Epididymis Cyst

About 4-5 years ago I had a Vasectomy.  About two years ago I noticed a lump near the upper part of the right testicle.  My Urologist recommended I have an ultrasound evaluation.  I had that evaluation in January of 2007.  It showed the following:

The right epididymis maintains a cyst measuring 1.7 x 1.0 x 1.4 cm.  The testicles and epididymides show symmetric and appropriate blood flow.

As a precautionary measure I spoke with my family doctor about this during a recent routine visit.  I was concerned that the cyst may be getting larger.  He suggested another ultrasound.  I had this done today and saw that the cyst grew to about 2.5 cm.  My doctor is not going to be able to review my results for a week.  Since I am very concerned about this and I am asking if these circumstances lead one to believe this is likely to be a malignancy?  For the past week, I have been experiencing a small amount of discomfort starting in the scrotal area and going up, but I don’t know if that’s because I am thinking so much about my situation.