Choroid plexus tumours are rare types of cancer that develop in the choroid plexus, a complex network of blood vessels and cells found in the lining of most of the ventricles in the brain. The main function of the choroid plexus is to produce and secrete cerebrospinal fluid (CSF), which provides protection, nourishment, and waste removal in the central nervous system (CNS). The CNS is responsible for all sensory and motor functions in the body, and is composed of the brain and spinal fluid.
Choroid plexus tumours are slightly more common in females, and are most commonly diagnosed in children under the age of two. However, anyone can develop this disease.
Types of Choroid Plexus Tumours
There are three primary types of choroid plexus tumours, which are classified by the type of cells they develop from.
Choroid Plexus Papilloma
Choroid plexus papillomas are the most common type of choroid plexus tumours, and are often benign. They are generally considered low grade tumours (or grade I tumours), as they often develop slowly and rarely metastasise. Choroid plexus papillomas often have a very good prognosis.
Atypical Plexus Papilloma
Atypical plexus papillomas, also known as atypical choroid plexus papillomas, are the least common type of choroid plexus tumour. They are generally considered intermediate grade tumours (or grade II tumours), as they often develop slowly and rarely metastasise, but can behave more aggressively than choroid plexus papillomas. Atypical plexus papillomas generally have a good prognosis, but are likely to recur after treatment.
Choroid Plexus Carcinomas
Choroid plexus carcinomas are a less common type of choroid plexus tumours, and are often malignant (cancerous). They are generally considered high grade tumours (or grade III tumours), as they are often aggressive and likely to metastasise. Choroid plexus carcinomas may not have as good of a prognosis as other types of choroid plexus tumours.
Treatment
When cancers are detected, they are staged and graded based on size, metastasis (whether the cancer has spread to other parts of the body), and how the cancer cells look under the microscope. Staging and grading helps your doctors determine the best treatment for you. However, brain cancers are rarely staged, as they rarely spread to other parts of the body. Instead, they are generally graded from grades I-III.
Choroid plexus tumours are generally graded by subtype:
- Grade 1 (low grade) tumours: cancer cells present as slightly abnormal and are usually slow growing. Includes choroid plexus papillomas.
- Grade II (intermediate grade) tumours: cancer cells present as abnormal and grow faster than grade-I tumours. Includes atypical plexus papillomas.
- Grade III (high grade) tumours: cancer cells present as very abnormal and grow quickly. Includes choroid plexus carcinomas.
Once your tumour has been graded, your doctor may recommend genetic testing, which analyses your tumour DNA and can help determine which treatment has the greatest chance of success. They will then discuss the most appropriate treatment option for you.
Treatment is dependent on several factors, including location, age, stage of disease and overall health.
Treatment options for choroid plexus tumours may include:
- Surgery, potentially including:
- Removal of as much of the tumour as possible.
- Insertion of a stent to drain excess CSF.
- Radiation therapy.
- Chemotherapy.
- Immunotherapy.
- Clinical trials.
- Palliative care.
For more information on the treatment options, please refer to the Rare Cancers Australia treatment options page.
Some of the information regarding treatment was obtained from the Choroid Plexus Tumour: Diagnosis and Treatment page published by the National Cancer Institute.
Risk factors
Because of how rare choroid plexus tumours are, there has been limited research into the risk factors of this disease. However, certain genetic mutations and Li Fraumeni syndrome have been linked to this disease.
Early symptoms
The main symptoms of choroid plexus tumours result from hydrocephalus, a build-up of CSF in the head, and may cause:
- Nausea and/or vomiting (generally worse in the morning).
- Irritability.
- Headaches (often after waking up in the morning).
- Blurred or double vision.
- Seizures.
- Lethargy (lack of energy).
- Fatigue.
- Problems feeding and/or walking.
- Enlarged fontanelles (soft spots on an infant's head between the bony plates of the skull).
- Enlarged head (more common in infants).
Not everyone with the symptoms above will have cancer, but see your general practitioner (GP) if you are concerned.
Diagnosis/diagnosing
If your doctor suspects you have a choroid plexus tumour, they may order the following tests to confirm the diagnosis and refer you to a specialist for treatment.
Physical examination
Your doctor will collect your overall medical history, as well as your current symptoms. Following this, they may examine your body to check for any abnormalities.
Neurological examination
A neurological examination assesses sensory and motor functions, and can generally be done in your GPs office. The doctor may check your vision, hearing, balance, coordination, strength and reflexes, depending on the signs and symptoms you have described. Any problem that is detected in this exam can help determine which portion of the CNS needs further investigation.
Imaging & Blood tests
The doctor will take images of your body using magnetic resonance imaging (MRI), a computed tomography scan (CT scan), x-rays, bone scan and/or positron emission tomography (PET scan), depending on where it is suspected the cancer is. The doctor may also look at other parts of the body and look for signs of metastasis. Additionally, a blood test may be taken to assess your overall health and help guide treatment decisions.
Lumbar Puncture
A lumbar puncture, or spinal tap, involves inserting a needle between two vertebrae in the lower spine and extracting a sample of cerebrospinal fluid (CSF) for analysis. A local anaesthetic or sedative is given prior to the procedure. Your doctor will discuss any risks and possible complications with you prior to the procedure.
Biopsy
Once the location of the cancer has been identified, the doctor will perform a biopsy to remove a section of tissue using a needle. This can be done by a fine needle aspiration (FNA), or a core needle biopsy (CNB).
Prognosis (Certain factors affect the prognosis and treatment options)
While it is not possible to predict the exact course of the disease, your doctor may be able to give you a general idea based on the rate and depth of tumour growth, susceptibility to treatment, age, overall fitness, and medical history. Generally, low-grade choroid plexus tumours have a better prognosis and survival rates. However, if the cancer is advanced and has spread, the prognosis may not be as good, and there may be a higher risk of cancer recurrence. It is very important to discuss your individual circumstances with your doctor to better understand your prognosis.
References
Some references are to overseas websites. There may be references to drugs and clinical trials that are not available here in Australia.