Is Meningioma Dangerous? Differences Between Benign and Malignant Meningiomas

Meningioma is the term used for tumors that develop from cells associated with the membranes called the meninges, which surround the brain and spinal cord. One of the most common questions among patients diagnosed with meningioma is, “Is meningioma dangerous?” A significant proportion of meningiomas are slow-growing and low-grade tumors. However, the fact that a tumor is benign does not mean that it is insignificant or risk-free in every case.

The risk posed by a meningioma may vary depending on the size of the tumor, its location in the brain, its growth rate, its relationship with surrounding nerves and blood vessels, and its pathological grade. Meningiomas that develop in critical areas of the brain may cause significant neurological problems even when they are small.

Prof. Dr. Ömür Günaldı states that when evaluating meningiomas, rather than focusing solely on whether the tumor is benign or malignant, it is important to consider the tumor’s location, size, growth tendency, and neurological effects on the patient together.

Is Meningioma Dangerous?

The majority of meningiomas are low-grade and grow slowly. Some small meningiomas may not cause any symptoms for many years. They may even be detected incidentally during a brain MRI performed for another reason.

In these patients, when the characteristics of the tumor are suitable, regular MRI monitoring at specific intervals may be preferred instead of immediate surgery.

However, some meningiomas may grow and put pressure on brain tissue, nerves, or blood vessels. In such cases, symptoms such as headaches, seizures, vision problems, weakness in the arms or legs, balance problems, and speech difficulties may occur.

Therefore, whether a meningioma is dangerous should be evaluated individually for each patient.

Is Meningioma Benign?

A significant proportion of meningiomas are low-grade tumors. In the current classification, meningiomas are classified as WHO Grade 1, Grade 2, and Grade 3 according to their biological and pathological characteristics.

WHO Grade 1 meningiomas generally tend to grow more slowly. Their potential for recurrence after treatment is lower compared with higher-grade meningiomas.

However, the term “benign” should not create a false sense of security in patients. Because the brain is located within a confined space, even a benign tumor may put pressure on important structures as it grows.

Prof. Dr. Ömür Günaldı therefore emphasizes that the anatomical location of a meningioma is as clinically important as its biological characteristics.

Can a Benign Meningioma Be Dangerous?

Yes. A low-grade meningioma may cause serious problems in some cases.

For example, a meningioma located near the optic nerve may affect vision as it grows. Tumors located near areas of the brain responsible for motor functions may cause weakness in the arms or legs.

Some meningiomas located at the skull base may also be closely associated with important nerves and blood vessels.

Therefore, when evaluating the risk of a meningioma, the pathology result alone is not considered. The anatomical location of the tumor and the pressure it places on surrounding structures are also evaluated.

What Is a Malignant Meningioma?

A smaller proportion of meningiomas may be high-grade and show more aggressive biological characteristics. WHO Grade 3 meningiomas, in particular, may behave differently from low-grade tumors in terms of faster growth and recurrence after treatment.

WHO Grade 2 meningiomas may have a higher potential for recurrence or progression compared with Grade 1 tumors.

For this reason, dividing meningiomas into only two groups as “benign” and “malignant” is no longer sufficient to explain all aspects of the disease.

Prof. Dr. Ömür Günaldı states that the WHO grade in the pathology report and, when necessary, molecular characteristics are taken into consideration when planning follow-up after treatment.

Differences Between Benign and Malignant Meningiomas

There may be several fundamental differences between low-grade meningiomas described as benign and meningiomas with more aggressive characteristics.

Growth Rate: Low-grade meningiomas generally grow more slowly. Some may show very little change for years.

Higher-grade meningiomas may tend to grow more rapidly.

Risk of Recurrence: The risk of recurrence is generally lower in low-grade meningiomas that can be completely removed.

In higher-grade meningiomas, the likelihood of the tumor growing again after treatment may be higher.

Pathological Characteristics: The microscopic characteristics of tumor cells, their division activity, and certain molecular changes may be used to determine the grade of a meningioma.

Follow-Up Process: While follow-up intervals for low-grade tumors are arranged according to the individual patient, higher-grade meningiomas may require more frequent imaging follow-up.

Need for Additional Treatment: Surgery may be sufficient for some low-grade meningiomas, while small tumors may only require monitoring. In higher-grade meningiomas, additional treatments such as radiotherapy may be considered after surgery.

When Does a Meningioma Become Dangerous?

The risk posed by a meningioma does not depend solely on the grade of the tumor. Its location and size are also important.

• Rapid tumor growth
• Development of epileptic seizures
• Vision loss or double vision
• Weakness in the arms or legs
• Balance and walking problems
• Speech disorders
• Pressure on important blood vessels or nerves
• Significant compression or edema in brain tissue
• Regrowth of the tumor after treatment

The presence of any of these findings does not directly mean that the tumor is malignant. A low-grade meningioma may also cause serious symptoms because of its location.

Prof. Dr. Ömür Günaldı states that neurological symptoms and imaging findings should be evaluated together when making treatment decisions.

What Are the Symptoms of Meningioma?

Meningioma symptoms may vary depending on the location of the tumor. Small tumors may cause no symptoms at all.

• Headache
• Epileptic seizures
• Blurred vision
• Double vision
• Hearing problems
• Numbness in the arms or legs
• Loss of strength
• Balance problems
• Difficulty walking
• Speech problems
• Changes in memory or concentration

It should be remembered that these symptoms are not specific to meningioma. Similar complaints may occur in many different conditions.

How Can You Tell Whether a Meningioma Is Benign or Malignant?

Imaging methods such as MRI and computed tomography can provide important information about the location and size of the tumor and its relationship with surrounding tissues.

However, determining the exact grade of a meningioma is primarily based on pathological evaluation of the tumor tissue.

Tumor tissue obtained during surgery is examined under a microscope. Molecular examinations may also be performed when necessary.

Prof. Dr. Ömür Günaldı states that evaluating the preoperative radiological findings together with the postoperative pathology results helps in planning subsequent treatment.

Is a Benign Meningioma Surgically Removed?

Not every low-grade meningioma requires surgery. Some small tumors that do not cause symptoms and do not show growth during follow-up may be monitored.

During follow-up, MRI scans are performed at certain intervals to evaluate changes in the size of the tumor.

Surgical treatment may be considered if the tumor grows, causes neurological symptoms, or puts pressure on critical structures.

Is Meningioma Surgery Dangerous?

The level of risk associated with meningioma surgery varies from patient to patient. The location and size of the tumor and its relationship with important blood vessels and nerves may affect the complexity of surgery.

Some meningiomas located close to the surface of the brain may be more surgically accessible, while tumors located at the skull base or around major blood vessels may make surgery more complex.

The goal of surgery is to safely remove as much of the tumor as possible while preserving neurological functions to the greatest extent possible.

Prof. Dr. Ömür Günaldı emphasizes that while complete tumor removal may be the goal, patient safety and preservation of neurological functions are fundamental considerations in surgical planning.

Can Meningioma Recur?

Meningioma may recur after treatment. The likelihood of recurrence may be influenced by factors such as the WHO grade of the tumor, the extent to which it was surgically removed, its anatomical location, and its biological characteristics.

In general, the risk of recurrence is higher in high-grade meningiomas. However, the possibility of recurrence is not completely eliminated in low-grade meningiomas.

Therefore, regular medical check-ups and MRI examinations at intervals considered necessary are important after surgery.

How Is Meningioma Treated?

Three main approaches are used in meningioma treatment: monitoring, surgery, and radiotherapy.

Some small meningiomas that do not cause symptoms may be monitored with regular MRI examinations.

Surgical treatment may be considered for meningiomas that are growing, causing symptoms, or putting pressure on important surrounding structures.

Radiotherapy may be used for some tumors that cannot be completely removed, recur, or carry a higher risk because of their pathological characteristics. Stereotactic radiosurgery may also be considered for some small meningiomas with suitable characteristics.

Prof. Dr. Ömür Günaldı states that the choice of treatment should be determined by evaluating the tumor’s grade, location, size, and the patient’s overall condition together.