The information on this page was reviewed and approved by
Maurie Markman, MD, President, Medicine & Science at CTCA.

This page was updated on April 2, 2021.

Rare breast cancer types

Rare breast cancers differ from other types of breast cancer in their signs and symptoms. They also vary by outlook and treatment regimens.

Inflammatory breast cancer

Inflammatory breast cancer (IBC) is a rare type of breast cancer often starts in the soft tissues of the breast and causes the lymph vessels in the skin of the breast to become blocked. As a result, the breast may become firm, tender, itchy, red and warm due to increased blood flow and a build-up of white blood cells. This type of cancer is distinct from other types, with major differences in symptoms, prognosis and treatment.

The term “inflammatory” refers only to the appearance of the breasts. When breasts become inflamed due to an infection or injury, they often become tender, swollen, red and itchy. However, the underlying cause of IBC is unrelated to inflammation.

Because of the similarities in symptoms, IBC may at first be diagnosed as a breast infection, such as mastitis. However, although antibiotics will resolve a breast infection, they cannot treat IBC. If your doctor prescribes antibiotics and your symptoms do not resolve within seven to 10 days, this may be a sign that you have IBC.

IBC tends to grow quickly and aggressively and is typically diagnosed when it is already in an advanced stage, most often stage IIIB or stage IV.

Inflammatory breast cancer treatment options: Treatment of inflammatory breast cancer typically includes chemotherapy, followed by surgery (breast-conserving surgery or total mastectomy) and radiation therapy. Additional therapy, such as hormone therapy and/or additional chemotherapy, may also be given. Learn more about advanced treatments for breast cancer.

Metastatic breast cancer

Metastatic breast cancer, also known as stage IV or advanced breast cancer, is breast cancer that has spread to other organs in the body. Metastases from breast cancer may be found in lymph nodes in the armpit, or they can travel anywhere in the body. Common sites include distant organs like the lung, liver, bone and brain. Even after an original tumor is removed, microscopic tumor cells may remain in the body, which allows the cancer to return and spread.

Patients may initially be diagnosed with metastatic disease, or they may develop metastases months or years after their initial treatment. The risk of breast cancer returning and metastasizing varies from person to person and depends greatly on the biology of the tumor and the stage at the time of the original diagnosis.

Treatment for metastatic breast cancer includes many of the same treatments as other stages of breast cancer:

  • Chemotherapy
  • Hormone therapy
  • Radiation therapy
  • Targeted therapy
  • Surgery

These treatments may be given alone or in combination.

Learn about metastatic breast cancer

Male breast cancer

Male breast cancer occurs when malignant cells form in the tissues of the breast. Any man can develop breast cancer, but it is most common among men who are 60 to 70 years old. About 1 percent of all breast cancers occur in men. About 2,000 men are diagnosed with breast cancer each year.

Many men may be surprised to learn they can get breast cancer. Men have breast tissue that develops in the same way as breast tissue in women and is susceptible to cancer cells in the same way. In girls, hormonal changes at puberty cause female breasts to grow. In boys, hormones made by the testicles prevent the breasts from growing. Breast cancer in men is uncommon because male breasts have ducts that are less developed and are not exposed to growth-promoting female hormones.

Just like in women, breast cancer in men may begin in the ducts and spread to surrounding cells. More rarely, men may develop inflammatory breast cancer or Paget’s disease of the breast, if a tumor that began in a duct beneath the nipple moves to the surface. Male breasts have few if any lobules, and so lobular carcinoma rarely, if ever, occurs in men.

Men should also be aware of gynecomastia, the most common male breast disorder. Gynecomastia is not a form of cancer but does cause a growth under the nipple or areola that can be felt, and sometimes seen. Gynecomastia is common in teenage boys due to hormonal changes during adolescence, and in older men, due to late-life hormonal shifts. Certain medications can cause gynecomastia, as can some conditions, such as Klinefelter syndrome. Rarely, gynecomastia is due to a tumor. Any such lumps should be examined by your doctor.

Male breast cancer treatment typically consists of mastectomy, followed by radiation therapy, chemotherapy, hormone therapy and/or targeted therapy. Since many male breast cancers are hormone receptor-positive, the drug tamoxifen (Nolvadex®) is often a standard therapy for male breast cancer.

For men whose cancer has not spread to the lymph nodes, adjuvant therapy (therapy given after surgery) is generally the same as for a woman with breast cancer. For men whose cancer has spread to the lymph nodes, adjuvant therapy may include chemotherapy plus tamoxifen and/or other hormone therapy. Treatment for men with cancer that has spread to other parts of the body may include hormone therapy and/or chemotherapy.

Paget's disease of the breast

Paget’s disease of the breast is a form of breast cancer that causes distinct skin changes on the nipple. A rare disease, accounting for fewer than 3 percent of all breast cancers, it is named for Sir James Paget, the English surgeon who first documented the condition in 1874. Under a microscope, Paget’s cells look very different from normal cells, and divide rapidly. About half of the cells test positive for estrogen and progesterone receptors, and most test positive for the HER2 protein. Although women with Paget’s disease of the breast sometimes have tumors inside the breast tissue, its most noticeable symptoms involve changes to the skin of the nipple or areola (the darker, circular area around the nipple of the breast), creating oozing or the appearance of eczema. The cancer is typically diagnosed with a biopsy of the tissue, sometimes followed by a mammogram, sonogram or MRI to confirm the diagnosis. Paget’s disease of the breast is not related in any medical way to other conditions named after Sir James Paget, such as Paget’s disease of the bone.

The main symptoms of Paget’s disease of the breast are superficial skin changes, limited to the nipple or areola, that are sometimes mistakenly dismissed as innocuous. Those symptoms include:

  • A skin rash on the nipple or areola, resembling eczema, with the skin developing flakiness, redness or itchiness
  • Discharge from the nipple
  • A burning, painful or tingling sensation, especially in advanced stages of the disease
  • Nipple changes, such as inverted nipples
  • Changes to the breast, such as a lump, redness, oozing, crustiness or a sore that doesn’t heal

The primary treatment for Paget’s disease of the breast is most often the surgical removal of the tumor. Cancers that are diagnosed in the early stages may be treated with breast-conserving lumpectomy, while more advanced malignancies may require a mastectomy.

As with other breast cancers, your care team may recommend chemotherapy, radiation therapy or other treatments for Paget’s disease of the breast. Learn more about advanced treatments for breast cancer.

Papillary carcinoma

In papillary carcinoma, the cancer cells are arranged in finger-like projections, or papules. Under a microscope, the cells appear fern-like.

Papillary carcinoma is a rare type of breast cancer, accounting for about three percent of all breast cancers. Papillary carcinoma typically has a better prognosis than other, more common breast cancers.

The primary difference between papillary carcinoma and other types of breast cancer is that the cancer cells are arranged in finger-like projections, or papules. Under a microscope, the cells appear fern-like. Sometimes, the cancer cells are very small in size, in which case the cancer may be called micropapillary.

Most papillary carcinomas are invasive and are treated like invasive ductal carcinoma. However, invasive papillary carcinoma usually has a better prognosis than other invasive breast cancer. Most often, invasive papillary carcinoma occurs after the development of noninvasive papillary carcinoma.

Papillary carcinoma may also be detected when it is still noninvasive. Noninvasive papillary carcinoma is usually considered a variety of ductal carcinoma in situ (DCIS). In its earliest stages, when the cancer cells are just beginning to affect the ducts, this disease may be referred to as infiltrating papillary carcinoma.

Treatment for papillary carcinoma often consists of a combination of surgery, radiation, chemotherapy, hormone therapy and/or therapy that targets the HER2 protein.

Next topic: What is metastatic breast cancer?