Endocrine Abstracts

Retrosternal goitres usually present with long-standing compressive symptoms or overt thyroid dysfunction. This case describes an unusual dual presentation: a respiratory-led pathway to diagnosis (CATCH protocol) and the unexpected presence of bilateral exophthalmos with negative TSH receptor antibodies. These features prompted further diagnostic evaluation and highlight the need for early multidisciplinary team (MDT) involvement. A 74-year-old male was referred to respiratory services with a persistent dry cough. Chest radiography demonstrated mediastinal widening, and CT imaging revealed a large multinodular goitre with retrosternal extension causing critical upper tracheal narrowing. He was initially clinically euthyroid then early thyroid function tests (TFT’s) showed biochemical evidence of thyrotoxicosis. Symptoms progressed to exertional dyspnoea, reduced voice volume, facial congestion, and a positive Pemberton’s sign. Examination revealed bilateral exophthalmos. Repeat TFT’s every 6 weeks demonstrated biochemical thyrotoxicosis (TSH 0.02, FT4 28.9, T3 10.3) with negative TRAb, raising the possibility of euthyroid Graves’ orbitopathy or atypical thyroid-associated orbitopathy. Subsequently, carbimazole was initiated but discontinued due to adverse effects. With progressive airway compromise (tracheal lumen 7 mm), antithyroid therapy was re-introduced to optimise thyroid status ahead of surgical intervention. Lung function tests were carried out by the respiratory team to demonstrate the clinical impact of airway compromise. To further complicate this, he had a history of previous sternotomy for cardiac surgery requiring the cardiothoracic team to evaluate the risks of re-sternotomy for goitre excision. This case highlights the importance of recognising thyroid pathology in patients presenting through respiratory pathways and demonstrates how exophthalmos with negative TRAb can complicate diagnostic interpretation. It also underscores the complexity of managing retrosternal goitres in patients with previous sternotomy, where early multidisciplinary involvement is essential. This case provides valuable learning from initial detection in a primary care setting to an MDT involving various medical specialties.