IgG4-Related Hashimoto's Thyroiditis of the Thyroid Gland

Abstract

Immunoglobulin (Ig) G4-related Hashimoto's thyroiditis is a newly discovered subtype of Hashimoto's thyroiditis and characterized by thyroid inflammation and marked fibrosis. IgG4-related Hashimoto's thyroiditis is very rare and there has been relatively little information available to date. A 46-year-old woman with a past history of thyroid dysfunction visited our outpatient clinic for severe anterior neck swelling. She complained of swallowing discomfort and pain due to severe goiter and was successfully treated with total thyroidectomy. Immunohistochemistry showed thyroid invasion by IgG4-positive cells and an IgG4/IgG ratio over 40%. The patient was diagnosed with IgG4-related Hashimoto's thyroiditis. We report a very rare case of IgG4-related Hashimoto's thyroiditis with severe goiter. A more comprehensive understanding of the IgG4-related Hashimoto's thyroiditis may help physicians to allow proper diagnosis and treatment of patients with severe goiter.

Review of IgG4-related Hashimoto Thyroiditis With Best Practice Recommendations for Diagnosis and Reporting

“…Our patient's symptoms due to mass effect (dysphagia, airway obstruction) rather than chemical insult (eg, heat or cold intolerance, tremors, changes in energy level, etc.) align with reports of Luiz et al, 14 Kang et al, 16 and Zhao et al 18 in which neck swelling without symptoms of thyroid dysfunction were observed. Indeed, Li et al 1 found 39% (11/28) of IgG4-RHT cases to be associated with subclinical hypothyroidism.…”