What is a brain tumor?
Medikoe Health Expert
Koramangala, bengaluru, karnataka, india, Bengaluru Feb 9, 2017
A tumor is a mass of tissue that is formed by an accumulation of abnormal cells. A brain tumor is a growth of abnormal cells in your brain. Tumor cells grow, even when the body does not need them and they don’t die. Brain tumors can be cancerous (malignant) or non-cancerous (benign). When benign or malignant tumors grow, they cause the pressure inside our skull to increase in mass. This can cause brain damage and it can be life-threatening. Brain tumors are divided as primary or secondary. A primary brain tumor originates in the brain. Many primary brain tumors are benign. A secondary brain tumor, also known as a metastatic brain tumor, occur when cancer cells spread to your brain from another organ, such as your lung or breast.
Types of Tumour
The most common type of primary brain tumor among adults are astrocytoma, meningioma, oligodendroglioma.
Astrocytoma: It arises from star-shaped glial cells called astrocytes and it rises in the cerebrum.
Meningioma: The tumor arises in the meninges. It can be grade I, II, or III. It is usually benign (grade I) and grows slowly.
Oligodendroglioma: A tumour arises from cells that make the fatty substance that covers and protects nerves and usually occurs in the cerebrum. It's most common in middle-aged adults. It can be grade II or III.
The most common type of primary brain tumors in children are medulloblastoma, grade I or II astrocytoma, ependymoma, and brain stem glioma.
- Medulloblastoma: The tumor usually arises in the cerebellum and sometimes it is called a primitive neuroectodermal tumor. It is grade IV.
- Grade I or II astrocytoma: In children, it occurs anywhere in the brain. Juvenile pilocytic astrocytoma is most common in children and it is Grade I.
- Ependymoma: The tumor arises from cells that line the ventricles or the central canal of the spinal cord. It's most commonly found in children and young adults. It can be grade I, II, or III.
- Brain stem glioma: It occurs in the lowest part of the brain. It can be a low-grade or a high-grade tumor and the most common type is diffuse intrinsic pontine glioma.
Brain tumor grades
Doctors group brain tumors by grade. The grade of a tumor refers to the way the cells look under a microscope:
- Grade I: The tissue is benign and the cells look nearly like normal brain cells, and they grow slowly.
- Grade II: The tissue is malignant and the cells look less like normal cells than do the cells in a Grade 1 tumor.
- Grade III: The malignant tissue has cells that look very different from normal cells. The abnormal cells are actively growing (anaplastic).
- Grade IV: The malignant tissue has cells that look most abnormal and tend to grow quickly.
The symptoms of a brain tumor depend on tumor size, type, and location. Symptoms may be caused when a tumor presses on a nerve or harms a part of the brain. Symptoms are Headache, nausea, vomiting Changes in speech, vision, or hearing, a problem in walking, changes in mood and personality, Problems with memory, muscle jerking or twitching, numbness in arms and legs, changes in speech, vision or hearing.
Brain Tumour Diagnosis
- Neurologic exam: Doctor Checks vision, hearing, alertness, muscle strength, coordination, and reflexes and also examines eyes to look for swelling caused by the tumor.
- MRI: Some special dye is injected into a blood vessel in arm or hand to help show differences in the tissues of the brain
- CT scan
- Spinal tap: Doctor takes a sample of cerebrospinal fluid (the fluid that fills the spaces in and around the brain and spinal cord) to check cancer fluid cells.
- Biopsy: The removal of tissue to look for tumor cells is called a biopsy