What is a common cause of Superior Vena Cava Syndrome?

• A. Lung cancer causing compression of the superior vena cava
• B. Pulmonary embolism
• C. Bacterial pneumonia
• D. Lymphoma

Answer: (D)

Superior vena cava syndrome happens when the superior vena cava is blocked, most often by a mass in the mediastinum compressing it or invading its wall. Lymphoma frequently involves mediastinal lymph nodes and can rapidly enlarge a mass that directly presses on the SVC, making it a classic and common culprit. The obstruction prevents normal drainage from the head, neck, and upper extremities, leading to symptoms like facial swelling, plethora, headaches, and distended neck veins.

While lung cancer also commonly causes SVCS by external compression, lymphoma is a particularly well-recognized cause because mediastinal lymphadenopathy from lymphoma frequently forms a mass in this region, producing the characteristic obstruction. The other options don’t typically produce this pattern: a pulmonary embolism causes acute chest symptoms without SVC compression; bacterial pneumonia causes infection and consolidation rather than venous obstruction; a lung tumor can cause SVCS, but the mediastinal mass from lymphoma is more emblematic of this syndrome in many clinical contexts.