PAGET DISEASE OF
THE NIPPLE
Paget disease of the breast is rare, comprising between 1% and 2% of breast carcinomas. It is a malignant process that involves the nipple and areola. Rarely, it may also involve the skin of the vulva. This lesion has an innocent appearance that looks like eczema or dermatitis of the nipple. The clinical picture is produced by an infiltrating ductal carcinoma that invades the epidermis. Paget disease has an excellent prognosis.
Paget carcinoma is characterized by
invasion of the nipple or areola and the mouths of the larger ducts by large
malignant cells resembling those seen in transitional cell carcinoma of the
mucous membranes else-where in the body. It is thought to arise in the
dermoepidermal junction from multipotent cells that can differentiate into either
glandular or squamous cells. The average age at diagnosis is 62 for women and 69 for men. The duration of symptoms, which is
approximately 3 years, and the symptoms, referable to the nipple, are
characteristic clinical features of the disease. Paget disease is almost always
associated with infiltrating or intraductal carcinoma in deeper parts of the
breast (95% of cases). In most of the cases, involvement of the nipple precedes
a definite tumor of the breast, but in a few instances the lump in the breast
may be noted first. The disease is bilateral in less than 5% of the cases.
Mammography is usually used to detect deeper lesions and lesions in the
contralateral breast. In addition, a touch smear obtained by softening the
crust with saline and gently scraping the surface often demonstrate the
characteristic Paget cells.
The involved nipple has either a red
granular appearance or is crusted and eczematous. After an interval of a few
months, both the eczematous and the granular types undergo ulceration. Serum or
blood oozes from the denuded region. A small amount of blood may be obtained on
manipulation. In early stages, the zone immediately surrounding the nipple is
indurated, whereas in later stages both the central zone and the periphery may
be involved by a hard mass. Palpable axillary nodes are found in about 50% of
the cases.
Grossly, besides the changes in the
nipple, the larger ducts are dilated and filled with blood or inspissated
secretion. Microscopically, large cells with deep staining or vesicular nuclei
and pale-staining cytoplasm are found in the epidermis of the nipple. Mitotic
figures are frequent. Dermal infiltrates of large neoplastic cells (Paget cells)
are defining features of this condition. These cells have abundant clear
cytoplasm with mucin and irregular prominent nucleoli. Most often, these cells
arise from infiltrating ductal carcinoma. In cases where the cells in the nipple
have infiltrated beyond the basement membrane, they invade both the larger ducts and the breast tissue.
Therapy is focused on treatment of
the underlying malignancy and is most commonly surgical. When limited to the
nipple, breast conservation may be possible. Adjunctive hormonal or
chemotherapy is often recommended based on cell type and stage. Radiation
therapy is a common adjuvant therapy following breast-conserving surgery.
The differential diagnosis from
benign lesions of the nipple, such as keratosis and ulcers, depends largely on
the discovery of a mass in the underlying tissue on
palpation. Although biopsy of the nipple should be avoided whenever possible, a
study of the tissue becomes imperative in certain cases, for example, when the
skin lesion does not heal within a matter of days under hygienic measures or on
application of petrolatum. Even if the gland does not appear to be involved, it
is important that the biopsy specimens obtained from such patients should
contain not only skin b t also a representative portion of the mammary ducts.
