Images in Endocrine Pathology: Thyrotoxicosis Associated with Destructive Thyroiditis

Abstract

A 49-year-old male had been diagnosed at birth with tricuspid atresia with ventricular and septal defects. He underwent multiple cardiac surgeries including a Glenn anastomosis and a modified Fontan procedure with a right atrium to right ventricle Carpentier–Edwards valve bioprosthesis. In a visit to the adult congenital cardiac clinic, he reported a 6–8-week history of increasing dyspnea on exertion, fatigue, swelling of the right leg, and intermittent tremor. The thyroid gland was of normal size. Laboratory investigation revealed thyrotropin less than 0.05 mIU/L (normal, 0.35–4.94 mIU/L), free T3 11.9 pmol/L (normal, 2.6–5.7 pmol/L), and free T4 77 pmol/L (normal, 9–19 pmol/L) consistent with thyrotoxicosis. No evidence of ophthalmopathy was noted. He was admitted for a therapeutic thyroidectomy.