Oligodendroglioma: symptoms, diagnosis and treatment

Cancer Research UK explains that oligodendrogliomas develop from glial cells called oligodendrocytes. These cells make myelin, a fatty white substance that covers nerves and helps signals travel along them more quickly. The tumours are mostly found in the frontal lobe of the brain, and they can rarely start in the spinal cord or spread to other parts of the brain and spinal cord.

The Brain Tumour Charity describes oligodendroglioma as a primary brain tumour, meaning it starts in the brain rather than spreading there from elsewhere, and as the third most common of all gliomas. It says they are slightly more common in men than women. After the frontal lobe, the temporal and parietal lobes are the next most common sites.

Doctors group brain tumours using a system that the World Health Organization regularly updates. Cancer Research UK says its information is based on the 2021 WHO classification, in which a glioma is diagnosed as an oligodendroglioma only if the cells have a mutation in the IDH gene and are missing parts of chromosome 1 (1p) and chromosome 19 (19q), which is why they are called IDH mutant and 1p/19q co-deleted.

These tests are sometimes called biomarkers or molecular studies. They are done on the tumour cells, which is one reason a biopsy is part of the diagnostic tests.

Cancer Research UK says symptoms depend on where the tumour is in the brain. The Brain Tumour Charity lists the most common as seizures and headaches, with altered sensations and muscular weakness, and notes that these tumours can cause gradual changes in mood or personality, or speech and language problems when they are in the frontal lobe.

• Seizures (fits), often the first sign.

• Headaches.

• Weakness or numbness, particularly down one side of the body.

• Feeling or being sick.

• Gradual changes in mood or personality, speech and language problems, or memory problems depending on the lobe affected.

Cancer Research UK says that if you have a seizure it is important to see a doctor or go to A&E immediately, and that the symptoms of brain tumours are often caused by other medical conditions but it is important to see a doctor if you have any of them. It notes that it is unlikely you have a brain tumour if headaches are your only symptom, but advises seeing a doctor if headaches come with sickness, are new, wake you at night, come with eye problems or steadily worsen over weeks.

Symptoms can develop gradually over months or even years if the tumour is slow growing, or quickly over days or weeks if it is fast growing.

Cancer Research UK says tests may include an MRI or CT scan, a biopsy and a neurological examination. The doctor checks the size and location of the tumour, which helps plan treatment. The tumour tissue is examined to determine the type, grade and gene changes.

The grade describes how quickly the tumour is likely to grow, with more normal-looking cells meaning a lower grade, and also depends on genes and proteins in the cells. Oligodendrogliomas are grouped as grade 2 (low grade, sometimes called diffuse) or grade 3 (high grade, sometimes called anaplastic).

Treatment depends on whether the tumour is low grade or high grade. The main treatments are surgery to remove as much tumour as possible, radiotherapy and chemotherapy. Oligodendrogliomas tend to grow into the surrounding brain tissue without a clear border, which can make complete removal difficult.

The Brain Tumour Charity says that treatment can range from watch-and-wait to neurosurgery, radiotherapy and chemotherapy, and that it offers an information pack, a support team and online groups. Your clinical team can advise on practical issues and on what support is available locally.

Cancer Research UK also notes that it is common to struggle with your mental health when you have cancer or care for someone with cancer, and provides information and a nurse helpline. If you have seizures, you will be given advice about safety and driving by your team, which the sources read here do not set out in detail.

Brain tumours are managed in NHS neuro-oncology services, where specialist teams, including a neurosurgeon, plan treatment. Treatment, including radiotherapy and chemotherapy such as PCV, is free at the point of use.

Some people ask for a private opinion with a neurosurgeon or neuro-oncologist, mainly for a second view or faster appointments. A second opinion usually involves sharing scans and pathology results. Ask each team who is coordinating your care.