A 38-year-old man presents with facial and upper extremity edema, venous distention in the neck and arms and a cyanotic appearance. The following is/are true statement(s):

e. If the etiology is benign disease, gradual improvement without operation is to be expected

Although mediastinal granulomatous disease is one cause of the superior vena cava syndrome described, the most common cause (75%) is malignant disease. A venogram adds little information to the typical findings and increases risk from extravasation of contrast medium subcutaneously from the venous hypertension. Mediastinoscopy can be used for diagnosis with recognition of increased risk of bleeding and airway problems from the edema associated with the endotracheal intubation required for the procedure. If a malignancy is found, operative resection is usually precluded by the extent of mediastinal invasion. Fortunately, in the case of benign disease, the symptoms tend to improve with time as chest wall and mediastinal collaterals enlarge.