it could be a bud site sometimes buds form on the main stem/trunk a the start of the branch. If it looks like like a banana formation it's male but if it's it's leafy it's not! I been looking at it a couple times and it's probably male pollen sacs. Sorry! and in very mature plants sometimes you will find seed "sacs" forming on stems primarely on main stems. If there is no white hairs on your plant it's not good news!