I think I responded to another request of yours. I also had a "thickening" in my breast, but not under the nipple. It was accompanied by breast discharge, adn turned out to be a non-invasive, pre-cancerous condition called Ductal Carcinoma In Situ. I ended up having two lumpectomies, which still did not remove all of the offending tissue, and just 4 weeks ago had a simple mastectomy. I do not have to undergo chemotherapy or radiation, but if you end up having the same thing and you keep your breast, you may need radiation. A good resource is breastcancer.org if you have more questions. YOu can also call the National Cancer Institute or visit their Web site. They have great info.