I've had this lump for a few months now but never really thought about it as anything serious but I recently started wondering what it may be. It's a sort of lump under the skin on my left, hand side of my penis. It feels like veins, but it is circular. It remains the same size when my penis is flaccid and erect, there is a sort of bump or swelling where the lump is but it isn't greatly swollen and when my penis is erect the bump isn't as obvious.
It hasn't caused any pain, discomfort or any trouble at all. The lump is underneath my middle finger when I grip my penis and I wondered it possibly it could be a result of too vigerous masturbation or would be just an oddly shaped vein. I decided to look into it as I read that testicular cancer is more common in 15-35 year olds and any lumps don't always cause pain or side effects.
P.S. Im 15 years of age and a virgin.

The odds of random benign lumps are thousands of times higher than testicular cancer, but of course if you are worried you can have a doctor look. Also, testicular cancer would be confined to your testes. Men have lumps and bumps of all sorts of shapes and sizes, women have them too.

I was wondering if you could tell me what a doctor looks for when doing an examination, that way I could possibly do it myself?

My husband had a hernia in his testicles and he waited forever to get it checked out when he was a teenager because he was embarrassed and the problem just got worse and worse over time. Go get it checked out, it's most likely nothing, could be testicular cancer, a hernia which shouldn't go untreated, or something else. I know he regrets waiting... go get it checked out.

(You don't have a hernia on your penis, and you don't have testicular cancer there either.)

Doctors look at color, size, shape, softness/hardness, and whether it moves freely with the skin, independent of what is beneath it. They ask how long you have had it and if it has changed.

Again, men and women have countless bumps in soft sensitive areas that rub, don't get much exposure to air and light, and may be moist a lot, and not just the groin/pubic area - such as under breasts, near the rectum, and under arms, even pronounced folds around ears and eyes. I suspect that your observation about a clump of veins is correct.

Men and women do have countless bumps but I have to agree that seeing your doctor is the best way to go. Just because most bumps are harmless, doesn't mean that any bump you do discover shouldn't be checked out.

There's no way you can determine what this bump is by yourself. Nor can anyone on this site determine what the bump is. Only a doctor can tell you for sure.