(See also Overview of Skin Cancer.)
Paget disease of the nipple should not be confused with the metabolic bone disease that is also called Paget disease. In Paget disease of the nipple, metastatic disease is often present at the time of the diagnosis.
Paget disease of the nipple also occurs at other sites, most often in the groin or perianal area (extramammary Paget disease). Extramammary Paget disease is a rare adenocarcinoma that can either arise from apocrine glands of the skin or extend from a cancer in the bladder, anus, or rectum.
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 (eg, history and physical examination, age-appropriate cancer screening, imaging) is required.
Treatment of Paget disease of the nipple involves appropriate breast cancer treatment for discovered underlying tumors and includes wide excision of the nipple-areolar complex. If no underlying breast cancer is found, either mastectomy or nipple-areolar complex resection followed by radiation treatment may be used.
Treatment of extramammary Paget disease may also involve ablation of overlying cutaneous involvement by using topical therapies (eg, topical 5-fluorouracil, imiquimod, photodynamic therapy), radiation therapy, surgery, or CO2 laser ablation. A thorough evaluation to rule out an internal cancer should be done.