Most breast lumps are benign (non-cancerous), as in fibroadenoma, a condition that mostly affects women under age 30. Fibrocystic breast changes occur in more than 60% of all women. Fibrocystic breast cysts change in size with the menstrual cycle, whereas a lump from fibroadenoma does not. While most breast lumps are benign, it is important to identify those that are not. See your health care provider if a lump is new, persistent, growing, hard, immobile, or causing skin deformities.
Review Date: 12/10/2012 Reviewed By: Robert A. Cowles, MD, Associate Professor of Surgery, Yale University School of Medicine, New Haven, CT. Review provided by VeriMed Healthcare Network. Also reviewed by A.D.A.M. Health Solutions, Ebix, Inc., Editorial Team: David Zieve, MD, MHA, David R. Eltz, and Stephanie Slon.