PENIS BUMP

Hello everyone. I've noticed a cylindrical bump ACROSS the right side of penis shaft, an inch or so in diameter. Its not as prominent when flaccid. When erect, it feels like a big vein, because it feels hollow when pressed on, although it has the same color as the skin. No pain, no swelling, no discoloration, ulcers, pimples etc. and penis is straight. What could it be? I accidentally noticed it a week ago and i honestly cant tell if i had it before and for how long. Thanks!

its hard to tell you what it could possibly be without a picture

George, you have no idea whatsoever how it got there - no rough games of any kind or pressure being applied to the penis when erect, stuff like that?
What it could be is a penile cyst - most of these are round rather than cylindrical however.
The only safe thing to do is to get it checked by a Medical Professional - should it be a cyst it will not go anywhere for 5 to 9 months or so, that is if it is not irritated further, or on a regular basis.
Best to be safe, get it checked …