Hemangioblastoma

Firstly, what even is a tumour?

So, a solid tumour is an abnormal mass of cells that grows on human tissue. We call these cells ‘neoplastic’, meaning ‘new growth’ – these growths are neither requested nor required.

We usually distinguish between malignant and benign tumours. Cancerous tumours can be malignant, and so they can proliferate or spread. Conversely, benign tumours grow slower and don’t usually spread. This is because their cells behave more like normal cells rather than cancer cells.

Brain tumours vary depending on the type of brain cells affected; some are benign, while others are more aggressive.

What’s a hemangioblastoma?

Hemangioblastoma is a benign, non-aggressive tumour in small blood vessels of various brain structures. It accounts for 1-2% of all brain tumours.

Mainly, we find malformations in the cerebellum (the walnut resembling ‘little brain’ tucked in at the back), but they are also present in the brain stem or spinal cord.
It’s important to note here that many cancers with the suffix –blastoma refer to aggressive cancer, like glioblastoma, another brain tumour. So don’t be confused by this – hemangioblastoma is not usually malignant. However, it can cause various symptoms when it gets larger and pushes on surrounding parts of the cerebellum, brain stem or spinal cord.

Why and when does hemangioblastoma emerge?

The bulk of cases is considered ‘sporadic’ tumours, which are single tumours usually present between the ages of 50 and 60.

The exact cause remains unclear to us, but genetically we associate it with a dysfunctional ‘VHL gene’. Hemangioblastoma is strongly connected to the rare inherited disease, Von Hippel Lindau syndrome (VHL). VHL patients represent less than a quarter of cases and are usually younger. We also know that VHL has a poorer prognosis as it often presents with multiple tumours, possibly in the retina or other organs like a kidney or the liver.

What symptoms do we expect to see?

80% of patients experience the following symptoms, usually associated with cerebellar or brain stem tumours:

• Ataxia- as the cerebellum governs our coordination, many patients present with symptoms of slurred speech, stumbling and haphazard movements, or an unsteady gait
• Headaches
• Nausea and vomiting (this is rooted in the brain stem’s ‘vomiting centre’ – the area postrema)
• Diplopia (double vision)
• Fluctuations in mood

• Whereas between 30% and 79% of patients experience the following, often linked to spinal presentations:
• Dysesthesia (nerve pain associated with damaged nerves)
• Neurogenic bladder (loss of bladder control)
• Trigeminal neuralgia (severe facial pain due to compression of trigeminal nerve)
• Limb muscle weakness

Check out our article on pain syndromes!

Significantly, up to 50% of patients suffer hydrocephalus and intracranial pressure due to a build of cerebrospinal fluid in the brain. This can be life-threatening.

Check out our article on hydrocephalus!

How do we make a diagnosis?

We diagnose hemangioblastoma through CT or MRI imaging of the brain or spinal cord – revealing the tumour’s size and location. This is helpful as some patients do not experience any symptoms. Moreover, we may give patients an angiogram – which is an x-ray to help highlight the feeding arteries or the draining veins of the malformation – tumours love blood!

How do we treat hemangioblastoma?

We favour surgery to remove hemangioblastoma. We call this a tumour resection. In most instances, this stops any tumour from returning. However, the tumour may grow in a particularly tricky place for the surgeon to access, so there’s more risk of neurological deficit. In such cases, we can use radiotherapy to reduce the size of the tumour or slow down growth.

Radiotherapy uses radiation to target the tumour’s DNA to stop the cells from reproducing. While radiation is less invasive than surgery, it is a much slower process. Nonetheless, a newer, more efficient type of treatment we have is stereotactic radiotherapy (SRT). This works similarly to conventional radiotherapy but can treat brain tumours in a single session.

Key takeaway messages

• Hemangioblastoma are rare, benign tumours that can grow inside the brain, on the spinal cord (or other organs among VHL patients)
• They can be negligible and not present with symptoms
• Yet they can grow and push on structures of the brain to cause a variety of symptoms like headaches, nausea, and poor coordination
• Some patients can develop life-threatening hydrocephalus
• Primary treatment is the surgical removal of the tumour, but sometimes surgery is not the best option – we then look to radiotherapy

References

https://www.nhs.uk/conditions/benign-brain-tumour/
https://en.wikipedia.org/wiki/Hemangioblastoma
https://rarediseases.info.nih.gov/diseases/8232/hemangioblastoma
https://radiopaedia.org/articles/haemangioblastoma-central-nervous-system-2?lang=gb
https://neurosurgery.med.uky.edu/neurosurgery-hemangioblastomas