Suggest Treatment For Cyst On Vaginal Wall

I had a pap smear and ultra sound done 8 weeks ago, in which they fund a cyst on my vaginal wall by the entrance of the cervix. My pap results were normal, and the cyst came back a simplecyst, but my gynecologist had a follow up ultra sound done and saw that it shrunk in size but it now has an internal echo. What is it? Or what should I do?