I have a lump in my hamstring, its about the size of a golfball, however, not ROUND like that. If you cut a golfball in half thats about
as high as it sits off my leg. more long on the inside part of my hamstring tendon area.

It is not sore, has never been a bruise, and can only be felt when I flex my leg. If it were a mass, I'm sure i'd feel it when not
flexing, and it seems the harder I flex, the harder the bump gets... like its a muscle? It's only on my right leg, not left. It's
pretty noticeable tho.

I went for an ultrasound, they said there is no mass there that can be seen in an ultrasound.

Any ideas?

I have another appointment for a specialist in September. I read an article on irregular muscle growth.. Seems like its a possibility.