Suggest Treatment For Uterine Fibroid

I am a 48 year old woman, not in menapause yet. I'm 5'8", weigh 150lb and battle cervical cancer 25 years ago and won. My gynecologist sent me to get a sonogram because she felt my uterus was enlarged and wanted to see if there was anything thats 's might contribute to my urinary incontinence. I received the result of the sonogram and it stated there's a 4cm lesion in the uterus adjacent to the endometrium most consistent with a fibroid. Impression: Uterine fibroid. Can you explain this to me, please. Is a 4cm lesion big?