Meningiomas are the most common benign brain tumor and arise from the brain coverings.
The optimal treatment for the great majority of symptomatic meningiomas is maximal safe surgical removal. Fortunately, most meningiomas can be removed through a keyhole surgical route that minimizes collateral damage to surrounding brain, blood vessels and nerves.
At the Pacific Neuroscience Institute, we have one of the world’s largest experiences treating all types of meningiomas with keyhole and endoscopic approaches as well as treating residual and recurrent meningiomas that have had prior treatments, as well as treating aggressive meningioma subtypes (atypical and anaplastic). By incorporating cutting edge technology and instrumentation with proven surgical experience, we make meningioma surgery safer, less invasive and more effective.
For meningiomas that cannot be completely removed, stereotactic radiotherapy (SRT) or Stereotactic Radiosurgery (SRS), may be needed to halt further tumor growth. Our team of radiation oncologists has extensive experience in treating such residual meningiomas with precision radiotherapy. Additionally, we routinely collect meningioma tissue at surgery for tumor genetic profiling, to help guide novel targeted therapies and clinical trial options, which can be critical for controlling aggressive meningioma subtypes.
Keyhole Brain Tumor
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What is a meningioma brain tumor?
Meningiomas are the most common benign brain tumor although up to 10% can exhibit more aggressive growth patterns. Meningiomas are classified by the World Health Organization into 3 grades based on their growth pattern and histology:
• Grade I (typical – 90%)
• Grade II (atypical – 6-9%)
• Grade III (anaplastic 1-3%). These tumors arise from arachnoidal cap cells in the brain coverings (meninges).
How common are meningiomas?
They are more common in women than men and can occur in all ages but are typically seen in middle-aged and older adults.
What causes meningiomas?
They may arise from any meningeal surface and are typically attached to the dura (outer layer of the meninges) but can also occur in the cerebral ventricles.
Types and Location of meningioma brain tumors:
• Planum sphenoidale meningioma
Common locations include the convexity of the calvarium, frontal fossa (olfactory groove), tuberculum sella, sphenoid wing and the area around the jugular foramen in the posterior fossa.
What are the Symptoms of Meningiomas Brain Tumor?
Meningiomas may produce a variety of symptoms depending upon their location.
Meningiomas that arise in the midline from the area above and in front of the pituitary gland and sella (the tuberculum sella and planum sphenoidale), typically cause progressive visual loss from optic nerve and chiasm compression. They may also cause headache, double vision and loss of pituitary function.
Meningiomas that arise in the midline under the frontal lobe in the area called the olfactory groove typically cause headache, seizures and/or personality changes.
Meningiomas that arise over the surface of the frontal, temporal, parietal or occipital lobes may cause a variety of symptoms including headache, seizures, visual loss, double vision, weakness, fatigue, difficulty walking, confusion and personality changes.
Meningiomas that arise in the posterior fossa along the side of the cerebellum or brainstem (so-called petro-clival meningiomas) or at the skull base where the spinal cord begins, may cause difficulty walking, in-coordination, numbness, hearing loss, double vision, difficulty swallowing, urinary incontinence, headache and neck pain.
How are Meningiomas Diagnosed?
Meningiomas are best diagnosed by an MRI of the brain with gadolinium, or by a CT scan of the brain with contrast. Depending upon the location, a focused MRI of the pituitary region, temporal bones, internal auditory canals or orbits may be indicated to obtain better anatomical detail of a meningioma. Other tests may also be needed such as angiography (a CT angiogram or an MR angiogram), visual field tests, an audiogram or hormonal tests.
Symptomatic meningiomas typically require surgical removal. The surgical approach depends upon tumor location.
For many “convexity” meningiomas that are on the superficial surface of the brain, a keyhole craniotomy performed directly over the tumor is performed.
For other meningiomas that arise from the skull base and are partially covered by the brain, other keyhole routes that provide the shortest, safest corridor to the tumor are used. These minimally invasive approaches most commonly include the supraorbital (eyebrow) approach, the retromastoid approach and the endonasal endoscopic approach (via the nose).
Our Center Director, Dr. Daniel Kelly has been one of the pioneers in removing tuberculum sellae meningiomas through an endonasal endoscopic approach and comparing this route to the supraorbital eyebrow approach. The advantage of the endonasal approach over a transcranial approach is that brain retraction is not necessary and manipulation of the optic nerves and chiasm is minimized.
However, for larger tumors (over 3 or 4 cms) or those that extend far off the midline, the supraorbital eyebrow craniotomy is an excellent minimally invasive approach. With either approach, vision typically improves and pituitary hormonal function is usually preserved.
Our team of endoscopic skull base surgeons including neurosurgeons Dr. Daniel Kelly and Dr. Garni Barkhoudarian and ENT Surgeons Drs. Chester Griffiths and Kian Karimi, have one of the largest surgical experiences treating patients with all types of parasellar meningiomas involving the petroclival region, cavernous sinus, Meckel’s cave and orbit.
To learn more about meningiomas, including comprehensive care and keyhole surgery options, go to our video library.
Meningiomas cannot be completely removed by surgery in up to 20-25% of cases. With incomplete removal or if a tumor re-grows, stereotactic radiotherapy (SRT) or Stereotactic Radiosurgery (SRS), are often needed to halt further tumor growth. The tumor control rate with SRS or SRT is quite high with over 90% of patients having no further tumor growth. Complications of SRS or SRT such as visual loss or brain injury are rare.