Good to hear it's not life-threatening or anything. A friend of mine fell from her bike and hit her elbow pretty hard. It didn't break, bruised like hell of course, but later she developed a lump that just kept growing. Later found out it had caused a rupture or something in the bone that caused it to start growing, so it was a calcified cyst I think they called it. It was approaching that same size (tennis ball) when they removed it. Crazy how our bodies can react to trauma like that. Take care. Drink plenty of beer, but don't walk around after.