Whether it's a vascular formation (which sounds frightening because it isn't normal) or thyroid nodule you need an ultrasound to check it out. Insist that your doctor refer you for a thyroid ultrasound with flow study (to see where the blood flow is).
In most cases, a lump that moves is better news than a hard, stationary lump. However, it wouldn't hurt to have an ultrasound just to be sure, so ask your doctor to order one. If he refuses, ask him to refer you to someone else.
Good luck to you!
Papillary Thyroid Cancer
First diagnosed 1985
From what I have read, when it moves up and down when swallowing, it is on the thyroid because the thyroid moves when you swallow. My fairly large nodule moves when I swallow too. I have had ultrasound and biopsy - still awaiting results. Check it out with someone else. You need an ultrasound just to make sure.Good Luck. :)