Pineal region tumours
Pineal region tumours are rare brain tumours. They start in the pineal gland or the tissues around it.
The pineal gland is in the middle of the brain, just behind the brain stem. It makes the hormone melatonin that controls sleep.
Tumours in this part of the brain can block the cerebrospinal fluid channels. The cerebrospinal fluid is a clear fluid that surrounds and protects the brain and the spinal cord.
Blocking the cerebrospinal fluid can cause a build up of fluid in one area of the brain. This can lead to increased pressure (hydrocephalus). Symptoms of increased pressure include headaches and feeling sick.
Types of pineal region tumours
There are many types of tumours that can start in the pineal region. The 2 main types are:
- germ cell tumours
- tumours that start in the pineal gland (pineal gland tumours)
Tumours can also start in the supporting cells (glial cells) in or around the pineal gland. These are called gliomas.
Germ cell tumours grow from cells that are left over from the earliest development of the body in the womb. Normally these cells are harmless, but some can start to grow out of control.
The germ cells in the embryo develop into the reproductive system. So germ cell tumours are also called embryonal tumours.
Most germ cell tumours start outside the brain, in the chest or tummy (abdomen). But they can also start near the pineal gland region. Germ cell tumours mainly affect young people. The risk is greatest in those aged between 10 and 20 years old.
When germ cell tumours start in the brain, doctors call them intracranial germ cell tumours. There are different types including:
- embryonal carcinoma
- yolk sac tumor
- mixed germ cell tumours
There are different types of pineal gland tumours. They can be low grade (slow growing) or high grade (fast growing). There are 5 main types:
- pineocytoma (grade 1)
- pineal parenchymal tumour of intermediate differentiation (grade 2 or grade 3)
- papillary tumour of the pineal region (grade 2 or grade 3)
- pineoblastoma (grade 4)
- desmoplastic myxoid tumor of the pineal region, SMARCB1-mutant
How common it is
Pineal region tumours are rare. Less than 1 in every 100 brain tumours (less than 1%) start in the pineal gland region. They are more common in children and young people than adults.
What tests will I have?
You have tests to diagnose a pineal region tumour. Your doctor checks the size of the tumour and its exact location. This helps your doctor plan your treatment. The test you might have include:
- MRI scan or CT scan
- a biopsy of the tumour
- a test to take a sample of fluid that surrounds the brain and spinal cord (lumbar puncture)
- blood tests
Some germ cell tumours make substances that can show in the blood. These are called tumour markers. If your doctor thinks that you have a germ cell tumour, you might have blood tests to look for:
- alpha fetoprotein (AFP)
- human chorio gonadotropin (HCG)
Treatment for pineal region tumours
Treatment depends on the type of tumour you have.
Treatment for germ cell tumours
For a germ cell tumour, you usually have radiotherapy or a combination of chemotherapy and radiotherapy. For some people, this is the only treatment they need. Other people might have an operation to remove any remaining tumour.
If the germ cell tumour comes back, you might have more chemotherapy and radiotherapy.
Treatment for pineal gland tumours
Treatment depends on the type and grade of pineal gland tumour you have. For a pineocytoma, you usually have surgery to remove as much of the tumour as possible. This might be all the treatment you need. Or, your doctor might recommend that you have radiotherapy after surgery. This is to stop the tumour from coming back.
For high grade tumours, such as pineoblastomas, you might have surgery, radiotherapy and chemotherapy.
Surgery to drain a build up of fluid on your brain (hydrocephalus)
Pineal gland tumours can cause a build up of cerebrospinal fluid on one area of the brain. The excess fluid increases the pressure on the brain which can be serious. This is called hydrocephalus.
You might have surgery to place a shunt if you have this. The shunt is a thin tube that is put in the brain to allow the fluid to flow elsewhere.
You have regular appointments with your doctor or nurse after treatment finishes. Your doctor examines you at each appointment. They ask how you are feeling, whether you have had any symptoms or side effects, and if you are worried about anything. You might have hearing tests. And you might also have MRI scans on some visits.
How often you have check ups depends on your individual situation.
Coping with pineal region tumours
Coping with a diagnosis of a brain tumour can be difficult, both practically and emotionally. It can be especially difficult when you have a rare tumour. Being well informed about the type of tumour you have, and its treatment can make it easier to cope.
Research and clinical trials
Doctors are always trying to improve the diagnosis and treatment of brain tumours. As part of your treatment, your doctor might ask you to take part in a clinical trial. This might be to test a new treatment or look at different combinations of existing treatments.