SAT-512 Thyrotoxicosis Followed by Hypothyroidism Post Total Laryngectomy and Hemithyroidectomy

Abstract BACKGROUND: Thyrotoxicosis has been described in few case reports after non thyroid neck surgeries but only in one case report after total laryngectomy and hemithyroidectomy. Subacute lymphocytic thyroiditis has been reported in one case post thyroid lobectomy in a patient with thyroid cancer. Total thyroidectomy or lobectomy are common practice as a part of laryngeal cancer treatment. Clinical Case: 57- year old male with history of laryngeal cancer was admitted for total laryngectomy, bilateral neck dissection, left hemithyroidectomy. Post-operative Day 3 patient reported feeling anxious and palpitations. On exam he had tachycardia up to a heartrate of 150s/min. His baseline TSH, FT4 and Ft3 were all normal one week before the surgery. On the 5th day after the surgery, TSH was undetectable, FT4 was 3.3(range 0.71 - 1.48), while FT3 was normal 2.66 (range 1.71 - 3.7). Thyroglobulin were high (range 2.8 - 40.9) while Thyroglobulin antibodies, anti TPO and TRAB were all normal. Thyroid US was not done because of technical difficulties given the patient neck surgery. The patient had Burch-Wartofsky Point Scale of 35 at that time. He was started on a beta-blocker and heart rate improved to 110-120. Over the next 5 days his FT4 Improved and was normal by day 10 after the surgery. His TSH and Ft4 showed hypothyroidism 6 weeks after the surgery and levothyroxine was started. He was seen 4 months after the surgery with high TSH concerning for medication noncompliance. Conclusion: On our review of literature this would be the second case report of a thyrotoxicosis after total laryngectomy and hemithyroidectomy. Unique to our case is the devolvement of hypothyroidism after the initial phase of thyrotoxicosis resolved while in the other case reported in literature the patient did not develop hypothyroidism. Subsequent hypothyroidism in our case could be from underlying subacute lymphocytic thyroiditis or secondary to hemithyroidectomy. Reference: 1. Blenke EJ, Vernham GA, Ellis G. Surgery-induced thyroiditis following laryngectomy. The Journal of laryngology and otology. 2004;118(4):313-4. 2. Choi YS, Han YJ, Yeo GE, Kwon SK, Kim BK, Park YH, et al. Subacute lymphocytic thyroiditis after lobectomy in a patient with papillary thyroid carcinoma: a case report. Journal of medical case reports. 2013;7:3.