From the Guidelines
Most cerebral meningiomas are not malignant, with approximately 90% being benign (WHO grade I) and only about 1-3% being truly malignant (WHO grade III) 1. When considering the management of cerebral meningiomas, it's crucial to understand their classification and potential impact on patient outcomes, particularly in terms of morbidity, mortality, and quality of life.
Key Considerations
- The World Health Organization (WHO) grading system is used to classify meningiomas into three grades: Grade I (benign), Grade II (atypical), and Grade III (malignant) 1.
- The treatment approach varies based on the tumor size, symptoms, and WHO grade, with options including observation, surgery, and radiation therapy 1.
- For small, asymptomatic meningiomas, observation is often the preferred initial approach, especially if the tumor is less than 30 mm in size and has no potential neurologic consequences 1.
- Symptomatic or larger meningiomas may require surgical intervention, potentially followed by radiation therapy, especially if the tumor is of a higher grade or if there's incomplete resection 1.
Treatment Implications
The choice of treatment significantly affects patient outcomes in terms of morbidity, mortality, and quality of life.
- Surgery is considered for accessible tumors, with the addition of radiation therapy for WHO grade 3 tumors or in cases of incomplete resection for WHO grade 1 or 2 tumors 1.
- The decision-making process should involve multidisciplinary input to ensure the best possible outcome for the patient, considering factors such as tumor size, location, grade, and the patient's overall health status 1.
- Participation in clinical trials is encouraged, as it may offer access to novel treatments that could improve outcomes for patients with cerebral meningiomas 1.
From the Research
Cerebral Meningioma Classification
- Meningiomas are divided into three grades: Grade I (benign), Grade II (atypical), and Grade III (anaplastic/malignant) 2, 3
- Grade I represents the vast majority of cases and is considered typical or benign 2
- Grade II and Grade III meningiomas are considered malignant and have a higher tendency for recurrence and malignant degeneration 2, 3
Malignancy of Cerebral Meningioma
- The majority of meningiomas are benign, but a small percentage can be malignant 2, 3
- Atypical (WHO grade II) meningiomas are considered "intermediate grade" malignancies and represent 5-7% of cases 2
- Anaplastic (WHO grade III) meningiomas represent only 1-3% of cases and are characterized by a poor prognosis 2
Treatment Options
- Treatment options for meningiomas include surgery, radiosurgery, fractionated radiation therapy, or a combination of these modalities 4, 5, 6
- The treatment of choice for meningiomas is complete microsurgical resection, but other approaches such as stereotactic radiosurgery and radiotherapy may be considered in certain cases 2, 5
- Adjuvant radiosurgery/radiotherapy should be considered in the case of atypical and anaplastic histology, especially when a residual tumor is identifiable in postoperative imaging 2