A 62-year-old woman presents with a 6-month history of an eczematous, scaly, rash near her nipple. It is mildly pruritic. On physical examination, the nipple and the areola are involved (Figure 96-1). Also, a hard mass is present in the lateral lower quadrant of the same breast. A 4-mm punch biopsy of the affected area including the nipple demonstrates Paget disease. The mammogram is suspicious for breast cancer at the site of the mass, and the patient is referred to a breast surgeon.
Paget disease of the breast of a 62-year-old woman that presented as a persistent eczematous lesion. (Reproduced with permission from Richard P. Usatine, MD.)
Paget disease of the breast is a low-grade malignancy of the breast that is often associated with other malignancies. It is an important consideration when working up a chronic persistent abnormality of the nipple.
Paget's disease, mammary Paget disease.
The incidence of Paget disease of the breast is approximately 0.4% in women in the United States, according to National Cancer Institute Surveillance, Epidemiology, and End Results (SEER) data.1 Paget disease, like all breast cancers, is rare in men.
The peak incidence is between 50 and 60 years of age.2
It is associated with underlying in situ and/or invasive breast cancer 85% to 88% of the time.3
Some epidemiologic data suggest that the incidence of Paget disease of the breast is decreasing over time.3
ETIOLOGY AND PATHOPHYSIOLOGY
Most patients delay presentation, assuming the abnormality is a benign condition of some sort. The median duration of signs and symptoms prior to diagnosis is 6 to 8 months.2
Presenting symptoms are sometimes limited to persistent pain, burning, and/or pruritus of the nipple (Figures 96-1 and 96-2).
A palpable breast mass is present in 50% of cases, but is often located more than 2 cm from the nipple–areolar complex.4
Twenty percent of cases will have a mammographic abnormality without a palpable mass, and 25% of cases will have neither a mass nor abnormal mammogram, but will have an occult ductal carcinoma.
In less than 5% of cases, Paget disease of the breast is an isolated finding.4
There are two theories regarding the pathogenesis of Paget disease of the breast, the choice of which affects treatment choices.
The more widely accepted epidermotropic theory proposes that the Paget cells arise from an underlying mammary adenocarcinoma that migrates through the ductal system of the breast to the skin of the nipple. It is supported by the fact that Paget disease is usually associated with an underlying ductal carcinoma, and both Paget cells and mammary ductal cells usually express similar immunochemical ...