Definition

Paget's disease of the breast is a rare form of breast cancer which makes up approximately 1-4 % of all breast tumors. While sharing its name with Paget's disease of bone, these are two medically unrelated conditions. They are simply named after the same doctor who first described them.

  Description

Paget's disease of the breast is generally associated with an underlying breast cancer. It is generally seen in people between the ages of 40 and 80 years. Cases in men have been identified, but they are extremely rare.

Paget's disease of the breast may also be called mammary Paget's disease (MPD). There is a much rarer form of this disease called extramammary Paget's disease (EMPD). MPD affects the breast nipple and is also called Paget's disease of the nipple. EMPD can affect the skin of the external genital tissues in both women and men, as well as the skin of the eyelids and external ear canal. MPD is believed to develop from a tumor growth within the milk ducts of the breast. EMPD may represent a spreading (metastasis) of MPD to other parts of the body.

  Causes and symptoms

The cause of Paget's disease of the breast is unknown, but it is usually associated with an underlying cancer of the breast.

The symptoms of Paget's disease of the breast include:

• red scaly patches of skin on the nipple and sometimes also on the dark area of skin around the nipple (areola)
• crusting, bleeding, or ulceration of the skin of the affected area
• a discharge of fluid from the nipple
• a turning inward (inversion) of the nipple

In approximately 30-40 % of cases of Paget's disease of the breast, there is also a detectable lump in the breast.

  Diagnosis

Paget's disease of the breast is often confused with other skin conditions, such as eczema, dermatitis, or psoriasis. These misdiagnoses often lead to delays in appropriate treatment. Misdiagnosis is more common when both breast are affected and no lump in the breast is detected. When only one breast is affected, or when the presence of a lump in the breast is also detected, a correct initial diagnosis is more likely to occur.

Once Paget's disease of the breast is suspected, it can be definitively confirmed by biopsy of the affected tissue. In this procedure, a small piece of the affected skin and the underlying tissue is removed and sent to a laboratory for examination under a microscope. The shape and other characteristics of the cells in the biopsied sample will allow the laboratory personnel to determine if the sample is affected with Paget's disease of the breast, or some other condition.

Topical steroid creams are usually used to treat eczema, dermatitis, and psoriasis. These creams will have no effect on the skin conditions caused by Paget's disease of the breast.

  Treatment

Surgery is the main treatment for Paget's disease of the breast. Removal of the breast (mastectomy) may be recommended if the cancer is seen in a wide area away from the nipple or appears to be deep into the breast tissue. Breast conservation surgery, aimed at keeping as much of the breast as possible, may be recommended in cases where the disease is diagnosed early enough and the cancer has not spread far from the surface of the nipple.

Some people will require further treatment after surgery. This treatment may include radiation therapy, chemotherapy, or a combination of both. Radiation therapy involves using high-energy x rays to destroy any cancer cells that may remain after surgical removal of the primary tumor. Radiation therapy is most common after breast conservation surgery. Chemotherapy involves the use of medicinal drugs to destroy the growth of any cancer cells that may remain after removal of the primary cancer. Chemotherapy treatments are most common after mastectomy.

  Alternative treatment

Alternative treatments for Paget's disease of the breast include: the use of cartilage from cows or sharks; a diet known as Gerson therapy; administration of the chemicals hydrazine sulfate or laetrile; and, the injection of solutions derived from the mistletoe plant.

  Prognosis

The prognosis for Paget's disease of the breast depends on the underlying cancer that is causing this condition and whether or not this cancer has spread (metastasized) to other parts of the body.

  Prevention

Because the cause of Paget's disease of the breast is not known, prevention of this disease is not possible. In instances where this conditions arises from other underlying cancers of the breast, it may be possible to prevent Paget's disease of the breast from occurring if the underlying cause is diagnosed and successfully treated prior to the development of Paget's disease of the breast.

   Key Terms:

Metastasis The spread of a cancer from one part of the body (where the cancer originated) to another part of the body. Ulceration The formation of an ulcer, a patch of tissue that is discontinuous with the surrounding tissue because the tissue within the ulcer has decayed or died and been swept away.

   Resources:

Books

• Love, Susan M., and Karen Lindsey. Dr. Susan Love's Breast Book, 3rd edition. Reading, MA: Perseus Book Group, 2000.

Periodicals

• Desai, D.C., E.J. Brennan, Jr., and N.Z. Carp. "Paget's Disease of the Male Breast." American Surgeon 62 (December 1996): 1068-72.
• Kollmorgen, D.R. et al. "Paget's Disease of the Breast: A 33-year Experience." Journal of the American College of Surgeons 187 (August 1998): 171-7.
• Sheen-Chen, S.M. et al. "Paget Disease of the Breast - an Easily Overlooked Disease?" Journal of Surgical Oncology 76 (April 2001): 261-5.

Organizations

• American Cancer Society. 1599 Clifton Road NE, Atlanta, GA 30329. (800)ACS-2345. http://www.cancer.org.
• National Alliance of Breast Cancer Organizations. 9 East 37th Street, 10th Floor, New York, NY 10016. (888) 806-2226. Fax: 212-689-1213. http://www.nabco.org/.
• National Breast Cancer Coalition. 1707 L Street Northwest, Suite 1060, Washington, DC 20036. (800) 622-2838. Fax: 202-265-6854. http://www.natlbcc.org/

Other

• Paget's Disease of the Breast: The CancerBACUP Factsheet. http://www.cancerbacup.org.uk/info/paget.htm. (12 May 2001)
• Ruth, Laura. Paget's Disease: A Rare Form of Breast Cancer. http://users.cnmnetwork.com/~lrs1/paget.htm. (12 May 2001)