed low uptake Tc99 uptake 1.5 % and ultrasound showed diffuse low echogenicity with reduced vascularity. Blood tests revealed extremely high Tg and TPO Abs Titers and low titer TRAb and very high Serum IgG4 level. Our patient converted to hypothyroidism shortly after a course of steroids. FNA cytology consistent with Hashimoto’s and IgG4 level improved with treatment. Our patient has hyperthyroidism caused by Hashimoto’s presenting with unusually prolonged Hashitoxicosis phase (12 months), Longest reported case in the literature is 5 months. Thyroid functional Conversion appears to be induced by steroids: Possibly affecting the dominating thyroid Ab type i.e Conversion from Stimulating to Blocking TSHRAbs. IgG4 Thyroiditis appears to responsive to steroids, may need further/ longer courses of GCs or may need Thyroidectomy.