I had a ganglion on my hand about 10 years ago, I saw the doctor, who promptly hit it with a ruler, I was shocked!! he explained that sometimes a sharp whack would get rid of it, seemed a bit drastic to me, but I thought it would be worth it if it worked, it didn't sadly, the ganglion kept getting larger, and I found that I was catching it in doorway and cupboard doors more and more as it grew larger which made it quite painful, I also didn't feel comfortable about it being there, folks used to ask what it was, the doctor referred me to a specialist and I had a small op to repair it, I was told that it was fluid that was leaking from my wrist joint, all went well, I was told that they can return sometimes, but my hasn't thankfully, I just have a small hairline scar which is hardly noticeable, if it bothers you, ask your GP to refer you and get it sorted.
Hope this helps M