When you go to the doctor, if you have questions, make sure you get the answers you need. If you don't feel like they've explained what something is, ask. You are paying them for their explanations. You can also call them and let them know that you didn't totally understand the diagnosis, and ask if someone can go over it with you.
Maybe it's a Tyson gland?
https://www.healthline.com/health/bumps-on-head-of-penis
You really should call and ask, though. Since you've had it examined, the doctor will be able to answer better than we can here. If you have questions about what the doctor says, we can help with that.
I have gone through almost a similar problem and when I consulted my doctor, he said it is part of skin allergy. Do you feel any kind of itchiness around it?
Over the years since late teens to adulthood, I had a small bump on the top third of my penis, just left of center. If I asked a doctor, I did not recall any concern.
I first thought it was maybe a wart. I squeezed the area and of the side white "crud" like dry substance cane out. I think that there may have been a very small opening there that collects crud or dirt or skin and after awhile it build up.
I just squeezed it like a pimple and it produced the small hole where everything came out.*
We are talking miniscule. It would build up and I would squeeze it over the years. After 30 years or so, I have not noticed it anymore.
*I can't tell if this is internally produced or external with a small hole that collects stuff. I sense it may be the latter.
Hope this helps, my sense is that it is not life threatening, however keeping yourself clean is necessary. I was not sexually active at the rime that I first noticed this, so I do not think it is from that. Not sure about it being a wart.
Stay safe.