Hard white bump on shaft of penis when erect

When my penis is flacid, you can't see it. But when erect, I have a hard white lump underneath the skin on the shaft of my penis. It isn't movable. It didn't used to be painful, but has gotten slightly larger and is now mildly painful. I've had it for years and just didn't think anything of it. What can it be?

[Bhupinder Kaur, MD]

Hello,
It can be a sebaceous cyst. Sebaceous cyst is filled with a soft, whitish brown material that sometimes oozes out onto the skin's surface. This material is called sebum. Get it examined from a dermatologist. You can also get a FNAB done. FNAB is aspiration of the material of the lump which is done by a fine gauge needle (22 or 25 gauge) and a syringe.

It is very difficult to precisely confirm a diagnosis without examination and investigations and the answer is based on the medical information provided. For exact diagnosis, you are requested to consult your doctor. I sincerely hope that helps. Take care and please do keep me posted on how you are doing.