What is Meningioma
Meningioma is a generally benign tumor of the meninges (the tissues that line and protect the central nervous system). It can compress adjacent brain tissues and manifest as a solitary lesion or in multiple lesions. It is one of the most common tumors of the central nervous system.
It most commonly affects people between 40 and 60 years old but can occur from childhood to advanced age. It is the most frequent brain tumor among women.
The tumor can develop in any part of the dura mater but most often occurs on the convex parts, near the venous sinuses, at the base of the skull, in the posterior fossa, and in the ventricles. It does not directly invade the brain but can compress it and/or the cranial nerves, potentially blocking the absorption of cerebrospinal fluid.
The causes of cerebral meningioma are not well defined.
Subtypes of meningioma
Meningiomas are classified into three grades by the World Health Organization (WHO) according to their characteristics, which are:
- Meningioma grade I – benign tumor with slow growth, is the most common of the three types;
- Meningioma grade II – atypical and benign tumor that presents a higher risk of recurrence after removal; and
- Meningioma grade III – atypical and cancerous tumor that grows rapidly.
Symptoms and signs of meningioma
Many meningiomas are asymptomatic. When they do present symptoms, they often depend on the location of the tumor:
- Symptoms of meningioma in the frontal region of the head – loss of vision, loss of smell, and behavioral changes;
- Symptoms of meningioma in the posterior region of the head – coordination difficulties; and
- Symptoms of meningioma at the base of the skull – difficulty speaking, swallowing, or moving the tongue.
There are symptoms of meningioma common to all locations where it may occur: headache, vomiting, loss of strength, and loss of sensitivity. Neurological symptoms related to the spine may also indicate the presence of a meningioma.
In older people, it can cause dementia.
Meningioma Diagnosis
The diagnosis of meningiomas, like other brain tumors, is made by magnetic resonance imaging with paramagnetic contrast.
Computerized tomographies or simple radiographs performed for other reasons may indicate bone abnormalities (such as cerebral atrophy, hyperostosis around cerebral convexities, changes in the sellar tubercle) and incidentally indicate the presence of a meningioma.
Meningioma Cancer Treatment
Asymptomatic and small tumors, especially in elderly people, do not require treatment. Follow-up with periodic imaging exams is sufficient, such as those performed at Oncoclínicas.
Grade I meningiomas are treated only with surgery and observed, as the risk of recurrence is low. Grade II and III meningiomas, on the other hand, present a higher risk of local recurrence, requiring post-surgical complementary treatment with radiotherapy.
Radiotherapy can be used with IMRT (intensity-modulated radiation therapy) technique and conventional fractionation (small dose per day for 30 days) or with stereotactic radiosurgery technique (conformation to the tumor, reducing the dose margin around with maximum precision and high doses in few or a single day).
Its choice, as well as the total and daily dose, is made by the specialist doctor (radiation oncologist) after careful evaluation of each case.
In cases where surgery may cause more harm than the tumor, and therefore is contraindicated, exclusive radiotherapy can be used for treatment. These cases include:
- Large meningiomas;
- Invasion of blood vessels (usually adjacent veins); and
- Proximity to critical brain regions (such as the brainstem).
Prevention for Brain Meningioma
Since the cause of meningioma is not defined, there are no means to prevent it.
