Hi, my 12 yr old son with Aspergers has shown me a large deep purple bruise approx. 4 inches wide, kinda oblong shaped and has had it since this last Friday...approx. 5-6 days since I've been aware of it. I mention his Aspergers only because he says no injury, can't remember falling, someone hitting,kicking him, etc...He wold definitely tell me ..tends to obsess on littlest scratches...Bruise shows no sign of yellowing or green like it's healing...it is tender to touch, and there was a small lump under it when he showed it to me Friday evening and now lump feels larger and hard. It's located to the left of his belly button. The bruise starts approx. five inches to the left. As I said, it's approx. 4 inches wide and about 2 inches "tall".... should I be concerned or is it just something to watch?