On occasion, a deer antler will have a "bulge" in one of the tines. (see pic below because I don't know how to explain it) I've also seen the same deer with several of these on different tines. What causes this?

See picture here: http://www.tndeer.com/tndeertalk/ubbthreads.php?ubb=showflat&Number=2942842&page=1#Post2942842