This 74 year-old female presented with mild dyspnoea. The chest x-ray above shows a superior mediastinal mass which displaces the trachea to the right. The margins of the mass fade out at the level of the clavicles, the cervicothoracic sign, indicating an anterior location. The most common anterior superior mediastinal mass is a retrosternal goitre, as in this case. Not all goitres are anterior – some may insinuate between trachea and oesophagus, in which case the margins are visible above the clavicles.
Other anterior mediastinal masses (thymic tumours, germ cell tumours) tend to be more caudad. Lymphadenopathy in lymphoma may be at the same level.
Reference: Gurney JW, Winer-Muram HT. PocketRadiologist Chest: Top 100 Diagnoses. Amirsys 2003Credit: Dr Laughlin Dawes