There are different types; some are benign, and others are malignant (cancerous). Most malignant tumours are due to the spread (metastasis) of cancer located elsewhere in the body, with malignant tumours originating from the brain itself being more infrequent. Brain tumours can be classified into:
Brain metastases. They are the most common cause of malignant brain tumours in adults. Metastases are due to the extension of a tumour located in another area of the body, usually lung cancer, breast cancer or melanoma. They typically appear in patients who know that they have cancer in a specific place, although sometimes brain metastases are the first manifestation of the presence of cancer that they did not know they had.
Primary brain tumours. There are a lot of types:
Gliomas, such as astrocytoma, oligodendroglioma, or oligoastrocytoma.
Central nervous system lymphoma.
Brain tumours arise from structures adjacent to (near) the brain, such as meningiomas and schwannomas.
What are the causes of brain tumours?
As in most cancers, the factors that lead to the appearance of brain tumours are not known:
Primary brain tumours have been linked to ionising radiation.
Brain lymphomas have been related to lowered defences, for example, in AIDS patients.
There are some syndromes in which the frequency of brain tumours is very high, such as neurofibromatosis, von Hippel-Lindau disease, etc.
There is currently no evidence that electromagnetic radiation, including exposure to mobile phones, is associated with an increased risk of brain tumours.
What symptoms does the development of these tumours produce?
The symptoms of brain tumours depend on the rate of growth of the tumour and its location. In general, they can produce:
Alterations in the level of consciousness, with a tendency to sleep. They are more frequent in the most aggressive and rapidly expanding tumours, such as metastases and rapidly evolving malignant primary brain tumours.
Personality changes, such as apathy and lack of interest in relationships. They can simulate depression.
A deficit in some motor capacity (loss of strength in an arm, in a leg, in one half of the body, inability to speak, etc.) or sensory ability (tingling in an arm or leg). The sudden onset of a motor deficit can lead to suspicion of stroke and is more characteristic of more aggressive tumours and metastases.
Balance disturbances.
Sight loss. More common in metastases.
Headache It is usually more intense in the morning and does not respond adequately to taking painkillers.
Epileptic seizures. They are more common in slow-growing tumours, such as low-aggressive malignant tumours, although they can also appear in aggressive tumours and metastases.
Types of brain tumours and their characteristics
Astrocytomas. They are classified in:
Low-grade astrocytomas. They appear mainly in children and young people:
- Grade I astrocytoma (pilocytic astrocytoma). It is the most common in children. It is usually located in the cerebellum, although it can affect anywhere in the central nervous system. They can be cured if they can be removed entirely with surgery.
- Grade II astrocytoma (diffuse astrocytoma). They usually debut as an epileptic seizures in a young person.
- High-grade astrocytomas.
- Grade III astrocytoma (anaplastic astrocytoma). They usually appear between 30 and 50 years of age.
Oligodendroglioma grade II or well differentiated. It usually appears in young people and frequently debuts as an epileptic seizure.
Grade III or anaplastic oligodendroglioma. It appears in people between 30 and 50 years old.
Oligoastrocytombly is located in the spinal cord.
Meningiomas. They are generally benign tumours from the meninges, the layers surrounding the brain and spinal cord. It is the most common type of brain tumour and is often a casual finding in people, generally the elderly, who undergo a CT or MRI for any other reason. They can produce symptoms such as headache, seizures or motor deficits. They are classified in:
- Grade I. Benign.
- Grade II. Atypical meningioma.
- Grade III. malignant meningioma.
Schwannomas. They are usually benign tumours that affect the nerves of the ear or face. They are prevalent in patients with neurofibromatosis. Those that affect the ear can be an incidental finding or cause deafness, vertigo or noise in the ears (tinnitus).
Hypothalamic tumours. The hypothalamus is an area involved in the control of numerous hormones in our body. Tumours at the level of the hypothalamus are usually benign. They are manifested by various endocrine disorders, such as excessive bone growth (acromegaly), mammary milk production ( galactorrhea ), Cushing’s syndrome, infertility, etc. Given their location, they can also cause headaches and visual disturbances by compressing the nerve of sight.
Craniopharyngiomas. They are rare, benign tumours that affect children or people over 50 years of age. They cause headaches, vision disturbances and, in children, growth disturbances.
How are they diagnosed?
A brain tumour diagnosis is made by performing a CT scan or, preferably, a brain MRI. Other tests such as PET may be necessary for differentiating the tumour from the dead tissue around it. In patients with brain metastases, additional tests are required to locate the original tumour if it was not previously identified.
Are these types of tumours hereditary?
Some hereditary diseases are associated with an increased risk of brain tumours, such as von Hippel Lindau disease, neurofibromatosis, multiple endocrine neoplasias, tuberous sclerosis, etc.
Can they be prevented?
Brain tumours cannot be prevented.
What is the diagnosis of the illness?
Metastatic tumours and malignant primary brain tumours generally have a poor prognosis. Median survival in a patient with glioblastoma (grade IV astrocytoma) is approximately 18 months and usually shorter (depending on the type of primary tumour) in a patient with brain metastases. The survival of oligodendrogliomas is much higher, frequently over ten years in type II and 6 or 7 years in grade III.
What is your treatment?
- The treatment of brain tumours should be differentiated into:
- Treatment of symptoms:
- To reduce the headache, in addition to analgesics, it may be necessary to administer corticosteroids (dexamethasone) and thus reduce the inflammatory area around the tumour. This treatment also improves neurological deficits.
- In cases of epileptic seizures, it is necessary to administer anti-epileptic drugs.
- Treatment of the tumour itself. Depending on the type of tumour, chemotherapy, radiotherapy, or surgery may be used.
- – Astrocytomas. Treatment is surgery as extensive as possible, followed by radiation therapy in grades II to IV. In grades III and IV, chemotherapy is also used and is currently being tested in less aggressive cases. Glioblastomas often recur (come back). In these cases, surgery can be performed again, or treatment with other medicines (immunotherapy) can be used. There is a large number of investigational drugs.
- Oligodendrogliomas and oligoastrocytomas. Grade II tumours respond better to treatment than astrocytomas. They are treated with surgery and, if necessary, radiotherapy and chemotherapy. Those in grade III have a worse prognosis. Some of these tumours have a mutation that makes them especially sensitive to chemotherapy and radiotherapy.
- Ependymomas. They can be cured if they can be removed entirely; otherwise, they usually reappear, having to re-operate or receive radiotherapy.
- Meningiomas. If they are large or produce symptoms, it may be necessary to operate on them, curing them entirely if they are removed. If not, they can grow back. They can also be treated with radiation therapy.
- Schwannomas are treated with conventional surgery or stereotactic radiosurgery.
- Tumors of the hypothalamus. The treatment is surgical, generally transsphenoidal (through the nose)
- Craniopharyngiomas. Treatment is with surgery or radiotherapy.
Brain metastases. Your treatment depends on the type of primary cancer causing the metastases and whether it is a single or multiple metastases. The usual treatment has been the administration of intravenous and oral corticosteroids (dexamethasone) associated with whole-brain radiotherapy. It is not a curative treatment, and survival is poor. Several techniques have recently been developed to administer localised radiotherapy (stereotactic radiosurgery using proton beams, linear accelerator, gamma knife surgery, etc.) in the tumour area, allowing a higher intensity of radiation to be administered with less damage to the structures. Neighbouring brains. This treatment can only be performed on tumours smaller than 3 cm but can be curative. Single metastases can also be treated with surgery followed by radiation therapy.
Although a medical specialist has written this information, its edition has been carried out by journalists, so it is merely indicative content and without the value of therapeutic or diagnostic indication.
