A Marjolin ulcer is a rare and aggressive type of skin cancer that grows from burns, scars, or poorly healing wounds. It grows slowly, but over time it can spread to other parts of your body, including your brain, liver, lungs, or kidneys.

In the early stages, the damaged area of skin will burn, itch, and blister. Then, a new open sore filled with several hard lumps will form around the injured area. In most cases, Marjolin ulcers are flat with raised edges.

After the sore forms, you may also notice:

  • foul-smelling pus
  • severe pain
  • bleeding
  • crusting

Marjolin ulcers can repeatedly close and reopen, and they may continue to grow after the initial sore forms.

Marjolin ulcers grow from damaged skin, often in an area of skin that’s been burned. It’s estimated that about 2 percent of burn scars develop Marjolin ulcers.

They can also develop from:

Doctors don’t know why these areas of skin damage turn cancerous. However, there are two main theories:

  • The injury destroys blood vessels and lymphatic vessels that are part of your body’s immune response, making it harder for your skin to fight off cancer.
  • Long-term irritation causes skin cells to constantly repair themselves. During this renewal process, some skin cells become cancerous.

Men are three times more likely to develop a Marjolin ulcer, according to a 2011 review of existing research. Marjolin ulcers are also more common in people who are in their 50s or live in developing countries with poor access to wound care.

This 2011 review also found that Marjolin ulcers usually grow on the legs and feet. They can also appear on the neck and head.

Most Marjolin ulcers are squamous cell cancers. That means they form in squamous cells in the upper layers of your skin. However, they’re sometimes basal cell tumors, which form in deeper layers of your skin.

Marjolin ulcers grow very slowly, usually taking 30 to 35 years to turn into cancer. In some cases, they can take as many as 75 years to develop. It only takes one Marjolin ulcer to wreak havoc on the body.

If you have a sore or scar that hasn’t healed after three months, your doctor might refer you to a dermatologist after an exam of your skin. If the dermatologist thinks the sore could be cancerous, they’ll likely perform a biopsy. To do this, they’ll remove a small tissue sample from the wound and test it for cancer.

They may also remove a lymph node near the sore and test it for cancer to see if it’s spread. This is known as a sentinel lymph node biopsy.

Depending on the results of the biopsy, your doctor might also use a CT scan or MRI scan to make sure it hasn’t spread to your bones or other organs.

Treatment usually involves surgery to remove the tumor. Your surgeon can use a few different methods to do this, including:

  • Excision. This method involves cutting out the tumor as well as some of the tissue around it.
  • Mohs surgery. This surgery is done in stages. First, your surgeon will remove a layer of skin and look at it under a microscope while you wait. This process is repeated until there are no cancer cells left.

After surgery, you’ll need a skin graft to cover the area where the skin was removed.

If the cancer has spread to any nearby areas, you may also need:

After treatment, you’ll need to follow up with your doctor regularly to make sure the cancer hasn’t returned.

If you have a large open wound or severe burn, make sure you get emergency medical treatment. This can help to reduce your risk of developing a Marjolin ulcer or serious infection. Also, be sure to tell your doctor about any sores or burns that don’t seem to be healing after two to three weeks.

If you have an old burn scar that starts to develop a sore, tell your doctor as soon as possible. You may need a skin graft to prevent the area from developing a Marjolin ulcer.

Marjolin ulcers are very serious and cause death in some cases. Your outcome depends on the size of your tumor and how aggressive it is. The five-year survival rate for a Marjolin ulcer ranges from 40% to 69%. That means that 40 percent to 69 percent of people diagnosed with a Marjolin ulcer are still alive five years after being diagnosed.

In addition, Marjolin ulcers can return, even after they’ve been removed. If you’ve previously had a Marjolin ulcer, make sure you regularly follow up with your doctor and tell them about any changes you notice around the affected area.