Fibrocystic breast condition: a common condition characterized by lumpiness in one or both breasts due to the presence of multiple small cysts and masses. Fibrocystic breast condition is benign and is not a type of breast cancer. The condition affects more than 60% of women and is most commonly found in women between the ages of 30 and 50. Some women with the condition may experience symptoms like breast tenderness and breast pain. The development of fibrocystic breast condition is believed to be related to the normal hormonal variation during the menstrual cycle. The lumps found in the breasts can sometimes mimic the symptoms of breast cancer, or they may mask the symptoms of cancers.
Kasper, D.L., et al., eds. Harrison's Principles of Internal Medicine, 19th Ed. United States: McGraw-Hill Education, 2015.