Cysts may be single or multiple. They are not seen as cysts on mammography, just as a dense mass or masses. If the radiologist suspects the mass is a cyst, an ultrasound is performed to see if there is fluid inside the mass. If there is, this is called a breast cyst. The next step is to determine if the breast cyst has more benign characteristics or could it possibly be malignant.
Fibrocystic changes are mostly thickened areas of the breast glands and supporting fibrous tissue.
The breast normally is composed of mostly fatty tissue. The glands and ducts are only a small part of the breast unless they undergo fibrocystic change or are stimulated by pregnancy. Fibrocystic change is much more a fibrous than cystic but some cysts can occur. Cysts can occur on their own or in a setting of fibrocystic change and when they do, they present more as a discrete mass you can get your fingers around. Fibrocystic change alone is a diffuse, rubbery thickening without any areas containing much fluid.