Diagnosing a lump under the skin in the groin

I have had a marble(maybe a little smaller) sized lump in my groin(almost in the crease where the leg meets the groin, but more towards the groin) for about 2 years. It doesn't hurt unless I press on it and then it is sensitive. You can not see it, it is under the skin. There is no redness or warmth to it. It doesn't feel like it is movable.
I am assuming it is a swollen lymph node. I am just wondering if the fact that I have had it for awhile along with the other symptoms make it more or less likely that is is some type of cancer
.

If it were cancer would I have any other symptoms??

I also have had Ulcerative Colitis for 3 years, which causes a myriad of problems. You can get dehydrated which can lead to fevers, fatigue etc.. I had what I thought was a very bad flare up in September. I had fevers every day for about 6 weeks, night sweats, where my clothes would end up soaked, fatigue, exhaustion, lost about 6lbs, my left ankle became painful and swollen, I developed a red bump(size