What Is Extramammary Paget’s Disease?
Extramammary Paget’s disease (EMPD) is a rare type of slow-growing skin condition that might be associated with different types of cancer and usually causes a red, scaly, or crusty area of the skin. Sometimes, EMPD is left undiagnosed until many years after it starts to form.
EMPD is named after Sir James Paget, a famous 19th-century British physician. Several forms of cancer carry Paget’s name due to his work in the field of pathology. The term extramammary refers to the outside of the breast and helps prevent confusion with other diseases that are also named for Paget (such as Paget disease of the breast).
About 7 to 40 percent of cases of EMPD have been associated with underlying cancer. But EMPD does not always indicate another disease. Getting appropriate treatment can help improve the symptoms and get an evaluation for underlying cancer.
Extramammary Paget’s disease is of two types-
- Primary EMPD- This type of EMPD develops in the skin on its own.
- Secondary EMPD- This type of EMPD develops because of underlying cancer.
What Causes EMPD?
Healthcare providers do not precisely know the cause of primary EMPD, but they suspect it may develop from specific types of cells found in some regions of the body. These types of cells include-
- Apocrine Gland Duct Cells- These are sweat glands (a small gland that secretes sweat) in the skin related to hair follicles.
- Toker Cells- These cells are present in the skin of the nipple and valvular tissue.
- Keratinocyte Stem Cells- These are the cells that help with skin repair.
Secondary EMPD results due to underlying cancer. Rectal cancer is the most common cause of about one-third of EMPD cases. Other cancers that may be causing secondary EMPD include-
- Anal cancer.
- Uterine cancer.
- Bladder cancer.
- Prostate cancer.
- Cervical cancer.
- Ovarian cancer.
What Are the Symptoms of Extramammary Paget’s Disease?
Skin rashes account for the main symptom of EMPD that are very similar to eczema. The available research shows that approximately 65 percent of EMPD cases affect the vulva and 20 percent affect the region around the anus.
The area of the skin may appear-
- Crusty.
- Red.
- Scaly.
The rash progresses gradually and may have irregular borders. As EMPD progresses, deep sores called ulcers or nodules may develop. Other skin symptoms may include-
- Burning and irritated skin.
- Itchy skin.
- Pain or tenderness in the skin.
- Swollen skin (edema).
EMPD often occurs when many sweat glands open into the hair follicles (apocrine skin glands). It most commonly occurs on the vulva. However, it can also appear on the skin around the-
- Anus.
- Perineum.
- Penis.
- Scrotum.
In rare cases, the appearance of EMPD on the skin near other parts of the body includes-
- Armpit.
- Abdomen.
- Bellybutton.
- Ear, eyelid, face, or scalp.
- Buttocks.
- The lower part of the chest.
- Knee or thigh.
Only about ten percent of people with EMPD do not have any symptoms.
How Is Extramammary Paget’s Disease Diagnosed?
For the diagnosis of EMPD, a healthcare provider will first ask about the symptoms and then perform a physical exam. If they suspect EMPD, then a skin biopsy may be recommended. During a biopsy procedure, a small sample of the skin is taken to examine under a microscope.
Under the microscope, a pathologist will look for large abnormal cells with distinctive characteristics known as Paget cells. They will also observe how Paget cells react to different chemicals (immunohistochemistry) to identify these cells correctly.
After the healthcare provider diagnoses EMPD, they will also order a few other tests to see whether there is a possibility of underlying cancer. These tests include-
- Screening of the breast (mammogram).
- Cervical screening (Pap smear).
- Ultrasound.
- Colonoscopy (examination of colon and rectum) or proctoscopy (examining the inside of rectum and anus).
- Cystoscopy (examination of the bladder).
- Prostate exam (screening for early signs of prostate cancer).
- Retrograde pyelogram (X-ray test to look for bladder, ureters, and kidneys).
- Needle biopsy of the lymph nodes.
- Upper endoscopy.
How Is Extramammary Paget’s Disease Treated?
Healthcare providers usually treat EMPD with surgery, which includes-
- Mohs Surgery- This procedure involves the removal of the affected skin cells by the surgeon, layer by layer. This technique helps save the healthy skin in the surrounding area.
- Wide Local Excision- In this procedure, the surgeon removes the area of EMPD and some healthy tissue surrounding the affected area. They then sew together the edges of the wound.
Surgeons often need to excise a large area of skin and other tissue. For example, some people with EMPD of their vulva may require the removal of all or part of their vulva (vulvectomy).
If surgery is not possible due to poor health or other conditions, the healthcare provider may suggest other treatments, such as-
- Immunotherapy.
- Radiation therapy.
- Laser skin resurfacing.
- Photodynamic therapy.
- Topical medications used to treat cancer (cytotoxic drugs).
Any underlying cancers will also require appropriate additional treatment.
What Is the Outlook of Extramammary Paget’s Disease?
After treatment of EMPD, ongoing visits with the doctor may be required depending on the location of EMPD. It is not uncommon for EMPD to return to the same area or surrounding area even after being treated, so follow-up is essential.
It is rare for extramammary Paget’s disease to spread. But it may progress to lymph nodes or other organs. A healthcare provider is the best person to consult and have an explanation about a particular case.
Conclusion:
Any skin rash, especially on sensitive or intimate parts of the body, can be scary, embarrassing, and frustrating. Unfortunately, extramammary Paget’s disease (EMPD) often gets mistaken for some other skin conditions and may not be appropriately diagnosed for quite some time. In addition, EMPD can be more severe in the case of underlying cancer. Fortunately, most people with EMPD live their whole lives after they receive treatment. Providers generally treat EMPD with surgery. If there is underlying cancer, it will also require cancer treatments. As this condition is typical for recurring, seeing the provider for regular visits can ensure catching it early if it returns.
