I had minor spotting while on Tamoxifen so my oncologist switched me to Arimidex. I've had a para-ovarian cyst for years that my ob/gyn has been watching via ultrasound with no suggestion that it needed to be biopsied.

6cm is larger than 2 inches, pretty large for an ovarian cyst. Find out what's going on and I pray you won't have another thing to worry about.

I never had spotting, but would sometimes get the "familiar" crampy feelings I used to get when i had my period before chemo thru me into menopause. I would suggest getting the biopsy just to be on the safe side, but most likely it is spotting related to just having the cysts I hope. I have a rather large one that will come out when they do my hysterectomy next year as it was unresponsive to oral therapy. It occassionally causes some pain, but it has never caused any spotting in me, but I haven't had a period since 2007 so maybe that is the difference?

Ive also had cramping and heavy periods on and off while taking tamoxifen..I had U/S and biopsy done..biopsy came back clear but I have polyps in uterus..Dr said most likely due to tamoxifen..Waiting to have procedure scheduled to remove polyps...Good luck to you..

I had a biopsy on the uterine wall, ob/gyn was concerned with the bleeding with tamoxifen. It only started a week ago. Now I'm just waiting for results, I'm going to end up having a hysterectomy just to be done with all of this.