In female breast cancer, lumps are usually found near the armpit. In male breast cancer, lumps are usually found near the nipple. Most lumps in the breast are noncancerous, but it’s still important to seek medical attention if you find one.

Finding a breast lump is cause for concern, but it may help to know that most breast lumps aren’t cancerous.

In fact, around 80% of breast biopsies are benign and reveal that a person doesn’t have breast cancer.

For those who do have breast cancer, the most common location of the primary tumor is the upper outer quadrant of the breast. Of course, breast cancer can start anywhere there’s breast tissue.

Read on to learn more about where breast cancer lumps are found and what to do if you find one.

According to a 2017 study, research has repeatedly shown that the upper outer quadrant of the breast is the most common site of breast cancer occurrence. That would be the part of your breast nearest the armpit.

It may help to visualize each breast as a clock with the nipple at the center. Facing your right breast, the upper outer quadrant is in the 9:00 to 12:00 position. Facing your left breast, the upper outer quadrant is in the 12:00 to 3:00 position.

Find more information about breast cancer here.

illustration showing the quadrants of the breastsShare on Pinterest
Illustration by Wenzdai Figueroa

The reason more breast cancer lumps occur in the upper outer quadrant isn’t clear, but the area does have a lot of glandular tissue.

A 2019 study analyzed data on people who’d been diagnosed with female breast cancer between 2010 and 2013.

The researchers found that those with tumors located near the periphery of the breast (including the upper outer quadrant) had better outcomes than those with tumors located near the nipple.

People with male anatomy usually only have small amounts of breast tissue in the area under or around the nipple. As a result, male breast cancer lumps are usually located near the nipple.

The upper outer quadrant and the nipple are not the only places breast cancer can start, though.

Parts of the breast

The breasts comprise connective tissue, glands, ducts, and fat.

Breast tissue takes up a large area. It covers the pectoral muscles and extends from the breastbone to the armpit and up to the collarbone.

Female breasts have 15–20 lobes or sections. Lobes comprise lobules, and the glands that produce milk are located at the ends of lobules. Milk travels from the lobules to the nipple through the ducts.

People with male anatomy have fewer lobules and ducts.

All cancers start when cells begin to grow out of control, which can happen in any part of the breast.

Most breast cancers begin in the ducts. Cancer that begins in the ducts is also known as invasive ductal carcinoma.

Breast cancer can occur just under the skin or deep within the breast near the chest wall, where it’s difficult to feel.

Fibrocystic changes

Sometimes, fibrous breast tissue, mammary glands, and ducts overreact to the hormones your body produces during ovulation.

These lumps typically increase in size and sensitivity in the days leading up to your menstrual period. This cycle may repeat throughout your reproductive years and gradually come to a stop after menopause.

Cysts

Cysts are fluid-filled lumps or bumps appearing anywhere under the skin, including within the breast. In breast cysts, fluid fills the lobules.

Breast cysts are typically located in the upper outer quadrant or the central margins (in the middle, close to the nipple).

Breast cysts are usually benign and may not require treatment unless their size or presence bothers you.

Simple cysts, which are only filled with fluid, do not increase your risk of developing breast cancer, according to the American Cancer Society (ACS).

Fibroadenomas

These lumps aren’t typically tender, though soreness is possible before menstruation. Fibroadenomas are generally moveable. You will likely feel the lump move when you apply gentle pressure to the area.

Papillomas

Papillomas are wart-like bumps that develop in the lining of your mammary ducts near your nipple. Clear or bloody discharge is possible. However, papillomas usually aren’t cause for concern.

Malignant tumors

Malignant or cancerous lumps are also possible, albeit much less common than other breast-related conditions.

These lumps will continue to grow until they’re removed. During this time, the cancer can spread to other areas, like the lymph nodes. Early diagnosis and treatment can help improve the overall outlook.

Breast cancer lumps have certain characteristics that may differentiate them from noncancerous lumps.

Keep in mind that these are generalizations. A lump is not something you should try to diagnose on your own. Doctors can’t always tell by touch alone, either.

Here are some signs that a breast lump may be cancerous:

  • It doesn’t hurt.
  • It’s firm or hard.
  • It’s bumpy.
  • It has irregular edges.
  • You can’t move it with your fingers.
  • It’s growing or changing.

Having one or more of these characteristics does not mean you have breast cancer.

Breast cancer lumps can sometimes present very differently. They can be soft, moveable, and painful. They can also occur anywhere on the chest or armpit.

Cancerous breast lumps are similar for people with female breast cancer and people with male breast cancer.

A breast lump is the most common symptom of breast cancer. However, breast cancer can also appear as an area of thickened tissue or skin rather than a distinguishable lump.

Some types of breast cancer, such as inflammatory breast cancer, may not cause a lump at all.

Statistics from the Centers for Disease Control and Prevention (CDC) reveal that there are about 240,000 new cases of breast cancer among U.S. women each year and about 2,100 among U.S. men.

Each year, about 42,000 women and 500 men in the United States die from the disease.

That’s why it’s important to have a doctor examine lumps that develop anywhere on your chest or underarms.

Noncancerous breast disease is more common than breast cancer among people with female anatomy.

There are many kinds of breast disorders, many of which present with a breast lump.

Here are some signs that a breast lump may not be cancerous:

  • It’s tender, or it hurts.
  • It feels soft or rubbery.
  • It’s smooth and round.
  • You can easily move it using the pads of your fingers.
  • It’s getting smaller.

What to do if you feel a lump

Finding a breast lump can be upsetting, even if you know that most breast lumps aren’t cancerous. Because breast cancer is easier to treat before it spreads, it’s important to seek a diagnosis.

Here’s what to do if you feel a lump:

  • Consult a healthcare professional: First things first, call a primary care medical professional or gynecologist if you have one. If you don’t have a doctor you see regularly, contact a doctor’s office or clinic in your area. Make it clear that you’ve found a lump in your breast and you need a clinical exam.
  • Remember that a physical examination may not give you the answer: The doctor may also need to order a mammogram, an ultrasound, or an MRI. That doesn’t mean you have breast cancer.
  • Try to remain calm: Remind yourself there’s a good chance that the lump is benign. You’re being proactive and doing the right thing by having it checked out.
  • Follow up with the doctor’s office or clinic: Contact the doctor’s office or clinic to get your test results, understand what they mean, and find out what your next steps are.
  • Prioritize your own health: Be persistent and diligent — if you can’t get an appointment or your concerns aren’t fully addressed, seek out another doctor.
Was this helpful?

In people with female anatomy, breast cancer lumps are usually found in the upper outer quadrant of the breast. In people with male anatomy, they’re usually found near the nipple.

Most breast lumps turn out to be something other than breast cancer. Even so, localized female breast cancer is highly treatable.

Based on data collected between 2013 and 2019, localized female breast cancer has an overall 5-year relative survival rate of 99.3%.

This means that people with female breast cancer are almost as likely to live for another 5 years as people without female breast cancer.

You can help catch breast cancer before it spreads by familiarizing yourself with how your breasts normally look and feel. One way to do this, particularly if you have a higher-than-average breast cancer risk, is to perform a breast self-exam.

If you discover a lump or notice other changes in the way your breasts look or feel, contact a doctor right away.

At your appointment, you should learn about recommendations for screening, your personal risk factors, and other breast cancer warning signs.