Which statement best describes SVC syndrome?

• A. It results from obstruction of the inferior vena cava.
• B. It causes decreased venous pressure in the upper body.
• C. It results in dilation of veins in the head, neck, and arms with potential cyanosis.
• D. It primarily affects the lower extremities.

Answer: (C)

SVC syndrome happens when the superior vena cava is obstructed, so blood from the head, neck, and upper extremities cannot drain properly. This raises venous pressure in the upper body, leading to visibly dilated superficial veins in the head, neck, and arms, as well as facial swelling and sometimes cyanosis if the blockage is significant. The description of venous dilation in the head, neck, and arms with potential cyanosis directly reflects this increased upstream venous pressure and the most characteristic signs of the condition.

The other ideas don’t fit because SVC syndrome is not due to obstruction of the inferior vena cava and does not cause decreased venous pressure in the upper body. It also does not primarily affect the lower extremities; the upper body is involved first and most prominently.