<s>[INST] One breast has an abnormal nipple (inverts or appears flat when I stoop over) and I am wondering if scar tissue from multiple biopies could cause this.  Also, this has been like this for a few years.  The radiologist reported "abnormal nipple" at my recent mammogram. Also, there was a cyst revealed at a previous mammogram and ultrasound.  Nothing was done to this cyst.  It was just left there. [/INST] HelloWelcome to healthcaremagicInverted nipple can be due to so many different causes.This includes congenital,trauma ,infection caner etc. Although breast cancer is one of the cause of nipple invertion,it is not the only cause.Since your mammogram was done recently and it doesnot show anything abnormal you can be assured that it is not serious. Plastic surgery can be done if you opt to correct it.But you need to have your mammogram routinely as prescribed to follow your nipple and cyst.Regards </s>