My 16-year-old son has a hard painless lump about an inch above his left knee and slightly towards the interior. The skin above it looks fine. The lump is large. He has had it every since he can remember but never told anyone.
When he first told me I searched and searched to try and figure out what it was while waiting to get into see a doctor. I am posting this because I know what it is now, but I never came across the answer when I was searching and I want to help out others who may also be searching for hard painless lump on leg.
His bump was diagnosed as osteochondroma which is a benign condition. The lump is hard because it's bone - not a mass, not a lipoma. It was diagnosed with an x-ray. More males get it than females and it's usually dx between ages 10-20. It's just excess bone growing in the wrong direction and can happen in other areas too with other bones. The femur is the most popular.