My son has a lump on his right shin which is soft and slightly movable there was a very small bruise which has gone,he only told me about it a couple of days ago and said he has had it ages. Im very worried about it and trting to tell myself it could be a ganglion or cyst. I had a ganglion on my rt ankle as a child and cysts do run in my family. He has had alot of bangs on his legs when playing football at school.