Brain tumour is the uncontrollable and abnormal growth of cells in the brain. Brain tumour can affect the person’s daily activity as the central nervous system controls all functions. Central nervous system comprises of brain and spinal column. Central nervous system is responsible for controlling the functions like body movements, thought process and speech ability. Brain consists of four main parts cerebellum, cerebrum, brain stem and meninges. Physical and behavioural changes are experienced in patients based on the location of tumour among these four parts.
The brain tumours are divided into 2 types based on the initiation of the disease.
- Primary brain tumour
Primary brain tumour starts usually in the brain itself. Primary brain tumour is classified into 2 types based on the speed of the growth of cancer cells.
- Low grade tumours – Low grade tumours (grade 1 or 2) grows very slowly. Low grade tumours can convert into high grade tumours based on the severity of the cancer cells.
- High grade tumours – High grade tumours (grade 3 or 4) grows faster when compared to low grade tumours. The faster the growth of the cancer cells, the more the risk of complications.
- Secondary brain tumour
Secondary brain tumours are very common when compared to primary brain tumour. Secondary brain tumour generally grows in other parts of the body and gets transferred to brain. Patients suffering with cancer diseases like breast, colon and lung cancer are more likely to suffer from brain tumour in severe conditions. These cancer cells when released into the blood tend to affect more organs including brain. Secondary brain tumour is more fatal than primary brain tumour. Patients who are suffering from secondary brain tumour face complications due to the presence of tumour in more than one place.
Brain tumours can be categorised into two different categories based on the severity and treatment. Brain tumours can either be benign tumours or malignant tumours. Benign tumours can be referred to as low grade tumours and can be cured easily if diagnosed and treated in the early stages. Malignant tumours can be referred to as high grade tumours as it grows fast. Benign tumours either grow directly into the brain or they spread from other organs into the brain. Malignant tumours can relapse after treatment and thus it is difficult to assure the patients of complete cure.
Brain tumours are broadly classified into 2 categories based on the location of tumours.
- Glioma – Tumour which grows from the glial cells is referred to as glioma. Glial cells are present surrounding the neurons. Glial cells are also called supporting cells in the central nervous system. There are different types of supporting cells present in the central nervous system. The supporting cells in central nervous system include astrocytes, oligodendrocytes and ependymal cells. The glioma in specific supporting cells has specific names.
- Astrocytoma- The tumour present in the astrocytes is called astrocytoma. These astrocytes are generally found in the cerebrum and cerebellum of the brain.Astrocytoma is the most common type of tumour found in the brain. Astrocytoma is categorised into different grades based on the severity and growth of tumour.
- Oligodendroglioma – Oligodendro glioma is found in the oligodendrocytes. Oligodendrocytes are responsible for producing myelin, a protein rich substance surrounding the nerves.
- Mixed glioma – A tumour which is formed from more than one type of glial cells is referred to as mixed glioma.
- Ependymoma – Tumour which is formed in the thin epithelial lining ort passages of brain where cerebrospinal fluid (CSF) is made is called as ependymoma.
- Brain stem glioma – tumour which is formed in the glial cells or supporting cells in the brain stem is called brain stem glioma.
2. Non- Glioma Tumours
The tumour which is formed in the non supporting cells of brain is called non glioma tumours. These tumours are not found in the glial cells or supporting cells. Non glioma tumours directly start from in the brain. Non glioma tumours are classified into 6 main types based on the location in the brain.
- Meningioma – Tumour which starts forming in the meninges of the brain is called meningioma.
- Pineal gland tumour – tumours which are found in the pituitary gland or pineal gland are called pineal gland tumour
- Primary CNS tumour- Tumour which begins in the brain and spread to the eyes is referred to as primary CNS tumour. Primary CNS tumour is a kind of lymphoma.
- Medulloblastoma- Medulloblastoma is common in children. It is formed in the granular cells of the cerebrum and spreads to the central nervous system.
- Carniopharyngioma – It is formed near the base of the brain. Carniopharyngioma is found near the pituitary gland.
- Acoustic schwannoma – it is commonly known as acoustic neuroma and vestibular schwannoma. Acoustic schwannoma is a very rare kind of tumour found in the vestibular nerve which is present in the inner ear.
There are different risk factors which can increase the risk of brain tumour in people.
- Age – Mostly children and older adults are at high risk of brain tumours.
- Gender – Men are at high risk of brain tumour when compared to women.
- Family history – 4-5% of brain tumour is due to hereditary and genetic related factors.
- Infection- patients infected with Epstein- Barr virus and cytomegalovirus are at high risk of brain tumour
- Electromagnetic field – Electromagnetic rays from the gadgets increases the risk of brain tumour
- Head injury – Serious head injuries and seizures increases the risk of brain tumour.
Patients suffering with brain tumour show visible symptoms. These visible symptoms help in early diagnosis.
- Severe headache
- Memory problem
- Change in behaviour and speech
The most common method for diagnosing brain tumour is imaging techniques. Imaging techniques helps in getting a clear image of the tumour size and its location.
Brain tumour patients can be treated and cured if diagnosed in the initial stages. The most common treatments of brain tumour include surgery, chemotherapy and radiation therapy. Surgery is the first treatment done in patients to remove the brain tumour and few of its surrounding tissues.