You are here

Benign Breast Lesions

Most breast lesions found will be benign, or non-cancerous, in nature. Whilst they may be detected as a palpable lump in the breast, whether through self-examination or clinical examination by a physician, often these lesions will be detected incidentally through mammography, ultrasound, or biopsy performed for another reason.

Localised nodularity

A localised nodularity, or lumpiness, is a common finding, particularly in young women, and is a reflection of normal physiological changes throughout the menstrual cycle.

Clinical monitoring for 2-3 months is typically sufficient for a cyclical and symmetrical nodularity in younger women, and ultrasound and mammography may be used in women over 30 years old or with asymmetrical nodularity. Close monitoring is important to identify enlarging masses.

Particularly in older women, fine needle or core biopsies may be considered, as, very uncommonly but importantly, some breast cancers may present as an area of localised nodularity.

Breast cysts

Breast cysts, or fluid-filled cavities, occur when the amount of fluid normally secreted in the milk ducts of the breast is greater than the amount absorbed. It is normal for breast cysts to vary in size at different stages of the menstrual cycle, or for them to come and go spontaneously.

Breast cysts can feel well circumscribed and smooth, and will be easy to move, and are commonly tender to feel. If the fluid inside the cyst is under pressure, the lump may feel more firm.

They are a very common finding on mammograms or ultrasounds, particularly in women aged 30-50 years, although they can occur in women of any age. Post-menopausal women taking hormone replacement therapy are more prone to developing cysts, due to the responsiveness of breast cysts to hormone levels.

Importantly, cysts are a benign condition, and there is no substantially increased risk of breast cancer in the future. Very rarely, “intra-cystic” cancer may be present, although these cancers will produce cysts that are clearly abnormal in appearance and on aspiration.

The decision of whether or not to treat a lump that has features of a typical, well-defined cyst is partly dependent on the woman’s preferences, although often they will be drained in order to reduce pain and discomfort. Small cysts generally are not palpable, and do not require treatment.

Treatment involves simple aspiration with a needle, and the fluid inside is commonly watery and straw-coloured.

Surgery is not typically recommended unless the cysts are recurrent after repeated drainage or if there are any worrying features. Cysts may come back after weeks or months, or new cysts may develop in the surrounding tissue.

Any new lump should always be examined by your doctor. It is easy for women who frequently develop cysts to become complacent about new breast lumps, and this may delay the diagnosis of breast cancer.


Fibroadenomas are overgrowths of tissue supporting the breast and cells lining the milk ducts, and are a very common benign breast condition. The vast majority occur in young women, particularly in the 21-25 year old age bracket.

A palpable fibroadenoma is generally round or oval-shaped, smooth and firm or rubbery, and very freely moveable.

The diagnosis of fibroadenoma can be confirmed through core biopsies, often using ultrasound guidance. If the lesion is particularly small on ultrasound and unable to be biopsied , follow up ultrasounds may be recommended instead.

Fibroadenomas can be removed surgically, or can be managed without surgery, particularly in younger women. If the lump is greater than 3cm in diameter, painful, growing or shows concerning features, surgical removal is often recommended.

Fibroadenomas do not cause cancer, and cancer is no more likely to develop within the lump than anywhere else in the breast.

Fat necrosis

Trauma, whether accidental or surgical, can produce an area of fat necrosis, or dead fat, that presents as a palpable lump. This will typically feel firm and non-painful, and the surrounding skin may look red, bruised or even dimpled.

Fat necrosis can be very difficult to distinguish from malignant breast tumours on imaging, and so biopsy may be recommended. It is a benign condition, and does not increase the risk of developing breast cancer.


Adenosis refers to the enlargement of lobules in the breast, and an increased number of glands within these lobules. It is a condition often found on biopsy in women with fibrocystic changes, although, if many enlarged lobules are close together, a lump may be felt on self-examination or by your doctor.

Adenosis is not a form of cancer, although it may appear similar to breast cancer on mammography due to areas of microcalcification. A biopsy is typically performed to confirm the diagnosis.

Sclerosing adenosis, a special type of adenosis where scar tissue forms in and distorts the enlarged lobules, is associated with an increased risk for developing breast cancer in future, by a factor of 1½ to 2 times.