MON-471 The Broken Heart That Hid Behind the Goiter

Most goiters grow slowly over many years and are often asymptomatic. Although substernal goiters are estimated to represent between 5-24% of all mediastinal masses [1], a majority are benign. Symptoms may include neck fullness, nocturnal or positional dyspnea, or dysphagia due to tracheal and/or esophageal compression [2-3]. We present a case of a patient with new onset dyspnea that was initially attributed to a large intrathoracic goiter, but ultimately was found to be due to severe heart failure. A 72-year-old man with a history of HTN, type 2 diabetes, and moderate aortic regurgitation presented to his primary care physician with exertional dyspnea, dry cough, and bilateral leg edema for 2 months. He was referred to pulmonology and a chest CT showed a large intrathoracic goiter, measuring 8.5 x 4.6 x 5.3 cm, extending from the left limb of the thyroid into the mediastinum with rightward tracheal and leftward aortic arch displacement. The patient had no prior history of thyroid disease, cancer, or neck radiation. He denied neck fullness, dysphagia, positional or nocturnal dyspnea, though his exertional dyspnea was progressive. Labs revealed that the patient was biochemically euthyroid. Due to concern for malignancy, the patient underwent a biopsy via EBUS/bronchoscopy, which was non-diagnostic. The case was ultimately discussed at cardiothoracic tumor board, and it was determined that since the mass had likely been present for several years and with the surgical risks being high, to continue monitoring with serial imaging. At this point, the patient’s dyspnea and edema continued to worsen, and he was evaluated with an echocardiogram which showed a severe worsening of ejection fraction in just three months, from 53% to 5%, with global hypokinesis. He was started on diuretics and medical therapy with prominent improvement in his dyspnea. His cardiology team felt this acute decompensation was likely due to coronary artery disease and recommended left heart cardiac catheterization, however the patient declined. Goiters tend to be asymptomatic and grow slowly over time. Given their intra-thoracic location and ability to prominently deviate the mediastinum, it can be tempting to attribute respiratory symptoms to large substernal goiters. However, when a patient develops acute symptoms, one must always rule out alternative diagnoses. References 1. Priola AM, Priola SM, Cardinale L, Cataldi A, Fava C. The anterior mediastinum: diseases. Radiol Med. 2006;111(3):312 2. Katlic MR. Wang CA, Grillo HC. Substernal goiter. Ann thorac surg. 1985;39(4):391. 3. Benbakh M, Abou-elfadl M, Rouadi S, Abada RL, Roubal M, Mahtar M. Substernal goiter: experience with 50 cases. Euroepean annals of otorhinolaryngology, head and neck diseases. 2016-02-01, volume 133, issue 1, 19-22.