The two most common types of benign breast lumps are cysts and fibroadenomas. In addition, there are several other conditions that can present themselves as lumps, such as fat necrosis and sclerosing adenosis. A cyst is a fluid-filled sac, that develops in the breast tissue, which typically occurs in women between the ages of 35 and 50 and is most common in women approaching menopause. They often enlarge and become tender and painful just before the menstrual period and may seem to appear overnight. Cysts are rarely malignant and may be caused by a blockage of breast glands.
Cysts can feel either soft or hard.
When close to the surface of the breast, cysts can feel like a large blister, smooth on the outside, but fluid-filled on the inside. However, when they are deeply imbedded in breast tissue, a cyst will feel like a hard lump because is covered with tissue. Your physician may identify a lump as a cyst by physical examination, but many physicians confirm the diagnosis by mammography or ultrasound examination. The physician may then perform a fine-needle aspiration as the next step in diagnosing the cyst. This procedure involves guiding a very fine needle into the cyst and drawing fluid from it.