Below are different kinds of benign (non-cancerous) breast lumps.

COMMON BREAST LUMPS

Cysts
Fluid-filled sacs that tend to form and dissipate spontaneously within the breast tissue. They form when fluid from the glandular breast tissue is pushed out into a sac. By the appearance on ultrasound, the radiologist can determine whether or not the area is a cyst.

Fibroadenoma
This is the most common, solid, benign breast lesion. Approximately 76% of solid lesions with a benign appearance on mammogram or ultrasound are fibroadenomas. These most commonly occur in younger women. It is unknown why they occur. They may occur as a single lesion or they may occur in both breasts as a single or multiple occurrence.

A fibroadenoma is a solid lesion composed of fibrous and glandular tissue. It is affected by hormones and may enlarge during pregnancy. If the fibroadenoma is large or is interfering with a woman's breast self exams, she may wish to discuss surgical removal. Occasionally when fibroadenomas have been present for a long time, white specks may appear within the lesion. These are called calcifications. This merely indicates normal breakdown of the fibroadenoma as it ages.

Lymph nodes
Lymph nodes are small bean-shaped glands that vary in size; they are an important part of your immune system. Lymph nodes can be found alone or in groups in several areas of the body, including the under arm area; it is also normal to have lymph nodes within the breast. Lymph nodes can enlarge when there is inflammation or infection. When this occurs, they may feel painful or tender – this doesn’t always mean that there is something wrong, however, your health care provider may recommend a mammogram or an ultrasound to rule out a more serious condition. The radiologist can identify lymph nodes by their characteristic appearance. Enlarged or abnormal looking lymph nodes may need to be biopsied to ensure they are benign or a follow-up exam may be needed to ensure they return to their normal size over a period of time.

LESS COMMON BREAST LUMPS

Complex cysts
An area that has some of the features of a fluid-filled sac, but they may contain a solid component or thick fluid. An abscess (area containing pus from an infection) or hematoma (blood blister) fits into this category. These may require a follow-up ultrasound or an aspiration to try to remove fluid from the area or possibly a biopsy.

Seroma
A Seroma is a clear pocket of fluid which sometimes develops following a surgery; they can also be caused by injury. Depending on the size of the seroma, it may take up to a few weeks to resolve. Aspiration (draining) of the seroma may be needed for help in healing. Seromas may persist for several months or even years, with the tissue surrounding the seroma hardening over time. Seromas are benign and do not affect you breast cancer risk.

Sebaceous gland cyst or oil cyst (epidermal inclusion cysts)
Sebaceous glands secrete oil to lubricate hair and skin. They are located just under the skin’s surface and are connected to the skin’s surface by a tiny opening. Occasionally, this opening may become plugged causing the gland to become enlarged, inflamed or infected.

If the area is red and swollen, or if you notice a colored discharge, see your health care provider, as antibiotics may be needed to adequately resolve the symptom. If you continue to experience issues with a sebaceous cyst, you may be referred to a dermatologist or to a surgeon to have the cyst removed. Sebaceous cysts are benign (not cancer) and do not affect your breast cancer risk.

Fat Necrosis
Fat necrosis is a benign (non-cancerous) breast condition caused by the disruption of blood supply to the fat cells; it is usually caused by trauma to the breast or as a result of breast surgery. It feels like a firm, round lump(s) and is usually painless. It can form if an area of fatty breast tissue is damaged, it can occur anywhere in the breast and can affect people of any age. It does not increase your risk of getting breast cancer. Fat necrosis requires no treatment and often goes away by itself. If you have fat necrosis that causes you pain or discomfort, talk with your health care provider regarding treatment options.

Lipoma
Lipomas are a benign (non-cancerous) tumor or growth of fat cells. These are commonly found in adults age 40-60 and present as soft, usually moveable, painless lumps. These have a characteristic appearance on a mammogram. Treatment is usually not necessary unless the lump becomes painful or begins to restrict movement. Lipomas that grow very large may need to be biopsied to rule out other underlying conditions. Lipomas do not affect breast cancer risk.

Papilloma
A finger-like growth within a breast duct. These cause irritation to the inner lining of the breast duct and may cause clear or bloody discharge from the nipple. Some papillomas are seen by mammogram or ultrasound. Some are found from a biopsy of a lesion. The recommendation is to excise the entire papilloma and examine it under the microscope. Studies have shown a small percent of these prove to be a cancer. [Most studies show around 5%, some up to 20%]

Vague lumpiness or thickening
Glandular (fibrocystic) breast tissue, particularly in premenopausal women, can feel thicker or lumpier during a breast exam. If, on a mammogram or ultrasound, the area in question does not show anything other than normal breast tissue, the woman is referred back to her primary healthcare provider for follow-up and monitoring of the area.