that originates in milk ducts under the nipple but first appears on the skin.The term Paget disease also refers to an unrelated metabolic bone disease ( see Paget Disease of Bone Paget Disease of Bone Paget disease of bone is a chronic disorder of the skeleton in which areas of bone undergo abnormal turnover, resulting in areas of enlarged and softened bone. The breakdown and formation of... read more 
). These distinct diseases should not be confused with each other.
Paget disease of the nipple occurs mainly on the nipple and results from a cancer of the breast milk ducts that has spread to the skin of the nipple. Both men and women are affected. The underlying cancer may or may not be felt by the person or the doctor.
Sometimes Paget disease of the nipple develops in areas other than the breast (called extramammary Paget disease). It can develop in the groin or genital area or around the anus as the result of a cancer originating in underlying sweat glands or even in nearby structures such as the bladder, anus, and rectum.
Symptoms of Paget Disease of the Nipple
The skin in Paget disease of the nipple appears red, oozing, and crusting, similar to dermatitis Overview of Dermatitis Dermatitis is inflammation of the upper layers of the skin, causing itching, blisters, redness, swelling, and often oozing, scabbing, and scaling. Known causes include dry skin, contact with... read more but with a sharp border. Itching and pain are common.
Diagnosis of Paget Disease of the Nipple
Biopsy
Because Paget disease looks very much like common dermatitis, a biopsy Biopsy Doctors can identify many skin disorders simply by looking at the skin. A full skin examination includes examination of the scalp, nails, and mucous membranes. Sometimes the doctor uses a hand-held... read more 
is necessary to make the diagnosis. During this procedure, a small piece of skin is removed and examined under a microscope.
As with other cancers, once the diagnosis of Paget disease of the nipple is confirmed, doctors do an examination and tests to see whether the cancer has spread.
Treatment of Paget Disease of the Nipple
Treatment of the underlying breast cancer, including removal of the nipple and areola
For extramammary Paget disease, surgery or laser therapy
Paget disease of the nipple is usually treated like other types of breast cancer Treatment Breast cancer occurs when cells in the breast become abnormal and divide uncontrollably. Breast cancer usually starts in the glands that produce milk (lobules) or the tubes (ducts) that carry... read more , and the nipple and the area of pigmented skin around the nipple (areola) are surgically removed.
Paget disease outside the breast area is treated by removing the entire growth with surgery, drugs applied to the skin, radiation therapy Radiation Therapy for Cancer Radiation is a form of intense energy generated by a radioactive substance, such as cobalt, or by specialized equipment, such as an atomic particle (linear) accelerator. Radiation preferentially... read more , or laser therapy.
More Information
The following English-language resources may be useful. Please note that THE MANUAL is not responsible for the content of these resources.
American Cancer Society: Paget Disease of the Breast: Information about Paget disease of the nipple, including treatment options and prognosis
National Cancer Institute: Paget Disease of the Breast: Factual information about Paget disease of the breast, including prognosis and links to research and related resources
Susan G. Komen: Paget Disease of the Breast: A resource for all types of breast cancers, including links for breast health and support resources
