MENINGIOMA

Meningioma, a type of tumor that forms on the meninges—the three protective layers covering the brain and spinal cord—is often benign but can cause significant health issues due to its location.

These tumors specifically originate from arachnoid cells within the thin, spiderweb-like membrane of the meninges.

Cancerous vs. Benign Meningiomas:

Benign Meningiomas: Most meningiomas are benign, meaning they don’t spread to other parts of the body. However, they can still grow large and press on nearby brain areas, potentially becoming life-threatening.
Malignant Meningiomas: These are cancerous, aggressive, and can invade other tissues and spread throughout the body.

Common Locations: Meningiomas are typically found near the top and outer curve of the brain or at the base of the skull. Spinal meningiomas are rare.

Growth Pattern: These tumors usually grow slowly and inward, often reaching a large size before being diagnosed.

Causes of Meningioma

The exact cause of meningiomas is still unknown, but research indicates that 40% to 80% of meningiomas have an abnormality in chromosome 22, which normally helps suppress tumor growth. These abnormalities usually occur spontaneously but can also be part of certain genetic conditions.

Types of Meningiomas

Meningiomas are categorized by their grade and location:

By Grade:

Grade I (Typical):
- Benign and slow-growing.
- Represent about 80% of cases.
Grade II (Atypical):
- Noncancerous but grows more quickly and can be harder to treat.
- Represent about 17% of cases.
Grade III (Anaplastic):
- Malignant and aggressive.
- Represent about 1.7% of cases.

By Location:

Convexity Meningiomas:
- Grow on the brain’s surface, potentially exerting pressure.
Intraventricular Meningiomas:
- Develop within the brain’s ventricles, which carry cerebrospinal fluid (CSF).
Olfactory Groove Meningiomas:
- Located between the brain and nose, near the olfactory nerve.
Sphenoid Wing Meningiomas:
- Form along a ridge of bone behind the eyes.

There are also 15 variations based on cell type, as observed under a microscope.

Is Meningioma Considered Cancer?

While most meningiomas are benign, they can sometimes be malignant. Even benign tumors can cause serious issues if they grow large enough to press on critical brain structures.

Prevalence of Meningioma

Meningioma accounts for about 30% of all primary brain tumors. It is more commonly diagnosed in adults, particularly in individuals aged 40 to 70. Women are affected more often than men, with a ratio of approximately 2:1. Meningiomas are relatively common, diagnosed in about 97 out of every 100,000 people annually. This translates to over 170,000 new cases each year in the United States, making meningiomas the most common type of brain tumor.

Symptoms of Meningioma

Meningiomas grow slowly, often not causing noticeable symptoms until they become large enough to impact surrounding brain structures. Symptoms can vary depending on the tumor’s location:

Location-Specific Symptoms:

Olfactory Groove Meningiomas:
- Partial or complete loss of smell (anosmia).
Posterior Frontal Midline Meningiomas:
- Paralysis of the legs and lower body (paraplegia).
Sphenoid Wing Meningiomas:
- Cavernous sinus syndrome.
- Bulging of one or both eyes (proptosis).

Common Symptoms of Brain Meningiomas:

Headaches
Dizziness
Nausea and vomiting
Vision changes (double vision, blurriness, loss of vision)
Hearing loss
Seizures
Behavioral or personality changes
Memory problems
Overactive reflexes (hyperreflexia)
Muscle weakness
Paralysis

Common Symptoms of Spinal Meningiomas:

Pain at the tumor site
Radiculopathy (nerve pain radiating from the spine)
Neurological issues (weakness, poor muscle tone, decreased reflexes)

If you experience any of these symptoms, it is crucial to contact a healthcare provider promptly.

Risk Factors for Meningioma

Several factors can increase the likelihood of developing meningioma:

Age:

Meningioma is most prevalent in adults aged 65 and older.
Risk increases with advancing age.

Sex:

Individuals assigned female at birth (AFAB) are approximately twice as likely as those assigned male at birth (AMAB) to develop noncancerous meningiomas.
Hormonal factors, such as exposure to female sex hormones, may contribute to this difference.
Use of hormone replacement therapy, birth control pills, and a history of breast cancer may also elevate risk.

Radiation Exposure:

Previous exposure to radiation on the head increases the risk of developing meningiomas.

Race/Ethnicity:

In the United States, Black individuals have a higher incidence of meningiomas compared to other ethnic groups.

Genetic Factors:

Certain genetic conditions or a family history of meningiomas can elevate risk:
- Neurofibromatosis Type 2: Associated with an increased risk of cancerous meningiomas.
- Von Hippel-Lindau disease
- Multiple endocrine neoplasia type 1
- Li-Fraumeni syndrome
- Cowden syndrome

Diagnosis of Meningioma

Diagnosis typically involves a combination of the following:

Examinations and Tests:

Physical and Neurological Examination:
- A healthcare provider will conduct a thorough physical and neurological exam to assess overall health and specific neurological function.
Imaging Tests:
- Brain MRI (Magnetic Resonance Imaging):
  - MRI with Contrast: This is the most effective imaging test for diagnosing meningiomas. It uses a large magnet, radio waves, and a computer to create detailed images of the brain. The contrast agent, gadolinium, enhances image quality by highlighting specific brain structures.
- CT (Computed Tomography) Scan:
  - If an MRI is not possible, a head CT scan with contrast is an alternative. CT scans use X-rays and computers to create detailed images. The contrast agent highlights certain features, either by ingestion or injection through an IV.
Biopsy:
- In cases where the diagnosis is uncertain, a biopsy may be performed. A neurosurgeon will obtain a small tissue sample from the suspected tumor. This sample is then analyzed to confirm the presence of meningioma, determine if it is benign or malignant, and assign a tumor grade.

Steps in Diagnosis:

Initial Assessment:
- Physical and neurological exams.
- Review of symptoms and medical history.
Imaging Tests:
- MRI with contrast for detailed brain images.
- CT scan with contrast if MRI is not feasible.
Biopsy (if needed):
- Performed to confirm diagnosis and assess tumor characteristics.

Challenges in Diagnosis:

Meningiomas often grow slowly, making diagnosis challenging. Symptoms may be mild or mistaken for normal aging, especially since meningiomas predominantly affect adults. When symptoms do appear, they may have been developing over a long period, complicating early detection.

Referral to a Specialist:

If a healthcare provider suspects a meningioma, they will likely refer you to a neurologist for further evaluation.

Treatments for Meningioma

Treatment depends on the tumor’s size, location, and growth rate. Common approaches include:

Managing meningiomas involves a tailored approach based on individual factors. Treatment options may include:

Observation (“Wait and See”):
- Utilized when the tumor is small, asymptomatic, or poses minimal risk.
- Regular monitoring with MRI scans to track tumor growth.
Surgery (Resection):
- Primary treatment for symptomatic or large meningiomas.
- Goal: Complete removal (Gross Total Resection, or GTR) to potentially cure the majority of cases.
- Factors influencing surgery include tumor location and its relationship with surrounding structures.
Radiation Therapy:
- Used when surgery is not feasible or poses significant risks.
- Types:
  - Stereotactic Radiosurgery (SRS): Precisely targets radiation to the tumor.
  - External Beam Radiation Therapy (EBRT): Directs high-energy beams at the tumor.
  - Brachytherapy: Involves placing radioactive implants near the tumor.
- Adjuvant radiotherapy may be recommended post-surgery for atypical or cancerous meningiomas to prevent recurrence.
Palliative Care: Palliative care focuses on improving quality of life by managing symptoms and supporting patients and their families throughout treatment. It encompasses various interventions, including medication, nutritional support, relaxation techniques, and emotional/spiritual support.
- Essential for managing physical symptoms, side effects, and emotional well-being.
- Includes medication, nutritional support, relaxation techniques, and emotional support.
Chemotherapy: While not commonly used, chemotherapy may be recommended for recurrent or aggressive meningiomas that do not respond to surgery or radiation therapy. Bevacizumab has shown promise in treating anaplastic meningiomas after surgical resection and radiation therapy.
- Rarely used, typically for recurrent or progressive meningiomas.
- Bevacizumab, a type of chemotherapy, may be effective for anaplastic meningiomas post-surgery and radiation therapy.

Home Care Tips

Managing meningioma at home involves supportive care and lifestyle adjustments:

Regular Monitoring: Keep up with follow-up appointments and imaging.
Healthy Diet: A balanced diet can support overall health.
Exercise: Gentle exercise, as tolerated, helps maintain strength and well-being.
Symptom Management: Pain relievers and anti-seizure medications as prescribed.

Complications and Side Effects of Meningioma Treatment

Possible Complications of Meningioma Surgery: Surgery to remove a meningioma, while often effective, carries certain risks and potential complications:

Infection and Bleeding: Standard risks associated with any surgical procedure.
Brain Swelling (Cerebral Edema): May lead to brain damage if not managed promptly.
Injury to Cranial Nerves: Depending on the tumor location, this can affect functions like sight, facial movement, or swallowing.
Fluid Buildup around the Brain: Can result in cerebral edema and subsequent brain damage.
Damage to Normal Brain Tissue: Accidental injury during surgery may impact cognitive functions, vision, or speech.

Possible Side Effects of Radiation Therapy:

Radiation therapy, while painless during treatment, can lead to temporary or permanent side effects when healthy tissues are exposed to radiation:

Skin Reactions and Hair Loss: Common but usually temporary.
Fatigue: May persist during and after treatment.
Cognitive Changes: Such as difficulty thinking clearly and mild memory loss; some may be permanent.
Loss of Appetite: Can occur during treatment.
Headaches: May experience headaches as a side effect.

Possible Side Effects of Chemotherapy:

Chemotherapy, if used for meningioma treatment, can cause various side effects depending on the drug and dosage:

Fatigue: Persistent tiredness is common.
Increased Risk of Infection: Due to lowered immune function.
Nausea and Vomiting: Common side effects, but can often be managed with medications.
Hair Loss: Usually temporary.
Loss of Appetite and Diarrhea: May occur during treatment.

Prevention of Meningioma

While meningiomas cannot be entirely prevented, certain measures might reduce risk:

Limit Radiation Exposure: Avoid unnecessary radiation, particularly to the head.
Genetic Counseling: For those with a family history of meningiomas.

Long-Term Complications of Meningioma

Meningioma and its treatment can lead to enduring complications, such as:

Difficulty concentrating and memory loss.
Personality changes
Seizures.
Weakness and language difficulties.

When to See a Doctor

Seek medical attention if you experience persistent headaches, seizures, vision changes, or other neurological symptoms. Early detection and intervention can significantly impact outcomes.

Outlook/Prognosis.

it’s crucial to recognize that each person’s experience with meningioma is unique. Predicting how it will affect you specifically can be challenging. Consulting with healthcare professionals specializing in meningioma care can offer personalized insights into your prognosis.

Prognosis Factors: Several factors influence the prognosis for meningioma, including:

Tumor Size and Location: Determines the impact on surrounding structures.
Tumor Type: Whether the tumor is benign or malignant.
Extent of Surgical Removal: Complete removal is associated with better outcomes.
Age and Overall Health: Younger age generally correlates with improved prognosis.

Sources

American Brain Tumor Association
National Institute of Neurological Disorders and Stroke
Mayo Clinic
Johns Hopkins Medicine
Cleveland Clinic
National Center for Advancing Translational Sciences
American Society of Clinical Oncology (ASCO)
American Association of Neurological Surgeons.