Lump in Breast: 7 Causes & BI-RADS Explained

A lump in breast tissue is a small mass that is often caused by a benign condition, such as a cyst, fibroadenoma, fibrocystic changes, or lipoma. However, some breast lumps can be linked to infections or breast cancer and may need further evaluation.

A lump in breast tissue may feel firm, tender, movable, or painless, depending on the cause. Changes in breast size or shape, nipple changes, or a strong family history of breast cancer may increase concern and should be assessed by a healthcare provider.

Tests such as a breast ultrasound or diagnostic mammogram can help identify the cause of a lump in breast tissue and determine whether a biopsy is needed. Treatment depends on the diagnosis and may range from monitoring or cyst aspiration to cancer treatment when a malignant lump is confirmed.

Possible causes

Some of the most common causes of a lump in the breast include:

1. Fibrocystic breast changes

Fibrocystic breast changes are a common cause of breast lumps and are related to hormonal changes. They may be more noticeable during the menstrual cycle or while using certain hormonal medications.

Characteristics: The lumps may become more noticeable during the week before a menstrual period and improve after the period ends. They may feel firm or tender and can occur in one or both breasts. Read more about fibrocystic breast disease and how to manage symptoms.

2. Simple cysts

Breast cysts are more common in premenopausal women, particularly between ages 35 and 50. They are usually benign and rarely require treatment unless they cause symptoms.

Characteristics: Cysts can occur in one or both breasts and may change in size during the menstrual cycle. They may also become painful or tender, and some people report more discomfort after consuming caffeine, although the relationship between caffeine and breast cyst symptoms is unclear.

3. Fibroadenoma

A fibroadenoma is one of the most common types of benign breast lumps in younger women, particularly between ages 20 and 40. It develops from an overgrowth of glandular and connective breast tissue.

Characteristics: Fibroadenomas are usually round or oval, firm or rubbery, and can move easily under the skin instead of staying fixed in one place. They generally do not cause pain.

4. Lipoma

A lipoma develops from an overgrowth of fatty tissue in the breast. It is benign and usually does not require treatment, although it may sometimes be surgically removed if it causes discomfort or for cosmetic reasons.

Characteristics: Lipomas are generally soft and may feel like small pads of fatty tissue that move under the skin. However, some lipomas may feel firmer and can resemble other types of breast lumps.

5. Breast infections

Breast infections, such as mastitis, can cause inflammation of breast tissue and ducts and may lead to a lump. Mastitis is especially common during breastfeeding.

Characteristics: Breast infections usually cause pain or tenderness, especially when the affected area is pressed. Redness, warmth, and swelling may also occur.

6. Diabetic mastopathy

Diabetic mastopathy is a rare, benign breast condition that causes dense fibrous tissue to develop in the breast. It occurs most often in people with long-standing diabetes, particularly women with type 1 diabetes, and can resemble breast cancer during a physical exam or on imaging tests.

Characteristics: Diabetic mastopathy usually causes one or more hard, irregular, painless lumps that may occur in one or both breasts. Because these lumps can resemble breast cancer, additional testing and sometimes a breast biopsy may be needed to confirm the diagnosis.

7. Breast cancer

Breast cancer can sometimes first appear as a lump in the breast. It may also cause other changes, such as changes in the color, size, or shape of the breast or nipple, nipple discharge, skin changes, or persistent itching of the breast or nipple.

According to the American Cancer Society, the most common symptom of breast cancer is a new lump or mass, although most breast lumps are not cancer.

Characteristics: A breast cancer lump is often painless, hard, irregularly shaped, and may feel different from the surrounding breast tissue. However, breast cancer lumps do not always have these characteristics.

Main tests

The main imaging tests used to evaluate a breast lump are breast ultrasound and a diagnostic mammogram, depending on factors such as age and the characteristics of the lump. A healthcare provider will also perform a breast exam and may order additional tests when needed.

According to the American College of Radiology, imaging findings are reported using the BI-RADS system, which classifies results into categories from 0 through 6:

• Category 0: The exam is incomplete, and additional imaging or comparison with previous exams is needed.
• Category 1: Negative result, with routine screening recommended.
• Category 2: Benign findings, with routine screening recommended.
• Category 3: Probably benign findings, with a 2% or lower likelihood of malignancy. Short-term follow-up imaging, often after 6 months, is generally recommended.
• Category 4: Suspicious findings, with a greater than 2% but less than 95% likelihood of malignancy. A biopsy is generally recommended.
• Category 5: Findings highly suggestive of malignancy, with a 95% or higher likelihood of cancer. A biopsy is recommended to confirm the diagnosis and guide treatment.
• Category 6: Breast cancer has already been confirmed by biopsy.

A hypoechoic breast lump or hypoechoic nodule is a description that may appear on an ultrasound report. The term describes how the area appears on ultrasound and does not, by itself, indicate whether the lump is benign or malignant.

Treatment options

Breast lumps often do not need treatment, especially if they are benign, do not cause symptoms, and are not getting larger.

If a lump is painful or very large, a healthcare provider may recommend treatment based on the cause. This may include medication to relieve symptoms or aspiration to drain a fluid-filled cyst.

If the lump is cancerous, treatment is planned by a multidisciplinary healthcare team, which may include a medical oncologist, breast surgeon, pathologist, and radiation oncologist. The treatment plan depends on factors such as the type and stage of breast cancer and the patient’s overall health.

Breast lump in men

A breast lump in a man can have benign or malignant causes. Gynecomastia, which is an increase in male breast gland tissue, is one possible benign cause.

Any new or unexplained breast lump in a man should be evaluated by a healthcare provider. Testing can help determine the cause of the lump and rule out breast cancer.