Vaginal cysts usually don't need to be treated. Often they will remain small and not cause any problems. Your health care provider may just want to monitor the cyst's growth during routine exams. You might need to have a biopsy of the cyst to rule out cancer. During a biopsy, your health care provider removes a piece of tissue from the cyst. That piece of tissue is examined under a microscope to see if it is cancerous.