I have severe swelling in the left side of my neck, in the clavical area. I had a central line several years ago. Could it be scar tissue from that? I also have pain in my left arm, left side of my chest, tingling,numbness in my left arm and hand. What could be causing this problem? The swelling also worsens if I sleep on my left side or do any activity with my left arm. There is no redness in the area, it isnt tender or painful to touch. But it looks like a huge lump on the side of my clavical about the size of a golf ball.