Dermatofibrosarcoma Protuberans (DFSP)

What is dermatofibrosarcoma protuberans (DFSP)?

Dermatofibrosarcoma protuberans is a rare skin cancer that begins in your dermis, your skin’s middle layer. It’s pronounced “dur-MAT-toe-fy-bra-sar-CO-ma” “pro-TOO-bur-anz.” Your healthcare provider might call it DFSP.

This slow-growing cancer rarely spreads. Still, you need treatment to remove the tumor and prevent cancer from coming back (recurrence) or spreading (metastatic cancer). With proper treatment, DFSP has a high survival rate.

Is dermatofibrosarcoma protuberans (DFSP) benign?

No. DFSP is a malignant (cancerous) soft tissue tumor and a type of skin cancer.

DFSP is a sarcoma (soft tissue tumor), cancer that develops in muscle, fat and skin. These tumors can also affect bones.

Can DFSP metastasize (spread)?

Cancer that spreads outside the original tumor is metastatic cancer. Approximately 1 in 20 people with DFSP experience cancer spread.

Metastatic DFSP is most likely to occur if you don’t get treatment or the cancer goes deep into fat and muscle.

For unknown reasons, DFSP can be more aggressive when it develops during pregnancy.

A small percentage of people with DFSP have an aggressive type called fibrosarcomatous dermatofibrosarcoma protuberans (DFSP-FS). These tumors are more likely to spread and come back after surgical removal.

How common is dermatofibrosarcoma protuberans (DFSP)?

DFSP is a rare cancer that affects approximately 4 out of 1 million people worldwide each year. They account for 1% to 6% of all soft tissue sarcomas.

The cancer typically affects adults ages 20 to 50, but children also get this skin cancer. Some infants have DFSP at birth. DFSP appears to affect people who are Black more often than people of other ethnicities.

What are the types of DFSP?

Pathologists (doctors who examine bodies and body tissues) examine cells under a microscope to determine the type of DFSP. Types include:

• Bednar tumors (pigmented DFSP) contain cells that have a lot of melanin, the substance that gives skin its color. Bednar tumors may have a mix of colors, including red, brown, blue and purple. These tumors account for about 5% of DFSP diagnoses.
• Giant cell fibroblastoma consists of giant cells. This type is also known as juvenile DFSP because it mostly affects children and teens.
• Fibrosarcomatous dermatofibrosarcoma protuberans (DFSP-FS) is a more aggressive cancerous soft tissue sarcoma.
• Myxoid DFSPs are made of an abnormal type of connective tissue called myxoid stroma. This type of DFSP is rare.

What causes DFSP?

As many as 9 in 10 people who develop DFSP have a gene change (mutation) that causes the condition. This gene change occurs in cells after you’re born. You don’t inherit a gene mutation from a parent that causes DFSP.

What are risk factors for DFSP?

In addition to racial factors, a skin injury or scars may increase your risk of DFSP. Causes of skin injuries include:

• Burns.
• Radiation therapy.
• Surgical incisions.
• Tattoos.

What are the signs of DFSP?

Early symptoms of DFSP are easy to dismiss or not notice. The tumors typically appear on your chest, back, shoulders, abdomen or buttocks. Tumors can also form on your arms, legs, scalp and inside of your mouth.

At first, you may notice a small patch of skin that looks like a bruise. The spot is flat and painless. It may feel rough and look discolored.

In infants and children, DFSP can look like a birthmark. These spots are usually about 1/2 inch to 2 inches (1 centimeter to 5 centimeters) across.

DFSP symptoms become more noticeable as the cancer grows. The growing tumor pushes into the top layer of skin (epidermis). Firm lumps (nodules) of tissue appear on the skin (“protuberans”).

You may notice that the nodules are:

• Easy to crack open or bleed.
• Firmly attached to your skin (don’t move).
• Getting bigger and stretching your skin.
• Hard or rubbery.
• Reddish-brown to violet, blue or red.
• Tender.

What other conditions cause DFSP symptoms?

A noncancerous skin condition called cellular dermatofibroma can look like DFSP, especially during the cancer’s early stage. Cellular dermatofibromas are benign soft tissue tumors that typically appear on your legs. They may be itchy or painful. Most dermatofibromas don’t need treatment.

How is dermatofibrosarcoma protuberans (DFSP) diagnosed?

Dermatologists, medical doctors who specialize in skin cancer and skin diseases, diagnose DFSP. Your provider will perform a skin biopsy to remove part or all of the growth. Pathologists examine the tissue under a microscope to check for cancer cells.

If the skin biopsy determines you have DFSP, you may get an MRI to determine the size and depth of the tumor.

How is dermatofibrosarcoma protuberans (DFSP) treated?

Surgical removal is the treatment of choice for DFSP. Dermatologists perform Mohs surgery to remove DFSP tumors. During the procedure, your provider:

• Injects a local anesthetic into the treatment area to numb it.
• Surgically cuts out (excises) the cancerous tumor, including a small amount of surrounding healthy tissue (called the margin).
• Uses a microscope to examine the tissue edges (margin) for cancer cells.
• Removes more tissue from the tumor site, if cancer cells are seen at the margins.
• Stops removing tissue when they can’t find any more cancer cells in the margin.
• Performs reconstructive surgery.

What are nonsurgical DFSP treatments?

DFSP tumors can grow back after surgical removal. 20% to 30% or more of people experience a recurrence of DFSP within three years after wide excision, and up to 4% to 5% recur after Mohs surgery. But tumors can recur for 10 years or more.

Healthcare providers use imatinib to treat metastatic DFSP or tumors that are too large or difficult to surgically remove. Imatinib can also shrink the tumor, making surgical removal possible. Radiation treatment can be done for incompletely excised DFSP or inoperable DFSP.

What is the outlook for people with DFSP?

With proper treatment, more than 99% of people with this nonaggressive, slow-growing cancer live 10 years or longer.

What steps can I take to improve my outlook?

These steps may improve your outlook:

• Regularly perform skin self-exams to detect skin changes early.
• Get skin exams at your provider’s office every three to six months for the first three years after treatment (and then annually) or as recommended by your provider.
• Minimize sun exposure (which increases your risk for other skin cancers) by applying sunscreen, wearing sun-protective clothing and avoiding the outdoors when the sun’s ultraviolet (UV) rays are strongest.

When should I call my provider?

You should call your healthcare provider if you notice new skin changes, such as:

• Persistent bumps or growths or new skin growths.
• Changes to moles, birthmarks, scars or tattoos.
• Skin growths that bleed easily.

What should I ask my provider?

You may want to ask your healthcare provider:

• What caused the skin cancer?
• Am I at risk for other types of skin cancer?
• What’s the best treatment for me?
• Am I at risk for metastatic cancer?
• How often should I get cancer screenings?

A note from Cleveland Clinic

Many skin changes are harmless. But some changes can indicate skin cancer or another skin disease that requires treatment. You should contact your healthcare provider whenever you notice changes to your skin. Dermatofibrosarcoma protuberans (DFSP) is a rare skin cancer that’s unlikely to spread. Still, you need surgical treatment to keep the tumors from spreading. A prompt diagnosis and treatment are critical to improving your outlook.