depeinding on the size of the bulge, it could be a benign fatty tumor called a lipolma. i had one the size of a quarter removed from my arm a few months ago.
they can be much bigger and much smaller than that, though.
the one i had was painful to press against, so it had to be removed, otherwise as long as it isn't growing, it isn't a major problem
i am assumming you have either ruled out cancer, or are having a test for that soon
other than that, i can't help