Low Grade and High Grade Glioma Tumors

Gliomas (glial tumors), which constitute an important group among brain and nervous system tumors, originate from glial cells that support brain tissue. These tumors are generally classified into two main groups according to their structure and growth rate: low-grade gliomas and high-grade gliomas. There are significant differences between these two groups in terms of disease progression, treatment approach, and prognosis.

With many years of experience in neurosurgery, Prof. Dr. Ömür Günaldı emphasizes that early diagnosis of gliomas directly affects treatment success and that proper grading of the tumor is essential for determining the most effective treatment strategy.

What Is Glioma?

A glioma is a tumor that develops from glial cells, the supporting cells of the brain. These cells protect neurons, nourish them, and regulate communication within the nervous system. When glial cells multiply abnormally, a glial tumor or glioma develops.

Prof. Dr. Ömür Günaldı explains that gliomas should be classified not only according to their location in the brain but also according to their cellular structure and genetic characteristics.

Gliomas usually originate from three main types of glial cells:

Astrocytoma: Develops from astrocytes.

Oligodendroglioma: Originates from oligodendrocytes that produce the myelin sheath surrounding nerve fibers.

Ependymoma: Arises from ependymal cells responsible for producing cerebrospinal fluid.

Depending on the differentiation level of these cells, gliomas are categorized as low-grade or high-grade tumors.

Low-Grade Gliomas

Low-grade gliomas are slow-growing tumors that generally show a more benign course. Under microscopic examination, the tumor cells resemble normal brain cells, which explains their slower growth rate and limited spread to surrounding tissues.

Prof. Dr. Ömür Günaldı states that when low-grade gliomas are diagnosed early, they can often be completely removed through surgery, allowing patients to live healthy lives for many years.

Types of Low-Grade Gliomas

Pilocytic Astrocytoma (Grade I):
Commonly seen in children. It grows slowly and the recurrence risk is low after complete surgical removal.

Low-Grade Astrocytoma (Grade II):
Often occurs in young adults. Although the cell structure is relatively regular, it carries the risk of malignant transformation over time.

Oligodendroglioma (Grade II):
Usually progresses slowly and may remain stable for many years in some patients.

Symptoms of Low-Grade Gliomas

Because these tumors grow slowly, symptoms may not appear immediately. Over time, patients may experience:

Recurrent headaches
Vision or speech disturbances
Balance problems
Memory difficulties
Seizures

Prof. Dr. Ömür Günaldı explains that seizures are often the first sign of low-grade gliomas and that any unexplained seizure should always be evaluated by a neurologist.

Diagnosis of Low-Grade Gliomas

The most commonly used diagnostic method is Magnetic Resonance Imaging (MRI). The tumor typically appears as a well-defined, non-enhancing mass.

For a definitive diagnosis, biopsy is required.

Genetic analyses such as IDH mutation and 1p/19q deletion are also important in predicting tumor behavior.

Prof. Dr. Ömür Günaldı emphasizes that biopsy results guide both diagnosis and treatment planning.

Treatment of Low-Grade Gliomas

Surgery is the primary treatment. The goal is to remove as much of the tumor as possible.

If small tumor remnants remain after surgery, regular monitoring is required. In some cases, radiotherapy or chemotherapy may be recommended.

Prof. Dr. Ömür Günaldı explains that neuronavigation systems allow surgeons to preserve critical brain areas during surgery and reduce the risk of permanent neurological damage.

Life Expectancy in Low-Grade Gliomas

Survival rates are relatively high. With proper surgical treatment and follow-up, patients may live 10 years or longer.

However, if not monitored regularly, low-grade gliomas may transform into higher-grade tumors.

High-Grade Gliomas

High-grade gliomas are aggressive and malignant tumors. Their cells divide rapidly, invade surrounding brain tissue, and often recur after treatment.

Prof. Dr. Ömür Günaldı explains that high-grade gliomas are often diagnosed at advanced stages and require a multidisciplinary treatment approach.

Types of High-Grade Gliomas

Anaplastic Astrocytoma (Grade III):
These tumors grow at a moderate to high rate and show cellular abnormalities under microscopic examination.

Glioblastoma Multiforme (GBM, Grade IV):
The most aggressive type of glioma. It spreads deeply into brain tissue and has the highest recurrence risk.

Genetic alterations such as EGFR amplification and PTEN loss are commonly seen in these tumors, contributing to treatment resistance.

Symptoms of High-Grade Gliomas

Symptoms often appear rapidly and can be severe:

• Severe persistent headaches
• Nausea and vomiting
• Vision loss or double vision
• Memory problems
• Personality changes
• Weakness in the arms or legs
• Loss of consciousness or seizures

Prof. Dr. Ömür Günaldı explains that the rapid onset of symptoms reflects the aggressive growth of the tumor.

Diagnosis of High-Grade Gliomas

Advanced imaging methods such as MRI, MR spectroscopy, and PET scans are used for diagnosis.

Biopsy reveals key features such as rapid cell division, nuclear abnormalities, and necrosis.

Genetic markers such as IDH mutation and MGMT methylation also help predict treatment response.

Treatment of High-Grade Gliomas

Surgery is the main treatment. However, complete removal is often difficult because the tumor spreads into surrounding brain tissue.

After surgery, radiotherapy and chemotherapy (temozolomide) are typically applied.

Prof. Dr. Ömür Günaldı states that targeted therapies and immunotherapy may also be used in selected patients to extend survival.

Neurological rehabilitation programs may also help preserve cognitive and physical functions after surgery.

Life Expectancy in High-Grade Gliomas

In these tumors, survival is generally limited.

In glioblastoma patients, average survival ranges from 12 to 24 months.

However, with early diagnosis, maximal surgical removal, and advanced treatment combinations, survival may extend to 3–5 years.

Prof. Dr. Ömür Günaldı emphasizes that the goal of treatment is not only tumor control but also improving the patient’s quality of life.

Differences Between Low-Grade and High-Grade Gliomas

Growth Rate:
Low-grade tumors grow slowly, while high-grade tumors spread rapidly.

Cell Structure:
Low-grade tumors have more regular cells; high-grade tumors show abnormal and irregular cells.

Treatment Approach:
Surgery is often sufficient for low-grade tumors, while high-grade tumors require additional therapies.

Survival:
Longer in low-grade tumors and shorter in high-grade tumors.

Recurrence Risk:
Lower in low-grade tumors but significantly higher in high-grade tumors.

Prof. Dr. Ömür Günaldı emphasizes that each glioma has unique biological behavior and therefore treatment should always be individualized.

Lifestyle and Follow-Up in Glioma Patients

After treatment, maintaining quality of life requires healthy nutrition, regular monitoring, and psychological support.

Prof. Dr. Ömür Günaldı recommends that glioma patients follow an antioxidant-rich diet, avoid smoking and alcohol, and manage stress effectively.

Regular MRI scans help detect recurrence early.

Typically, follow-up imaging is recommended:

Every 6 months for low-grade gliomas

Every 3 months for high-grade gliomas

While low-grade gliomas often behave benignly and can sometimes be completely removed surgically, high-grade gliomas show aggressive behavior and usually require combined treatments.

With extensive experience in neurosurgery, Prof. Dr. Ömür Günaldı emphasizes that glioma patients should be diagnosed early, monitored regularly, and treated using a multidisciplinary approach.

Early detection of glioma significantly increases the chances of achieving a longer and better quality life.