Parathyroidectomy-Induced Thyroiditis

Presentation Number: SAT-0549
Date of Presentation: June 21st, 2014

Buthaina Almahmeed*1 and Catherine Mary Kelly2
1University of Toronto, Toronto, ON, Canada, 2Women's Coll Hosp, Toronto, ON, Canada

Abstract

Abstract: Parathyroidectomy-Induced Thyroiditis

Background: Parathyroidectomy-induced thyroiditis is a transient complication that is thought to be due to surgical manipulation of the thyroid gland during more extensive parathyroid surgeries. It appears histologically as a multifocal granulomatous folliculitis. It is under-appreciated mainly because the majority of patients are asymptomatic, and our case represents one of six similar cases published in the literature.

Case: A 70 year old lady with no prior history of thyroid disease underwent parathyroidectomy for primary hyperparathyroidism in July 2013. Three parathyroid glands were removed. The surgical procedure was uncomplicated and she was discharged the next day with normal calcium and PTH levels. She presented three days later to a community hospital emergency department with a headache and peri-orbital numbness. Her calcium level was normal at 2.28 mmol/L but TSH was found to be suppressed at <0.02 mIU/L, with a free T4 of 59 pmol/L. She was assessed in the endocrinology clinic two weeks later and her free T4 was declining, suggesting a diagnosis of parathyroidectomy- induced thyroiditis. She was managed conservatively and treated with propranolol for symptom control. Free T4 normalized four weeks later reaching a level of 12 pmol/L, with a TSH of 0.32 mIU/L. Her most recent free T4 and TSH levels were performed on August 28, 2013 and were 13 pmol/L and 3.67 mIU/L, respectively.

Conclusion: Parathyroidectomy may lead to a transient, taumatic thyrotoxicosis. Biochemical thyrotoxicosis can be associated with clinical symptoms of varying severity. It is a self-limiting condition but symptomatic treatment may be needed until the thyrotoxic phase resolves. Because clinically significant thyrotoxicosis can occur, patients undergoing parathyroidectomy should be informed of this potential complication.

 

Nothing to Disclose: BA, CMK