A woman in her 40s presented with progressive dyspnea and inability to lie flat. Two years prior to presentation, she had noticed a tender, firm thyroid enlargement associated with rapid weight gain. She was hypothyroid with a thyroid-stimulating hormone level of 15.42 mIU/L and a free thyroxine level of 0.95 ng/dL. (To convert free thyroxine to picomoles per liter, multiply by 12.871.) She was started on treatment with levothyroxine. Thyroid fine-needle aspiration revealed fibrosis and mixed inflammatory cells, and examination of core biopsy specimen showed sclerosis and chronic inflammation. She was followed closely by an endocrinologist and treated with maximal medical therapy over 2 years without improvement.
Danan D, Mo YD, Shonka DC. Neck Mass With Progressive Shortness of Breath. JAMA Otolaryngol Head Neck Surg. 2015;141(3):285-286. doi:10.1001/jamaoto.2014.3411