- Obstruction of the superior vena cava results from mediastinal mass lesions.
- Features include a plethoric and cyanosed face with periorbital oedema, exophthalmos, conjunctival injection, and venous dilatation in the fundi, distended non-pulsatile neck veins and a positive Pemberton sign.
- lung cancer (90%)
- retrosternal tumours e.g. lymphoma, thymoma, dermoid
- retrosternal goitre
- massive mediastinal lymphadenopathy
- aortic aneurysm