Any idea what this mark on my child is?

[Isitmybathtimeyet]

My son has this on his back. Says it doesn't hurt or itch. I haven't noticed it before tonight. The centre has a lump in it which he doesn't mind me pressing.

Is it just a bruise? Not come across one that had a palpable lump in it before!

Looks like a normal bruise to me, should start to change colour over the next few days.