Author: Vanessa Ngan, Staff Writer, 2003.
Extramammary Paget disease of the skin is a rare intraepithelial cancer characterised by a chronic eczema-like rash around the axillae or anogenital regions of males and females. Under the microscope, extramammary Paget disease looks very similar to the more common mammary Paget disease that occurs on the breast.
Extramammary Paget disease most commonly occurs in the vulva of women aged between 50–60 years. It can also affect the axilla and the anogenital area in males of similar age. It has been observed that it is more common in Asians than in Europeans and very rare in African-Americans.
Extramammary Paget disease of the skin has been classified into several subtypes.
Sometimes the extramammary Paget disease has been present for 10–15 years before evidence of underlying cancer or metastases appears.
The most common symptom of extramammary Paget disease of the skin is mild to intense itching of a lesion found around the groin, genitalia, perineum or perianal area. Pain and bleeding may occur from scratching lesions that have been around for a long time. Thickened plaques may form that can become red, scaly and crusty.
In women, the most common area involved is the vulva. First symptoms are usually itching and burning of one or more persistent plaques. These may spread to the labia, mons pubis, vagina and thighs. Perianal lesions may extend up into the anal canal.
In men, the most common area is the scrotum followed by perianal disease, penis, and groin.
The axilla is a rare site for extramammary Paget disease of the skin.
The location of extramammary Paget disease is useful in predicting the risk of associated cancer. For example, 25–35% of extramammary Paget disease arising near the anus is associated with an underlying colorectal cancer.
Skin biopsy of the lesion is performed to get an accurate diagnosis of extramammary Paget disease as there are several other genital skin diseases that may appear similar. Under microscopy, the presence of Paget cells along with other histological findings confirms the diagnosis. Special stains may be necessary to distinguish Paget disease from early melanoma (melanoma in situ). See extramammary Paget disease pathology.
Further tests may include:
Wide local excision, vulvectomy, or if available, margin-controlled surgical excision (Mohs micrographic surgery) is the standard treatment for extramammary Paget disease. Paraffin sections are preferred over frozen sections. The margin is sometimes difficult to define when lesions are spread sporadically throughout the anogenital region. Reconstruction may require skin grafting or flap repair.
Recurrence is common (30–50%), so patients should be re-examined every three months after surgery for the next two years, after which annual follow-ups are recommended. Recurrence generally leads to further surgery.
Non-surgical treatments for recurrent disease may include:
Paget disease has low mortality. Prognosis is worse if there is underlying cancer, the patient is over 70 years of age, and the Paget disease is located in the anal region.
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