Pineal Cysts
Date issued: June 2024
Review date: June 2026
Ref: A-196/Neurosciences/LD/Pineal cysts v3
PDF: Pineal Cysts.pdf [pdf] 267KB
Pineal Gland
The pineal gland is a small, pea sized organ in the brain shaped like the seed of a pine cone. It is mainly responsible for making melatonin, a hormone which regulates waking and sleeping patterns. The pineal gland is larger in children shrinking with the onset of puberty.
Where is it?
It is located near the centre of the brain between the two hemispheres.
What are Pineal Cysts?
A pineal cyst is a fluid filled sack in the region of the pineal gland.
Pineal cysts are usually completely benign. Rarely are they associated with underlying tumours, but this is likely to be apparent from the initial scan. The causes of these cystic masses are not known. They may be developmental in origin, or they may arise when the pineal gland begins the normal process of shrinkage during puberty.
Signs and Symptoms of a Pineal Cyst
Most pineal cysts are an incidental finding. This means that the cyst is unlikely to be causing any symptoms and the cyst is unrelated to what your brain scan was requested for. Pineal cysts are found in 1- 4% of people undergoing imaging of the brain for other causes.
Although it is rare, occasionally pineal cysts can cause headaches, hydrocephalus or difficulty looking upwards.
Will my cyst grow?
Most people will never experience cyst enlargement and therefore will continue without symptoms.
Although a true pineal cyst is benign and usually harmless your doctor may wish to complete several scans at various intervals to monitor for signs of cyst enlargement and to be certain of your diagnosis.
Once there is a certain diagnosis of a pineal cyst your doctor may continue to recommend periodic scans, others will advocate getting further scans only with the onset of symptoms.
Signs and Symptoms of Cyst Enlargement
It is rare for pineal cysts to get bigger or to cause symptoms. However, when this does occur, problems can arise because there has either been a blockage in the fluid pathways in the brain or there has been bleeding into the cyst. This can result in a backlog of that fluid within the fluid pathways resulting in the development of hydrocephalus.
What is hydrocephalus?
Hydrocephalus is a build-up of cerebrospinal fluid (CSF) in the brain.
Cerebrospinal fluid (CSF) is a colourless fluid that bathes the brain and spine aiming to protect these structures and act as a shock absorber. We produce about a pint (500mls) a day in the ventricles of our brains. It then flows around the brain and spine between the brain’s membranes, and is then reabsorbed into the bloodstream.
The build-up of the CSF leads to increased pressure in the brain which can cause damage to the brain tissue.
Signs and Symptoms of Hydrocephalus
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Irritability or restlessness
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Signs of confusion
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Persisting headache sometimes referred to as crescendo headaches getting progressively worse, which may be worse on waking
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Problems with vision (for example, blurred or double vision)
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Nausea (feeling sick) and vomiting with associated apathy
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Reduced level of consciousness
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Seizures
Left untreated, hydrocephalus can lead to unconsciousness and death and therefore, prompt medical attention should be sought.
DO NOT IGNORE THESE SYMPTOMS THEY MUST BE INVESTIGATED
How might symptomatic pineal cysts be treated?
Surgery is usually recommended for those people with pineal cysts who have hydrocephalus, worsening neurological symptoms or enlargement of the cyst over time. Surgery may include removing the cyst, either as an open surgical procedure (craniotomy) or a less invasive endoscopic procedure.
Occasionally the placement of a ventricular peritoneal shunt or an endoscopic third ventriculostomy may be required to maintain the flow of cerebral spinal fluid as part of the surgical procedure. If this is required, your Consultant and/or specialist nurse will discuss this with you in more detail.
