We generally group together under the term " Cerebral tumors ", real brain tumors, but also tumors of the envelopes (meninges, skull, etc.) which are not strictly speaking brain tumors.
Intracranial extracerebral tumors ultimately manifest as intracerebral tumors because they compress the healthy brain, which explains the historical regrouping of these two entities.
Both brain tumors and extracerebral tumors include primary tumors and secondary tumors (metastases).
The incidence of primary brain tumors is approximately 6 new cases per year per 100,000 inhabitants. At the Swiss level (8,600,000 inhabitants in 2018), this therefore represents 516 new cases per year.
The localization of brain tumors is mainly supratentorial in adults while it is mainly infratentorial in children.
The clinical presentation will depend essentially on 3 factors:
Destruction of brain tissue
Local metabolic changes
Both the destruction of brain tissue and the mass effect can generate focal neurological deficits (motor, sensory or neuropsychological).
Epileptic seizures are mainly due to local metabolic changes which generate "electrical" disturbances at the origin of the seizures.
Intracranial hypertension is a rather late manifestation linked to 3 main factors:
Obstruction of CSF circulation
Intracranial hypertension manifests itself with headache, reduced visual acuity, vomiting, and ultimately disturbances in consciousness.
However, do not be alarmed by headaches (cephalgias) because these will almost never be the first manifestation of a brain tumor. The most frequent causes are migraines and tension headaches (often linked to cervical pathologies).
Gliomas are tumors that arise from the supporting cells of the nervous system. There is quite a gradation in the malignancy-benignity of these tumors.
We must not lose sight of the fact that their location (in a critical area or not of the brain) can be just as important.
The natural evolution of low-grade gliomas is unfortunately an inevitable transformation into glioblastoma by successive mutations.
The CT scans opposite illustrate a temporal glioblastoma before and after surgical excision.
Glioblastomas are tumors which take up contrast in an intense and heterogeneous manner (linked to areas of necrosis) and cause a marked mass effect.
Glioblastomas can be confused on both CT-scan and MRI with metastases or with abscesses.
Unfortunately, the treatment of glioblastomas is hardly ever curative at the present time, however survival and the quality of survival have improved considerably over the past ten years by combining treatments.
Complete resection of the tumor is a crucial step, but it is not always possible depending on the location of the glioblastoma (for example partly in an area of the tongue). The notion of complete resection is macroscopic, because at the microscopic level, there are always other tumor foci. Therefore, systemic treatment of the whole brain is required in all cases.
Treatment of the entire brain of patients with glioblastoma is through radiation therapy (in high doses, but divided) and chemotherapy. Immunological treatments are also under investigation.
Glioblastomas, like metastases, sometimes have large cysts with a significant mass effect. These cysts can possibly be the subject of a palliative treatment in the form of implantation of a drain (for example if the patient cannot or does not want to undergo a major intervention). However, these are quite rare situations.
Pituitary adenomas are benign tumors.
Some adenomas will be secreting (prolactin, growth hormone, etc.) while others will only appear through their mass effect on the pituitary stem or on the optic chiasma mainly.
The bust opposite illustrates the clinical manifestations of acromegaly caused by a pituitary adenoma producing growth hormone (GH).
This coronal MRI with gadolinium demonstrates the intense contrast enhancement of the hyophyseal adenoma and the relationship with the cavernous sinuses (the internal carotid arteries appear in black in this sequence).
There are basically 4 treatment options for pituitary adenomas:
Clinical and radiological monitoring
Drug treatment for braking