Symptoms

The first clinical symptoms appear after a few weeks or even earlier. Headaches (35%), epileptic seizures (30%) and psychological changes (16%) are the most common initial symptoms. Increased intracranial pressure due to the space-occupying effect of the tumor and the associated disturbance of the cerebrospinal fluid flow (cerebrospinal fluid circulation) causes headaches, nausea, vomiting and swelling (edema) of the exit site of the optic nerve (congestion papilla), which can lead to visual disturbances.

Paralysis can also occur due to the expansion of the tumor. Seizure-like worsening of the symptoms is due to tumor bleeding (apoplectic glioma) and is not uncommon. In computed tomography (CT), glioblastomas are characterized by varying density, blurred tumor boundaries, central necrosis within the tumor and a large edema around the tumor (peritumoral edema).

After administration of the contrast medium, a substance that increases the image contrast, an accumulation (accumulation) of the contrast medium occurs, especially in the marginal zone of the tumor. In the case of small tumors, a ring structure becomes visible, in larger tumors a garland formation. Tumor hemorrhages are visible in about 7% of glioblastomas.

The MRI of the brain shows the spread of the tumor, partly across the bar. After administration of contrast medium, the contrast medium accumulates in the solid tumor parts. The typical MRI image of a glioblastoma also includes residual bleeding and an extensive finger-shaped peritumoral edema.

However, it can be difficult to distinguish between a large, necrotic brain metastasis and a brain abscess. Angiography can be performed additionally, but is no longer a standard diagnostic procedure for glioblastoma. In this procedure, contrast medium is injected into the blood vessels and the vessels are visualized using diagnostic imaging techniques such as X-rays or MRI.

Angiography in glioblastomas shows an accumulation of contrast medium in the pathological vessels in 60-70% of cases. The veins draining from the tumor are already displayed during the arterial phase (“early veins”), which shows the too fast flow of blood into the veins through the arteriovenous anastomoses. The suspicion of a glioblastoma is often raised by means of an imaging procedure.

In most cases, this is magnetic resonance imaging. The typical finding shows a tumor without a homogeneous (uniform) structure. The solid parts (fixed parts) are very well supplied with blood and therefore absorb a lot of contrast medium.

This is noticeable at first glance. They are very bright and literally glow on the MRI image. In addition, there are always contrast medium recesses (areas that do not appear bright on the MRI).

These are cystic parts or dead cell clusters (necroses), these are not supplied by a blood vessel and therefore cannot absorb contrast medium. The tumor is usually immediately visible as an edema (swollen cells). Often the space-occupying effect of the tumor is already visible at the first diagnosis, i.e. the midline is already shifted by the tumor growth.For the final diagnosis, however, a sample must be taken and examined under a microscope. Only the pathologist can confirm the diagnosis of a glioblastoma.