From the Guidelines
Most meningiomas are benign tumors, accounting for about 90% of cases, as classified by the World Health Organization (WHO) as Grade I. These slow-growing tumors develop from the meninges, the protective membranes covering the brain and spinal cord. While they are classified as benign, approximately 6-8% are atypical (WHO Grade II) with more aggressive features, and 1-3% are malignant (WHO Grade III) 1. Even benign meningiomas can cause serious symptoms depending on their location, potentially pressing on the brain, nerves, or blood vessels. Symptoms may include headaches, seizures, vision problems, or weakness in limbs.
Key Characteristics of Meningiomas
- They are slow-growing tumors
- Develop from the meninges
- Classified as benign (WHO Grade I), atypical (WHO Grade II), or malignant (WHO Grade III)
- Can cause symptoms based on location
Treatment options vary based on size, location, and symptoms, ranging from observation with regular imaging for small asymptomatic tumors to surgical removal for larger or symptomatic ones. Radiation therapy may be used for incomplete surgical removal or higher-grade tumors. The overall prognosis for benign meningiomas is generally good, with a high rate of successful treatment, though regular follow-up is important as recurrence can occur even years later 1.
Treatment and Prognosis
- Treatment options include observation, surgery, and radiation therapy
- Prognosis is generally good for benign meningiomas
- Regular follow-up is necessary due to the risk of recurrence
Recent studies have provided more insight into the molecular characteristics of meningiomas, including the role of copy-number alterations and specific genetic mutations in determining the grade and prognosis of these tumors 1. However, the integration of these molecular findings into clinical practice is still evolving, and more research is needed to fully understand their implications for patient management.
Molecular Characteristics and Future Directions
- Molecular characteristics, such as copy-number alterations and genetic mutations, are being studied for their role in determining tumor grade and prognosis
- Integration of molecular findings into clinical practice is ongoing
- Further research is needed to understand the implications for patient management
From the Research
Definition and Classification of Meningiomas
- Meningiomas are generally considered to be benign tumors, but they can be classified into different grades, with Grade I being the most common and considered typical or benign 2.
- However, some meningiomas can exhibit aggressive behavior and be classified as atypical (Grade II) or anaplastic (Grade III), which are considered malignant 2, 3.
Characteristics of Benign Meningiomas
- Benign meningiomas (Grade I) are extremely slow-growing tumors, and many are asymptomatic or paucisymptomatic at diagnosis 2.
- They are more common in females, with a female-to-male ratio of approximately 2 or 3:1, and the median age at diagnosis is 65 years 2.
- The treatment of choice for benign meningiomas is complete microsurgical resection, which can result in a high ten-year net survival rate of over 80% 2.
Aggressive and Malignant Meningiomas
- Atypical (Grade II) meningiomas are considered "intermediate grade" malignancies and represent 5-7% of cases, with a tendency for recurrence and malignant degeneration 2.
- Anaplastic (Grade III) meningiomas are rare, representing only 1-3% of cases, and are characterized by a poor prognosis with a ten-year net survival rate of 15% 2.
- The treatment for aggressive and malignant meningiomas often involves a combination of surgery, radiation therapy, and other approaches, such as stereotactic radiosurgery and chemotherapy 3, 4, 5.
Treatment and Management
- The treatment of meningiomas depends on various factors, including the tumor's location, size, and grade, as well as the patient's age and overall health 2, 3, 4.
- A "watchful waiting" strategy may be considered for extremely old individuals or those with substantial comorbidities, while a more proactive approach may be taken for relatively healthy younger individuals 2.
- Adjuvant radiosurgery or radiotherapy may be recommended for patients with atypical or anaplastic meningiomas, especially when a residual tumor is identifiable in postoperative imaging 2, 5.