7046 Thyroid Storm After Thyroidectomy Without Underlying Hyperthyroidism

Abstract Disclosure: A.J. White-Cotsmire: None. B. Kodali: None. C. McHenry: None. M. Rahhal: None. Background: Thyroid storm is a feared complication of total thyroidectomy; however, this is a rare phenomenon seen primarily in patients with undiagnosed or poorly controlled thyrotoxicosis from Graves’ disease. Preoperative treatment of patients with hyperthyroidism with beta-adrenergic blockers and anti-thyroid medication to ensure that patients are euthyroid prior to thyroidectomy have largely eliminated this risk of thyroid storm. (1) We report a case of thyroid storm caused by release of preformed thyroid hormone, following extensive manipulation and resection of a large retrosternal nontoxic multinodular goiter. To our knowledge, this has not yet been previously described. Clinical Case: A 57yo female underwent a total thyroidectomy with resection of a large benign multinodular goiter with retrosternal extension, which was causing compressive symptoms. She had a nodular goiter for 7 years that was increasing in size. Fine needle aspiration 2 years prior to surgery demonstrated colloid and adenomatoid nodules with Hurthle cell changes. She had no history of hypo- or hyperthyroidism. TSH prior to surgery was 0.576µIU/ml (normal = 0.450-5.330µIU/ml). Extensive manipulation was required to deliver the goiter from beneath the manubrium. Pathology from her thyroid revealed a multinodular goiter without evidence of malignancy. Post-operative course was uncomplicated, and after an overnight stay, the patient was discharged home with 150mcg (1.5mcg/kg) levothyroxine daily. She presented to the emergency department 4 days later and was admitted to the intensive care unit with diffuse abdominal pain, nausea, vomiting, and myalgias, and she was diagnosed with atrial fibrillation with rapid ventricular response. TSH on admission was 0.020 µIU/ml, thyroglobulin levels were >2,250.0ng/mL (n=0.8 – 48.0 ng/mL), thyroglobulin antibodies were negative. Her levothyroxine was stopped, her heart rate was controlled with metoprolol, and she was started on oral anticoagulation with rivaroxaban. She was discharged after a 7-day hospital stay. At 3 weeks follow-up her TSH was 35.67µIU/ml and her thyroglobulin levels were 23.9ng/mL. Her symptoms had resolved, and levothyroxine was resumed at a lower dose of 137mcg daily. Six weeks later her TSH level was 7.785µIU/ml, and her thyroglobulin was 1.8ng/mL. Conclusion: To our knowledge, this is the first case of thyroid storm reported following thyroidectomy in a patient with nontoxic multinodular goiter in a clinically and biochemically euthyroid patient. Massive increase in thyroglobulin postoperatively and rapid resolution of symptoms suggest that the release of preformed thyroid hormone related to vigorous thyroid manipulation was likely the cause. Reference: (1) Christou N, Mathonnet M. Complications after total thyroidectomy. Journal of Visceral Surgery. 2013;150(4):249-256. doi:10.1016/j.jviscsurg.2013.04.003 Presentation: 6/1/2024