Pineal region tumours are cancers of the pineal gland in the brain, or the tissues surrounding it. The pineal gland is a small, pea-shaped organ in the centre of the brain that is responsible for the production and secretion of melatonin (which is more commonly known as the sleep hormonea chemical substance produced by glands in the endocrine system that regulates various functions in the body) in dark settings. Its primary functions are to regulate your 24-hour internal body clock (or circadian rhythm), as well as assisting with the initiation and maintenance of sleep.
The development of a pineal region tumoura tissue mass that forms from groups of unhealthy cells can result in blockages of 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 the spinal cord.
Pineal region tumours are more common in males, and tend to occur more in children and young adults. However, anyone can develop this disease.
Types of Pineal Region Tumours
There are three main types of pineal region tumours, which are classified by the types of cellsthe basic structural and functional unit of all living things the cancera disease where abnormal cells split without control and spread to other nearby body tissue and/or organs originates from.
Germ Cell Tumours
Germ cell tumours (GCTs) are cancers that develop from germ cellsa cell that develops into reproductive cells (eggs in females, sperm in males). In most cases, GCTs in the pineal gland region are germinomas. However, they can also develop as nongerminomatous GCTs, which include:
- Embryonal carcinomas.
- Choriocarcinomas.
- Teratomas.
- Endodermal sinus tumours (also known as yolk sac tumours).
- Mixed tumours (tumours with features of different GCTs).
Gliomas
Gliomas are a type of brain tumour that start in the glial cells of the CNS. Glial cells (or glia) provide structural and physiological support to neurons in the CNS. There are three types of glial cells:
- Astrocytes – tumours that start from astrocytes are called astrocytomas or glioblastomas.
- Oligodendrocytes – tumours that start from oligodendrocytes are called oligodendrogliomas.
- Ependymal cells – tumours that start from ependymal cells are called ependymomas.
Gliomas may occur in or around the pineal gland.
Pineal Gland Tumours
Pineal gland tumours originate from pinealocytes (also known as parenchymal cells), which are the main cells of the pineal gland. These cells responsible for the production and secretion of melatonin in the body. There are four primary types of pineal gland tumours.
Pineocytomas
Pineocytomas are very rare tumours that are often classified as gradea description of how abnormal cancer cells and tissue look under a microscope when compared to healthy cells I (unlikely to metastasise). Unlike most pineal region tumours, pineocytomas are most commonly diagnosed in women and adults between the ages of 30-60 years old. These tumours are usually slow-growing and non-aggressive. The prognosisto predict how a disease/condition may progress and what the outcome might be for pineocytomas is often excellent.
Pineal Parenchymal Tumours of Intermediate Differentiation
Pineal parenchymal tumours of intermediate differentiation are very rare tumours that are often classified as grade II or grade III. This type of tumour has features of both pineocytomas and pineoblastomas. They are more common in women, and people between the ages of 20-70. While these tumours can be aggressive, they can have a good prognosis when caught early.
Papillary Tumours of the Pineal Region
Papillary tumours of the pineal region are very rare tumours that are often classified as grade II or grade III. In some cases, papillary tumours in the pineal region are indistinguishable from pineocytomas or normal pinealocytes. The ages that this tumour is often found ranges from 15 months to 67 years, and there have been few cases of this disease reported. In some cases, this cancer is likely to recur and can be aggressive.
Pineoblastomas
Pineoblastomas are rare and aggressive tumours that are usually classified as grade IV (likely to metastasise). They are the most common type of pineal gland tumour, and mostly affect children under the age of two. Pineoblastomas are extremely aggressive, and may not carry as good of a prognosis as other pineal region tumours.
Treatment
If a pineal region tumour is detected, it will be graded based on size, metastasiswhen the cancer has spread to other parts of the body, also known as mets, and how the cancer cells look under the microscope. Unlike most cancers, cancers in the brain are not staged, only graded. Grading helps your doctors determine the best treatment for you.
Brain cancers are often given a grade from I to IV:
- Grade I (low grade): cells look mostly normal. They are slow growing and rarely recur after treatment.
- Grade II (low grade): cells look slightly abnormal. They are usually slow growing and may recur after treatment.
- Grade III (high grade): cells look more abnormal. They may be fast growing and may have already metastasised.
- Grade IV (high grade): cells look very abnormal. They are usually fast growing and have already metastasised. May have high recurrenceto occur or happen again rate.
Once your tumour has been graded, your doctor may recommend genetic testinga procedure that analyses DNA to identify changes in genes, chromosomes and proteins, which can be used to analyse tumour DNA to help determine which treatment has the greatest chance of success, 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 a variety of factors, including grade, type, patient age and location of the tumour. Treatment options for pineal region tumours may include:
- Chemotherapya cancer treatment that uses drugs to kill or slow the growth of cancer cells, while minimising damage to healthy cells.
- Radiation therapya treatment that uses controlled doses of radiation to damage or kill cancer cells.
- Surgerytreatment involving removal of cancerous tissue and/or tumours and a margin of healthy tissue around it to reduce recurrence, potentially including:
- Shunt insertiona procedure to relieve build-up of cerebrospinal fluid (CSF) in the brain.
- Resectionsurgical removal of tissue or part/all of an organ to remove as much as the tumour as possible (may not be able to resect it all due to its location within the brain).
- Clinical trialsresearch studies performed to test new treatments, tests or procedures and evaluate their effectiveness on various diseases.
- Palliative carea variety of practices and exercises used to provide pain relief and improve quality of life without curing the disease.
Risk factors
Because of how rare pineal region tumours are, there has been limited research done into the riskthe possibility that something bad will happen factors of this disease.
Symptoms
The symptoms of a pineal region tumour may include:
- Hydrocephalusa build up of cerebrospinal fluid (CSF) in the brain, causing pressure and potentially damaging brain tissue, which carries its own set of symptoms:
- Headaches.
- Nauseato feel sick or likely to vomit and/or vomiting.
- Difficulties with eye movement.
- Difficulties with balance.
- Difficulties with walking.
- Fatiguea state of extreme tiredness or exhaustion, can be physical or mental.
- Memory problems.
- Seizures.
Not everyone with the symptoms above will have cancer but see your general practitioner (GP) if you are concerned.
Some of the information regarding symptoms was obtained from the Pineal Region Tumors: Diagnosis and Treatment page published by the National Cancer Insitute.
Diagnosis
If your doctor suspects you have an pineal region tumour, they may order the following tests to confirm the diagnosisthe process of identifying a disease based on signs and symptoms, patient history and medical test results and refer you to a specialist for treatment:
- Neurological examinationan assessment of sensory and motor functions, such as vision, balance and coordination.
- Imagingtests that create detailed images of areas inside the body tests, potentially including:
- CT (computed tomography) scana type of medical imaging that uses x-rays and computer technology to create detailed images of the body.
- MRI (magnetic resonance imaging)a type of medical imaging that uses radiowaves, a strong magnet and computer technology to create detailed images of the body.
- Blood teststesting done to measure the levels of certain substances in the blood.
- Lumbar puncturea procedure that involves inserting a needle between two vertebrae in the lower spine and extracting a sample of cerebrospinal fluid (CSF) for analysis.
- Biopsyremoval of a section of tissue to analyse for cancer cells.
