Thigh Swelling & Fluid Collection After Injury: What Could It Be?

Question
A week ago, my son fell thru a deck. We were replacing rotten boards, but he found one before we could get it. He didn't break anything, but did get huge bruises on the outside and inside of his thigh. I did not take him to his dr, he seemed ok. The bruising is healing fine, however the outside of his thigh now has a large "lump". It feels like water or fluid. It is almost the size of a baseball. He has no pain. I have been reading online about injuries or trauma to the muscle or bruising the bone due to impact. This seems the same. Would wrapping it with an ACE bandage and a heating pad reduce the fluid? He has not stopped any activities either.  Should he see a Dr? Immediately? In a week or so? Thank you in advance, I'm looking forward to hearing from you!!

Kellie (mom)

Answer
It sounds like a Seroma.....   A bruise where the blood is being resorted but the fluid pocket remains..... Some will fade, some have to be drained and wrapped, some need minor surgery to close the new space down so fluid does not recollect.   Tere is no hurry for treatment..... I would give it a month, then get it looked at.  That is provided that it is not red, painful, infected.