Paget's Disease of the Nipple
Paget's disease of the nipple is a rare form of breast cancer in which the cancer forms in or around the nipple. In most cases, other forms of breast cancer are also present. Symptoms of this disease include redness, swelling, and scaly skin around the nipple area. Surgery is the most common form of treatment for the condition.
Paget's disease of the nipple, also called Paget's disease of the breast, is an uncommon type of cancer that forms in or around the nipple.
More than 95 percent of people with the disease also have underlying breast cancer; however, Paget's disease of the nipple accounts for less than 5 percent of all cases of breast cancer. For instance, of the estimated 211,240 new cases of breast cancer projected to be diagnosed in 2005, fewer than 11,000 were expected to involve Paget's disease of the nipple.
Most people diagnosed with Paget's disease of the nipple are over age 50, but rare cases have been diagnosed in people in their 20s. The average age at diagnosis is 62 for women and 69 for men. The disease is rare among both women and men.
Paget's disease of the nipple was named after Sir James Paget, a scientist who noted an association between changes in the appearance of the nipple and underlying breast cancer. There are several other unrelated diseases named after Paget, including Paget's disease of the bone and Paget's disease of the vulva.
Scientists do not know exactly what causes Paget's disease of the nipple, but two major theories have been suggested for how it develops.
One theory proposes that cancer cells, called Paget cells, break off from a tumor inside the breast and move through the milk ducts to the surface of the nipple, resulting in the disease. This theory is supported by the fact that more than 97 percent of people with Paget's disease of the nipple also have underlying invasive breast cancer or ductal carcinoma in situ (DCIS). DCIS, also called intraductal carcinoma, is a condition in which abnormal cells are present only in the lining of the milk ducts in the breast and have not invaded surrounding tissue or spread to the lymph nodes. DCIS sometimes becomes invasive breast cancer. Invasive breast cancer is cancer that has spread outside the duct into the breast tissue and possibly into the lymph nodes under the arm or into other parts of the body.
The other theory suggests that skin cells of the nipple spontaneously become Paget cells. This theory is supported by the rare cases of Paget's disease of the nipple in which there is no underlying breast cancer and cases in which the underlying breast cancer is found to be a separate tumor from the Paget's disease.