Swelling of the face and arms
A swollen thymus may press on the neck and adjacent superior vena cava (SVC). SVC is one of the largest veins in the body that carries blood back to the heart from the head and arms. This can cause the blood in the veins to “pool,” or “back up.” Pooling of blood in the SVC due to pressure put by swollen thymus is called SVC syndrome.
The common signs of SVC syndrome include swelling of the face, upper chest, back, and arms. Sometimes, it may also cause a bluish-red discoloration of the skin. If it affects the brain – symptoms can also include headaches, dizziness, and a change in consciousness. The SVC syndrome can be life-threatening, so it requires urgent treatment.