The majority of these benign lesions are not associated with an increased risk of breast cancer. It usually disappears after menopause unless estrogen-replacement therapy is used. Lumps are usually on both sides. Solitary lumps may occur, but multiple lumps are common. Lumps may be accompanied by generalized breast pain, especially before menstrual periods.
Lumps often enlarge before menstrual periods and shrink afterward.
Lumps come in different sizes. When the lumps are relatively large and near the surface, they can be moved freely within the breast. Family history of cysts is common. Some studies indicate that drinking coffee and smoking cigarettes are associated with a higher incidence and greater extent of fibrocystic breasts. Other studies have failed to show them as risk factors.