Meningioma

Meningiomas start in the meninges, the layers of tissue that cover and protect the brain and spinal cord. They usually grow slowly and may go undetected for years. Sometimes they’re found by accident during an MRI or CT scan. Meningioma is the most common primary brain tumor, making up about 30 percent of all brain tumors.

Types & Stages

Meningiomas are named for where they grow, including the brain surface, skull base, ventricles or areas near the optic nerves, pituitary gland or cranial nerves. Some types are harder to remove because of their location.

They are also graded by how abnormal the cells look:

• Grade I (benign): Most common and usually slow-growing
• Grade II (atypical): More likely to invade nearby tissue and return after treatment
• Grade III (malignant): Rare, faster-growing, and most likely to recur or spread

Signs & Symptoms

Symptoms often develop gradually and depend on the tumor’s size and location. They may include:

• Headaches
• Seizures
• Blurred vision
• Weakness in the arms or legs
• Numbness
• Balance problems
• Hearing loss
• Memory loss

Diagnosis

Doctors may use:

• Neurological exam to check vision, hearing, balance, strength and reflexes
• Imaging tests such as MRI or CT scans to find the tumor and assess its size and location

Treatment

Treatment depends on the tumor’s size, location, growth rate and symptoms.

• Monitoring: Small, slow-growing tumors without symptoms may only need regular scans
   
• Surgery: Often the main treatment, though complete removal isn’t always possible
   
• Radiation therapy: Used when the tumor can’t be fully removed, returns or is more aggressive
  • Radiation options may include stereotactic radiosurgery, external beam radiation, IMRT or proton beam therapy.

Causes & Risk Factors

The exact cause is unknown, but risk factors include:

• Older age
• Female sex
• Prior radiation exposure to the head or neck
• Inherited conditions such as neurofibromatosis type 2

Screening

Screening with MRI or CT may be recommended for people at higher risk.