Paget's disease is a rare type of carcinoma that appears as a unilateral eczematous to psoriasiform plaque surrounding the nipple. It involves extension to the epidermis of an underlying ductal adenocarcinoma of the breast.
Paget's disease of the nipple should not be confused with the metabolic bone disease that is also called Paget's disease. In Paget's disease of the nipple, metastatic disease is often present at the time of the diagnosis.
Paget's disease of the nipple also occurs at other sites, most often in the groin or perianal area (extramammary Paget's disease). The bladder, anus, and rectum are the most common sites. Extramammary Paget's disease is a rare intraepithelial adenocarcinoma of apocrine gland–bearing sites.
The redness, oozing, and crusting closely resemble dermatitis; but physicians should suspect carcinoma because the lesion is sharply marginated, unilateral, and unresponsive to topical therapy. Biopsy shows typical histologic changes. Because this tumor is associated with underlying cancer, systemic evaluation is required.
Treatment involves surgical removal of discovered tumors, including possible mastectomy for disease involving the nipple. Treatment may also involve ablation of overlying cutaneous involvement, either surgically or by CO2 laser ablation.
Last full review/revision October 2008 by Gregory L. Wells, MD