Your pathology report for meningioma WHO grade 2

By Jason Wasserman MD PhD FRCPC
July 17, 2025

A WHO grade 2 meningioma, also known as an atypical meningioma, is a type of brain or spinal cord tumour that starts in the meninges, the protective layers surrounding the brain and spinal cord. These tumours grow more quickly and are more likely to come back (recur) after treatment than grade 1 meningiomas. However, they are less aggressive than grade 3 (malignant) meningiomas.

Grade 2 meningiomas account for about 15–20% of all meningiomas. With appropriate treatment and close follow-up, many patients with grade 2 meningiomas do very well.

Is a WHO grade 2 meningioma a type of cancer?

WHO grade 2 meningioma is not considered a malignant tumour, but it is more aggressive than a WHO grade 1 meningioma. It may grow faster, invade nearby brain tissue, and is more likely to recur after treatment. Because of this, it often requires closer monitoring, and in some cases, additional treatment such as radiation therapy after surgery.

What are the symptoms of a grade 2 meningioma?

The symptoms of a grade 2 meningioma depend on the tumor’s location, size, and how much pressure it places on the surrounding brain or spinal cord.

Common symptoms include:

  • Headaches.

  • Seizures.

  • Weakness, numbness, or difficulty moving parts of the body.

  • Vision or hearing problems.

  • Changes in personality, memory, or behaviour.

  • Back pain or leg weakness (for spinal tumours).

Some grade 2 meningiomas are found by chance during brain imaging for another reason.

What are the types of WHO grade 2 meningioma?

WHO grade 2 meningiomas are diagnosed based on specific microscopic features seen by a pathologist or because they belong to certain subtypes that are known to behave more aggressively. The sections below describe the three types of meningioma that are automatically classified as WHO grade 2, even if they don’t show other aggressive features.

Atypical meningioma

This is the most common grade 2 subtype. It is diagnosed when the tumour shows one or more of the following:

  • High mitotic activity (meaning the cells are dividing more often than usual)

  • Brain invasion (tumour cells are growing into brain tissue)

  • Or at least three of the following: high cell density, small cell size, prominent nucleoli, sheet-like growth pattern, or spontaneous cell death (necrosis)

These features suggest the tumour may behave more aggressively than a grade 1 tumour.

Chordoid meningioma

Chordoid meningiomas have a gelatinous appearance under the microscope and resemble another tumour called chordoma. They are often found in the upper part of the brain and may be associated with inflammatory cells. These tumours tend to recur more often than grade 1 tumours, even if they look otherwise bland.

Clear cell meningioma

Clear cell meningiomas contain tumour cells with a clear, glycogen-filled cytoplasm. They often grow in the spine or cerebellopontine angle (a region near the brainstem) and tend to affect younger people, including children and young adults. These tumours are more likely to come back after treatment and can spread within the brain and spinal cord.

All three subtypes are treated more cautiously because of their increased risk of recurrence.

How is a grade 2 meningioma diagnosed?

The diagnosis is made after surgical removal of the tumour. A pathologist examines the tissue under a microscope and uses specific criteria to determine if the tumour is grade 2. Imaging studies like MRI may suggest that a tumour is more aggressive, but only a microscopic examination can confirm the grade.

What is brain invasion?

Brain invasion means that tumour cells have grown past the meninges and into the nearby brain tissue. This is an important feature in the diagnosis of atypical meningioma, even if the tumour looks otherwise noncancerous. Tumours with brain invasion have a higher risk of recurrence and may require closer follow-up and additional treatment.

What is the treatment for a grade 2 meningioma?

Treatment usually starts with surgery to remove as much of the tumour as possible. However, grade 2 tumours are more likely to come back, even after complete removal, so your doctor may also recommend:

  • Radiation therapy, especially if:

    • The tumour could not be fully removed.

    • The tumour invades the brain.

    • There are signs the tumour may grow back.

Follow-up with regular MRI scans is important to monitor for recurrence.

What does margin status mean?

After surgery, the pathologist checks the margins (edges) of the removed tissue to see if any tumour is present at the cut edge of the tissue:

  • A negative margin means no tumour cells are seen at the edge—this suggests the tumour was completely removed.

  • A positive margin means tumour cells are present at the edge—this increases the risk of the tumour coming back.

Margin status helps your doctor decide whether you may need additional treatment or closer follow-up.

What is the prognosis for a grade 2 meningioma?

The prognosis for WHO grade 2 meningioma is generally good, especially when the tumour can be fully removed and followed by appropriate treatment. However, these tumours have a higher risk of recurrence than grade 1 meningiomas.

Estimated recurrence rates:

  • About 30–50% of WHO grade 2 meningiomas may grow back over time

  • Regular follow-up with MRI imaging is essential, even after successful treatment

Your prognosis will depend on factors like:

  • How much of the tumour was removed.

  • Whether brain invasion was present.

  • The tumour’s location.

  • Your age and overall health.

Questions to ask your doctor

  • Was the tumour completely removed?

  • Do I need radiation therapy?

  • How often should I have follow-up MRI scans?

  • What is the risk that the tumour will come back?

  • What symptoms should I watch for?

  • Are there any new treatments or clinical trials available?

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