A brain tumor or intracranial neoplasm occurs when abnormal cells form within the brain. There are two main types of tumors: malignant or cancerous tumors and benign tumors.Cancerous tumors can be divided into primary tumors that start within the brain, and secondary tumors that have spread from somewhere else, known as brain metastasis tumors. This article deals mainly with tumors that start within the brain. All types of brain tumors may produce symptoms that vary depending on the part of the brain involved
Symptoms as consequences of increased intracranial pressure (often first noticed) Large tumors or tumors with extensive peritumoral swelling (edema) inevitably lead to elevated intracranial pressure which translates clinically into headaches, vomiting (with or without nausea), altered state of consciousness (somnolence, coma), dilation of the pupil on the side of the lesion (anisocoria), papilledema (prominent optic disc at the funduscopic eye examination). However, even small tumors obstructing the passage of cerebrospinal fluid (CSF) can also present such symptoms. Increased intracranial pressure may result in brain herniation (i.e. displacement) of certain parts of the brain, such as the cerebellar tonsils or the temporal uncus, resulting in lethal brainstem compression. In very young children, elevated intracranial pressure may cause an increase in the diameter of the skull and bulging of the fontanelles.
New techniques for imaging scans are being researched. These may help doctors better track how well treatment is working and watch for possible tumor recurrence or growth.Researchers are examining biomarkers to find better ways of using blood or other tests to determine the presence of a brain tumor before symptoms begin. Immunotherapy, also called biological response modifier (BRM) therapy, is designed to boost the body's natural defenses to fight the cancer. It uses materials either made by the body or in a laboratory to improve, target, or restore immune system function. Different methods are being studied for brain tumors, such as the use of dendritic cells or the use of vaccines aimed against a specific molecule on the surface of the tumor cells. Several methods are currently being tested in clinical trials.
During the period 1995–2003, 54,336 primary CNS tumors of malignant, benign, and uncertain behavior located in the brain, meninges, spinal cord, cranial nerves, other parts of the CNS, and pituitary and pineal glands were registered in England in persons 0–84 years of age, which gives an annual average of just more than 6,000 new cases. The population covered was all individuals between 0 and 84 years of age in England from 1995 through 2003, which equates to 432 million person-years. There were 28,069 male cases (51.7%) and 26,267 female. The overall incidence rate was 9.21 per 100,000 person-years, and the male and female incidence rates were 9.96 and 8.52 per 100,000 person-years, respectively, giving a male-to-female ratio of 1.17:1.