Prognosis for vulvar Paget's disease called excellent.(extramammary Paget's disease )

BETHESDA, MD. -- Extramammary Paget's disease is most often found in the vulvar area and usually has an excellent prognosis, Peter J. Lynch, M.D., said at a conference on vulvovaginal diseases.

The vulva is the site of about 65% of extramammary Paget's disease (EMPD), which accounts for about 1% of all vulvar malignancies, said Dr. Lynch, emeritus professor and training program director, department of dermatology, University of California, Davis. EMPD is a disease of the elderly, affecting women 55-90 years old, with a mean age of 65. It occurs primarily among whites, although it has been reported increasingly among Asians over the past 4-5 years.

The lesions are primarily found along the "milk line," where the sites of involvement are anywhere apocrine glands are found, including the axillae, breast, and perianal area.

Typically, extramammary Paget's lesions are similar in appearance, with an erythematous plaque that is sharply marginated. The surface of these lesions is often moist and/or crusted, but patients also may have frank erosions, he said. Whiteness in the vulvar area can be due to the absence of melanocytes, or caused by what happens when keratin gets waterlogged, since keratin is highly hydrophilic. Any disease with a buildup of keratin occurring in a wet area will have whitening in some areas, he explained.

While it may be suspected, the correct diagnosis is rarely made clinically, and generally requires a biopsy. Failure to respond to treatments, such as topical steroids and "anticandidals," should prompt a biopsy. Diseases that may look like this condition but are less common include lichen planus and lichen sclerosis, Dr. Lynch said at the conference, sponsored by the American Society for Colposcopy and Cervical Pathology.

Histology, which is distinctive, but not pathognomonic, is characterized by clusters of pale staining cells in the epidermis, with variable extension into the hair follicles and sweat glands. However, the degree ...