I'm a 35 year old male. On two occassions, I have had a temporary (3days first time, 1day second time) swelling on my penis, the size of a large almond, right below the head on the left side of the shaft. The first time, the swelling occurred the morning after having received a prolonged lap dance. I visited a urologist on the 3rd day (minimal swelling remaining) who said this was due to trauma from the dance. The second time (one month later), it happened morning after dry humping followed by protected sexual intercourse. Both times, I have seen a hard cord-like vein right where the swelling was. The cord was more visible in the beginning of each episode, after which there was diffuse swelling in the area. The swelling was whitish / yellowish (not like a bruise). In between episodes, I was tested for HIV, HSV2, IgG,IgM,VDRL,HCV,HepB, & TPHA -- all negative. I was not tested for Chlamydia or Gonorrhea. There is no discharge or pain. There were however 3 lesions diagnosed as lichen planus by my dermatologist (one lesion in the same area as the swelling) -- I used Elidel cream for 2 weeks and lichen are gone. I have not told my urologist about the lichen; and did not tell the dermatologist about the swelling problem. I have also been on long-term lowdose doxycycline for acne (could this be medicine allergy reaction?).
The swelling has not happened after masturbation, but only after the only 2 times that I have had prolonged sexual activity. It looks like a lymphocele based on my Web research, but my urologist doesn't think so because it went away so quickly. He doesn't want to induce erection with a needle because I'm young / unncessary pain. He said if it happens again I should see him immediately so he can see the swelling.
What does this sound like? Is it dangerous to induce the swelling again by myself (perhaps through masturbation)? Should I insist on an ultrasound (will this be dangerous / hurt)? Any help?? Quite concerned.