Malignancy - Related SVC Syndrome

S uperior vena cava (SVC) syndrome is an uncommon entity that affects approximately 15,000 Americans per year. Symptoms result from near or complete obstruction of the SVC and include facial and upper-extremity edema, chest pain, cough, dyspnea, dysphagia, proptosis, cyanosis, and headache. The severity of these symptoms relies upon the degree of SVC compression and the location of the obstruction relative to the azygous vein or other potential routes of collateralization.1-7 Although 5% to 20% of SVC syndrome cases arise as a result of fibrosis after thrombosis or the presence of indwelling catheters, the majority of cases are caused by malignancy. Lung cancer accounts for 65% to 85% of malignant SVC syndrome, and the remaining cases are secondary to lymphoma, mediastinal masses, tumors of the breast, mesothelium, thyroid, thymus, esophagus, or other rare malignancies. It is estimated that 3% to 15% of patients with lung cancer and 5% to 20% of patients with intrathoracic malignancy develop SVC syndrome.5,7-13 In contrast to SVC syndrome of nonmalignant etiology, malignancy-related SVC syndrome is usually progressive, and prompt treatment is often critical. Quality of life is dramatically affected with SVC syndrome. With malignant causes, SVC syndrome typically evolves over a course of 2 to 4 weeks. In nonemergent cases, palliation of symptoms is usually the goal. SVC syndrome becomes a medical emergency, and prognosis suffers if serious cerebral edema develops or if laryngeal edema compromises airway patency.5