Merck Manual

Please confirm that you are a health care professional

honeypot link

Breast Masses (Breast Lumps)


Mary Ann Kosir

, MD, Wayne State University School of Medicine

Last full review/revision Sep 2020| Content last modified Sep 2020
Click here for Patient Education
Topic Resources

The term breast mass is preferred over lump for a palpably discrete area of any size. A breast mass may be discovered by patients incidentally or during breast self-examination or by the clinician during routine physical examination.

Etiology of Breast Masses

  • Fibrocystic changes

  • Fibroadenomas

Fibrocystic changes (previously, fibrocystic disease) is a catchall term that refers to mastalgia, breast cysts, and nondescript masses (usually in the upper outer part of the breast); these findings may occur in isolation or together. Breasts have a nodular and dense texture and are frequently tender when palpated. The breasts may feel heavy and uncomfortable. Women may feel a burning pain in the breasts. Symptoms tend to subside after menopause.

Fibrocystic changes cause the most commonly reported breast symptoms and have many causes. Repeated stimulation by estrogen and progesterone may contribute to fibrocystic changes, which are more common among women who had early menarche, who had their first live birth at age > 30, or who are nulliparous. Fibrocystic changes are not associated with increased risk of cancer.

Fibroadenomas are typically smooth, rounded, mobile, painless masses; they may be mistaken for cancer. They usually develop in women during their reproductive years and may decrease in size over time. Juvenile fibroadenoma, a variant, occurs in adolescents, and unlike fibroadenomas in older women, these fibroadenomas continue to grow over time. Simple fibroadenoma does not appear to increase risk of breast cancer; complex fibroadenoma may increase risk slightly.

Breast infections (mastitis Mastitis Mastitis is painful inflammation of the breast, usually accompanied by infection. Fever later in the puerperium is frequently due to mastitis. Staphylococcal species are the most common causes... read more ) cause pain, erythema, and swelling; an abscess can produce a discrete mass. Infections are extremely rare except during the puerperium (postpartum) or after penetrating trauma. They may occur after breast surgery. Puerperal mastitis, usually due to Staphylococcus aureus, can cause massive inflammation and severe breast pain, sometimes with an abscess. If infection occurs under other circumstances, an underlying cancer should be sought promptly.

Galactocele is a round, easily movable milk-filled cyst that usually occurs up to 6 to 10 months after lactation stops. Such cysts rarely become infected.

Cancers of various types can manifest as a mass. About 5% of patients have pain.

Evaluation of Breast Masses


History of present illness should include how long the mass has been present and whether it comes and goes or is painful. Previous occurrence of a mass and the outcome of its evaluation should be queried.

Review of systems should determine whether nipple discharge is present and, if present, whether it is spontaneous or only in response to breast manipulation and whether it is clear, milky, or bloody. Symptoms of advanced cancer (eg, weight loss, malaise, bone pain) should be sought.

Past medical history should include risk factors for breast cancer, including previous diagnosis of breast cancer, history of radiation therapy to the chest area before age 30 (eg, for Hodgkin lymphoma). Family history should note breast cancer in a 1st-degree relative (mother, sister, daughter) and, if family history is positive, whether the relative carried one of the inherited gene mutations that predispose to breast cancer (eg, BRCA1, BRCA2).

Physical examination

Examination focuses on the breast and adjacent tissue. The breast is inspected for skin changes over the area of the mass, nipple inversion (retraction), and nipple discharge Nipple Discharge Nipple discharge is a common complaint in women who are not pregnant or breastfeeding, especially during the reproductive years. Nipple discharge is not necessarily abnormal, even among postmenopausal... read more Nipple Discharge . Skin changes include erythema, rash, exaggeration of normal skin markings, and trace edema sometimes termed peau d’orange (orange peel).

The mass is palpated for size, tenderness, consistency (ie, hard or soft, smooth or irregular), and mobility (whether it feels freely mobile or fixed to the skin or chest wall).

The axillary, supraclavicular, and infraclavicular areas are palpated for masses and adenopathy.

Red flags

Certain findings are of particular concern:

  • Mass fixed to the skin or chest wall

  • Stony hard, irregular mass

  • Skin dimpling

  • Matted or fixed axillary lymph nodes

  • Bloody or spontaneous nipple discharge

  • Thickened, erythematous skin

Interpretation of findings

Painful, tender, rubbery masses in women who have a history of similar findings and who are of reproductive age suggest fibrocystic changes.

Red flag findings suggest cancer. However, the characteristics of benign and malignant lesions, including presence or absence of risk factors, overlap considerably. For this reason and because failure to recognize cancer has serious consequences, most patients require testing to more conclusively exclude breast cancer.


Initially, physicians try to differentiate solid from cystic masses because cysts are rarely cancerous. Typically, ultrasonography is done. Lesions that appear cystic are sometimes aspirated (eg, when they cause symptoms), and solid masses are evaluated with mammography followed by imaging-guided biopsy Diagnosis Breast cancer most often involves glandular breast cells in the ducts or lobules. Most patients present with an asymptomatic mass discovered during examination or screening mammography. Diagnosis... read more Diagnosis . Some physicians evaluate all masses with needle aspiration; if no fluid is obtained or if aspiration does not eliminate the mass, mammography followed by imaging-guided biopsy is done.

Fluid aspirated from a cyst is sent for cytology only under the following circumstances:

  • It is turbid or grossly bloody.

  • Minimal fluid is obtained.

  • A mass remains after aspiration.

Patients are reexamined in 4 to 8 weeks. If the cyst is no longer palpable, it is considered benign. If the cyst has recurred, it is reaspirated, and any fluid is sent for cytology regardless of appearance. A third recurrence or persistence of the mass after initial aspiration (even if cytology was negative) requires biopsy.

Treatment of Breast Masses

Treatment of a breast lump is directed at the cause.

A fibroadenoma is usually removed if it grows or causes symptoms. Fibroadenomas can usually be surgically excised or, if < 3 cm, cryoablated after patients are given a local anesthetic, but fibroadenomas frequently recur. Patients who have fibroadenomas that are not excised should be checked periodically for changes. After patients have had several fibroadenomas established as benign, they may decide against having subsequent ones excised. Because juvenile fibroadenomas tend to grow, they should be removed.

Acetaminophen, nonsteroidal anti-inflammatory drugs (NSAIDs), and athletic bras (to reduce trauma) can be used to relieve symptoms of fibrocystic changes. Evening primrose oil may be somewhat effective.

Key Points

  • Most breast masses are not cancer.

  • Clinical features of benign and malignant disease overlap so much that testing should usually be done.

Click here for Patient Education
NOTE: This is the Professional Version. CONSUMERS: Click here for the Consumer Version
Professionals also read
Test your knowledge
Management of Normal Delivery
Options for pain management during normal delivery include regional, local, and general anesthesia. Of these types of anesthesia, which of the following is a safe and simple method for uncomplicated spontaneous vaginal deliveries in women who wish to bear down and push?
Download the Manuals App iOS ANDROID
Download the Manuals App iOS ANDROID
Download the Manuals App iOS ANDROID
Download the Manuals App iOS ANDROID
Download the Manuals App iOS ANDROID
Download the Manuals App iOS ANDROID

Also of Interest

Download the Manuals App iOS ANDROID
Download the Manuals App iOS ANDROID
Download the Manuals App iOS ANDROID