I might be able to help you. I have lymphadema in my right leg. The doctors have no idea what caused it. It came on suddenly when I was 28 years old (on my honeymoon). Five years later I got divorced, but I still have the lymphadema.

There is very little to do to treat this, but at least for me, I do not have any pain and I have learned to live with it. If you need more info, let me know. Good luck.
Mark