Meningioma
All the information on the causes, symptoms, and most effective treatments of benign cysts in the meninges.
Symptoms and Causes
Meningioma is a type of tumor that develops in the membranes surrounding the brain and spinal cord. Most are benign, slow-growing tumors that can cause brain damage due to pressure on tissues, nerves, and blood vessels.
There are different types of meningiomas depending on their severity:
- Benign meningioma (Grade I): the most common type. It grows slowly and is non-cancerous.
- Calcified meningioma: a type of benign cyst containing calcium deposits, indicating very slow growth or halted progression.
- Atypical meningioma (Grade II): benign but fast-growing, with a high likelihood of recurrence even after surgical removal.
- Anaplastic meningioma (Grade III): lacks cellular differentiation, making it more aggressive and considered malignant.
Although meningiomas can occur anywhere within the meninges, they are most commonly found on the cranial vault—the convex outer surface of the skull—or at the skull base.
The prognosis of meningioma is variable and depends on tumor progression. Its growth is usually slow, so the initial treatment often involves regular monitoring to prevent complications.
Symptoms
Meningiomas can remain asymptomatic for long periods, sometimes years, due to their slow growth. When symptoms do appear, they vary depending on the tumor’s location:
- Cerebral convexity:
- Seizures
- Cognitive deficits: language difficulties, decision-making problems, memory loss
- Intracranial hypertension
- Skull base:
- Visual changes: blurred vision or double vision (diplopia)
- Vision loss
- Difficulty moving eye muscles
- Exophthalmos: protrusion of the eyeball
- Gait disturbance
- Limb movement incoordination
- Weakness in arms and legs
- Facial paralysis
- Vertigo
- Tinnitus: ringing in the ears
- Hearing loss
- Dysphagia: difficulty swallowing
- Dysarthria: difficulty articulating words
- Nystagmus: involuntary eye movement
- Facial numbness or loss of tactile sensitivity
- Seizures
- Headaches
- Lhermitte’s sign: sensation of an electric shock running down the spine when bending the neck
- Other locations:
- Anosmia: loss of smell
- Hydrocephalus: fluid accumulation in the brain
Causes
Meningioma forms when meningeal cells mutate and begin uncontrolled growth, though the precise triggers for this process remain unknown.
Risk Factors
Factors that increase the risk of developing a meningioma include:
- Childhood exposure to radiation
- Head radiotherapy treatments
- Female sex: these cysts are more common in women, suggesting a hormonal influence in their development
- Advanced age: due to their slow growth, meningiomas are usually detected in older adults
- Neurofibromatosis type 2: an inherited genetic disorder promoting benign tumor formation in the brain and spinal cord
- Family history
- Obesity: meningiomas appear more frequently in overweight individuals, although the reasons are not fully understood
Complications
Major complications of untreated or excessively growing meningiomas include:
- Personality changes
- Concentration problems
- Severe disability
Prevention
Meningiomas cannot be prevented.
Which Specialist Treats Meningioma?
Meningioma is diagnosed in neurology consultations and treated in the neurosurgery specialty.
Diagnosis
Meningioma diagnosis is confirmed through the following tests:
- Computed Tomography (CT): Iodine-based contrast is administered to enhance tumor visibility, which appears brighter due to its density.
- Magnetic Resonance Imaging (MRI): Provides detailed images of brain structures and the cyst, allowing precise localization and size assessment.
- Biopsy: Performed if malignancy is suspected. A tissue sample is obtained through a small cranial opening for histological evaluation.
Treatment
Meningioma management depends on tumor location, growth rate, characteristics, and patient age and health status. Common approaches include:
- Periodic monitoring: For asymptomatic, slow-growing tumors, no immediate treatment is applied. Regular follow-ups are scheduled to track progression and prevent complications.
- Surgical resection: The tumor is removed entirely if possible. However, proximity to delicate structures often limits resection to partial removal.
- Radiotherapy: Used as an alternative or adjunct to surgery, radiation reduces the risk of recurrence or shrinks the tumor.
- Chemotherapy: Reserved for Grade III meningiomas.
