Understanding Breast Lumps - Benign and Cancerous

Not All Breast Lumps Are Cancer

Computer rendering of breast cancer
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During a breast self-exam, you may notice lumps or a change in breast texture — see your doctor if this is the case. While most breast lumps are not cancer, the only way to tell for sure is through further tests, like a mammogram and/or biopsy.

Let's take a closer look at cancerous breast lumps, as well as two common non-cancerous breast lumps- cysts and fibroadenomas.

Breast Cysts

This is a benign (harmless) fluid-filled sac, which can grow right within the breast tissue.

They are common and rarely linked to breast cancer. 

What Does a Breast Cyst Feel Like?

This breast lump will feel smooth and squishy. If you are pressing on a cyst, it will have some give to it, like a water balloon. A cyst can move around and can change in size during your menstrual cycle.

Where are Breast Cysts Located?

Breast cysts can be located near the surface, or deeper inside, close to your chest wall. If the cyst is closer to the surface, it is easy to find and easy to distinguish from other lumps. But if it is deeper inside, it's more difficult to distinguish it from other kinds of breast lumps, because when you press on it, you're actually trying to work through layers of breast tissue, which may be dense and firm.

How are Cysts Diagnosed?

Cysts cannot be diagnosed by a clinical breast exam or mammogram alone. Instead, a doctor will probably order a breast ultrasound — since the sound waves pass right through fluid-filled cysts, as opposed to bouncing back in solid lumps.

In the case of solid cysts, more tests, like a biopsy may be needed.

In the case of a fluid-filled cyst, a doctor may also take a sample of the cyst fluid by performing a fine needle aspiration with a syringe. This procedure removes the fluid from inside the cyst.  If the cyst deflates with aspiration, and the fluid is non-bloody, this is a benign breast cyst.


Breast Fibroadenomas

This is a benign tumor, consisting of glandular and connective tissue. That being said, while fibroadenomas are benign, they do increase a woman's risk of developing breast cancer in the future by one and a half to two times, according to the American Cancer Society. 

What does it feel like? This will feel like a round breast lump, and can be hard or firm. It can be moved around during a breast self-exam.

Where is it? These can be located near the surface of the breast and are easily felt.

Treatment: According to the American Cancer Society, many doctors recommend removal of fibroadenomas, especially if they are growing or altering a woman's breast shape. 

When does it appear? Fibroadenomas usually appear in women younger than 30, but they can appear in women of any age. They may occur during pregnancy. They are not common in post-menopausal women.

Other Benign Breast Lumps or Tumors (or Conditions)

According to the American Cancer Society, other benign breast conditions include:

  • Ductal or lobular hyperplasia
  • Lobular carcinoma in situ (LCIS)
  • Adenosis
  • Phyllodes tumors
  • Intraductal papillomas
  • Granular cell tumors
  • Fat necrosis and oil cysts
  • Mastitis
  • Duct ectasia
  • Radial scars
  • Lipomas or other benign tumors or lumps like hamartomas, hemangiomas, hematomas, adenomyoeptheliomas, and neurofibromas

Remember only a biopsy can distinguish between a cancerous lump or tumor versus a benign breast lump or tumor. Also, it's important to note that certain benign breast conditions — like papillomas or atypical hyperplasia — may increase a woman's risk of developing breast cancer in the future. 

Breast Cancer

What is it? A malignant lump that is made of abnormal breast tissue cells, growing in an uncontrolled way that may spread to the adjacent tissues or other organs.

What does it feel like? A malignant breast lump will have an irregular shape (not round) with a pebbly surface, somewhat like a golf ball. It will be very hard, like a slice of raw carrot. It may not be movable during a breast self-exam, but since tissue around it may move, it's sometimes hard to know if the lump is moving, or if healthy tissue around it is moving.

A clinical breast exam and a mammogram will help to clear up the diagnosis. A needle biopsy would provide more information about the lump and is the only way to distinguish between cancer and a non-cancerous condition.

Where is it? Breast cancer can be located near the surface, or deeper inside the breast, close to the chest wall. It can also occur in the armpit area, where there is more breast tissue.

Treatment: The lump itself may be treated with one or combined therapies: surgery, chemotherapy, radiation, and hormone suppression therapy. Talking with your doctor will help you decide on the best treatment plan for your particular diagnosis.

When does it appear? Breast cancer may appear in women who are pubescent, in their fertile years, peri-menopausal, or postmenopausal.

See what breast tumors look like on a mammogram.


American Cancer Society. (2015).  Non-Cancerous Breast Conditions: Fibroadenomas. 

American Cancer Society. (2014). For Women Facing a Breast Biopsy: Benign breast conditions: Not all lumps are cancer

BreastCancer.org. (2013). What Mammograms Show: Calcifications, Cysts, Fibroadenomas

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