I have a ring of hard nodules under the skin on the shaft of my penis, just below the head. These nodules began forming in 2003 - first there was one, then half a ring, and now a nearly complete ring (except it doesn't completely encircle the penis; the underside of the shaft is nodule-free). The nodules are small, hard, painless lumps, and the skin slides right over them. Sometimes they disappear and reappear over the course of several days; originally they were only rarely present, but now they are almost always present. There are no nodules, discoloration, bumps, or any other oddity anywhere else on the penis.
Do you have any idea what this could be?
Thanks!