Glioblastoma (GBM) - The Most Aggressive Brain Tumour and Microsurgery

Glioblastoma (GBM) is the most common high-grade (WHO Grade 4) malignant brain tumour in adults. It is known for its rapid growth, tendency to spread within brain tissue, and resistance to treatment. However, with the possibilities offered by modern neurosurgery, significant steps are being taken in the fight against this challenging disease.

What is GBM?

GBM is a primary brain tumour of glial origin, meaning it originates from the brain's support cells. It accounts for approximately 15 percent of all primary brain tumours and about half of all malignant brain tumours.^1,2 The average age of diagnosis is between 55-65, and it is seen slightly more frequently in men than in women.³

How Do Symptoms Begin?

GBM symptoms depend on the location and growth rate of the tumour. Headache is the most common complaint; it is usually persistent, progressively worsening, and more pronounced in the mornings. Having seizures, loss of strength in an arm or leg, difficulty speaking or understanding, and balance and personality changes are among other common symptoms.

The important point is this: these symptoms usually appear within a few weeks to a few months and progress rapidly. This rapid course reflects the aggressive nature of GBM.

The Diagnostic Process

Contrast-enhanced brain MRI plays a fundamental role in diagnosis. GBM is typically seen as a ring-enhancing mass with surrounding oedema and containing necrosis. However, imaging alone cannot provide a definitive diagnosis; pathological examination is essential.

There is a critical point of distinction here: the patient's condition and the location of the tumour determine whether a biopsy or surgical resection will be performed. Both approaches have different advantages and risk profiles.

The Microsurgical Approach

In suitable cases, as much tumour tissue as possible is removed with microsurgery. The goal here is to achieve maximum safe resection while preserving neurological functions. The surgeon's experience, the use of neuronavigation, intraoperative monitoring, and awake surgery when necessary are components of this process.

The concept of maximum safe resection is important: while removing the largest possible portion of the tumour, the aim is to preserve the patient's motor, sensory, and cognitive functions. Research has shown that more extensive resection significantly prolongs survival.^4,5

When is a Biopsy Preferred?

If the tumour is deep-seated, located in eloquent (critical functional) areas, if the patient's general condition is not suitable for surgery, or if pathological evaluation is required for a definitive diagnosis, a stereotactic biopsy may be preferred. A biopsy is the procedure of taking a tissue sample with a needle under navigation guidance through a small hole (burr hole).

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