This has been present for the past 3 years and this has not changed in appearance , is this correct?
At this point, I do not think this is something that you need to worry about. This may be a sweat gland or a cyst and may likely be benign. All the other differentials or conditions you have posted do not seem to fit your condition. Pearly penile papules appear as a ring of white papules along the foreskin. A yeast infection may present with redness and itchiness.
I do suggest however that you have this checked by your primary physician or a dermatologist for an initial assessment.
Do you have any other similar lesions in other parts of the body?
Is this bump itchy ?
No, I don't have similar lesions anywhere on the body. And it is not itchy or any redness present.
What I can recall is one time, my top part (head of the penis) got stuck in the zipper. But then it should disappear over the time. This doesn't seem the case.
How can I make sure that it is a sweat gland or a cyst and may likely be benign.
Follow up to the post:
The small pimple / bump is on the head of the penis. Does this change anything.