Tumefactive multiple sclerosis (MS) is a rare type of MS that causes a tumor-like lesion in your brain. This lesion can press on nearby parts of your brain, leading to many symptoms.

Multiple sclerosis (MS) is a neurodegenerative disease involving the breakdown of myelin, the insulating layer that covers your nerves. Tumefactive MS is a rare form of the disease that causes symptoms that mimic those of a brain tumor.

Tumefactive MS causes a tumor-like lesion in your brain and can lead to different symptoms depending on where the lesion forms. Paralysis on one side of your body is one of the most common initial symptoms.

The outlook for tumefactive MS varies significantly, but getting a diagnosis early and starting treatment as soon as possible is usually associated with a better outlook.

Read on to learn more about this rare form of MS.

‘Tumefactive’ meaning

The word “tumefactive” means “swelling” or “tumor-like.” In the case of tumefactive MS, it refers to the development of a tumor-like lesion in your brain.

Tumefactive MS can cause different symptoms depending on where in your brain the tumor-like lesion develops. The first symptom in about two-thirds of people is paralysis on one side of the body.

This disease most often affects the frontal and temporal lobes of the brain. Potential symptoms include:

Swelling in your brain can cause symptoms such as:

Tumefactive MS often follows a relapsing-remitting course in which symptoms flare up periodically.

The cause of tumefactive MS is still unknown. People with tumefactive MS develop a tumor-like mass in their brain that’s larger than 2 centimeters (0.8 inches) across.

MS is thought to develop when your immune system attacks myelin, the fatty layer of tissue that insulates your nerves. The destruction of myelin slows down the conduction of electrical signals through your nerves.

Tumefactive MS is most often diagnosed in people who are 20–30 years old, and about three-quarters of people with MS are female. In one study examining data from slightly more than 100 people with tumefactive MS in Italy, 10% of people had another autoimmune disease.

Research suggests that certain genes may make you more likely to develop MS and that environmental factors may further contribute to that likelihood.

MS is a progressive condition. If left untreated, it often progresses and causes severe disability or life threatening complications.

The mass that forms in your brain in tumefactive MS can put pressure on healthy brain tissue and lead to various complications depending on which part of your brain it affects. In some cases, you may develop bleeding in your brain.

A doctor will start the diagnostic process by asking you about your symptoms and reviewing your personal and family medical history. Tumefactive MS can cause symptoms similar to those of a brain tumor.

MRI is the best imaging technique to distinguish tumefactive MS from a brain tumor.

Other tests you may receive include:

It’s essential to consult a doctor as soon as possible if you develop symptoms of MS or another serious neurological condition, such as:

  • paralysis
  • changes in your ability to think
  • difficulty with walking or movement

Once you receive a diagnosis, it’s important to go to all your regular follow-up appointments to track the progression of the disease.

Tumefactive MS doesn’t have a cure, but treatment can help reduce inflammation and symptoms.

High dose corticosteroids are the first-line treatment. About 86% of people experience improvement with this treatment. Plasmapheresis is the second-line therapy for people who don’t respond to corticosteroids. It involves removing plasma from your blood and returning the blood to your body.

If these treatments aren’t effective, your doctor may prescribe other medications, such as:

  • the biological medication rituximab
  • the chemotherapy drug cyclophosphamide
  • intravenous immunoglobulin
  • disease-modifying agents such as interferon-beta and glatiramer acetate

Researchers don’t yet know why tumefactive MS develops or how to prevent it. Maintaining healthy lifestyle habits may reduce your chances of developing MS in general, although it’s not clear by how much. These habits may include:

Learn more about preventing MS.

The outlook for tumefactive MS varies significantly from person to person. About one-third of people don’t experience any further attacks on their nerves. Of those who do have further attacks, about two-thirds experience a relapsing-remitting course of the disease.

Early diagnosis and treatment are generally linked to better outcomes.

Here are some frequently asked questions people have about tumefactive MS.

How rare is tumefactive MS?

Tumefactive MS affects 1–3 of every 1,000 people with MS, and MS is estimated to affect 1 in 2,800 people.

Is tumefactive MS hereditary?

Healthcare professionals think genes passed through families may contribute to the development of MS, but they don’t yet fully understand the genetics of the disease.

What size lesion is considered tumefactive multiple sclerosis?

Tumefactive MS usually causes a lesion that is larger than 2 centimeters across.

What types of tumors are associated with multiple sclerosis?

Tumefactive MS causes a tumor-like lesion in your brain. This lesion can press on areas of your brain and cause many different symptoms.

Some research suggests that people with MS may be at an increased risk of brain cancer. However, the increased rates might be attributed to more frequent brain imaging in people with MS than in the larger population.

Receiving an earlier diagnosis of tumefactive MS is generally associated with a better outlook. The disease doesn’t yet have a cure, but medical treatment can help you manage the disease and its symptoms.