One way to classify brain tumors is to assess their location in proximity to the tentorium cerebelli, a thick membrane separating the back of the brain from the cerebellum. Supratentorial tumors are found above the tentorium cerebelli, and most are found in adults. They include glioblastomas, meningiomas and schwannomas. Infratentorial tumors, found below the tentorium cerebelli in the cerebellum or in the brain stem, are found in children. These include astrocytomas, medulloblastomas and ependymomas.
Glioblastoma Multiforme
This is the most common primary brain tumor, that is, a tumor that originates in the brain. It is also the most malignant. W. K. Yung, M.D., chair of the Department of Neuro-Oncology at the University of Texas, writes in "MD Anderson Manual of Medical Oncology," that there are two to three cases per 100,000 every year. Most people affected by this disease are at least 50 years old, with a short history of headaches, hemiparalysis and seizures. Despite all of the research that has been conducted, the survival rate of this disease has not increased. The average life expectancy is only nine to 14 months.
Meningioma
Approximately 29 percent of all of primary brain tumors are meningiomas. Many times, these tumors do not cause any symptoms, though headaches, personality changes and seizures are possible. Meningiomas can also cause the overlying skull bone to increase in thickness.
Vestibular Schwannoma
Ramzi Cotran, M.D. explains in "Robbins Pathologic Basis of Disease," that vestibular schwannoma is a common brain tumor, also referred to as an acoustic neuroma. It develops in the inner ear and as it grows, it will press on the cerebellum and brain stem. Symptoms include headaches, earaches, dizziness and, at times, loss of balance. You may also feel pressure in your ear and will slowly develop hearing loss in the ear that has the tumor.
Astrocytoma
According to "The Merck Manual for Healthcare Professionals," astrocytoma is the most common brain tumor found in children. Usually located in the cerebellum, most children with astrocytomas are 5- to 9-years-old. Children will have headaches, nausea and vomiting, weakness and unsteadiness in walking. If the tumor is in the spinal cord, it will be painful and interfere with walking. If the astrocytoma interferes with the nerve pathway that sends information about vision, the child can have vision loss (Brain Tumors in Children. http://www.merck.com/mmpe/sec19/ch285/ch285b.html).
Medulloblastoma
This is the second most common brain tumor of children and the most common malignant tumor located in the cerebellum. Most children who have this type of tumor are between 5 to 7 years old. Highly malignant, medulloblastoma can interfere with the flow of cerebral spinal fluid. If this happens, the fluid can accumulate so much that the brain will swell; this is referred to as hydrocephalus. Children with medulloblastomas usually have headaches, nausea and vomiting, double vision and unsteadiness when they walk (Brain Tumors in Children. http://www.merck.com/mmpe/sec19/ch285/ch285b.html).
Ependymoma
The third most common brain tumor in children, the average age for a child with an ependymoma is 6 years old. This tumor has a tendency to spread to their brain stem. But instead, like medulloblastoma, it will usually interfere with the flow of cerebral spinal fluid and cause hydrocephalus.
References
- "MD Anderson Manual of Medical Oncology"; Hagop Kantarjian, M.D., Robert Wolff, M.D., Charles Koller, M.D.; 2006
- "Robbins Pathologic Basis of Disease"; Ramzi Cotran, M.D., Vinay Kumar, M.D., Stanley Robbins, M.D.; 1994
- The Merck Manual: Brain Tumors in Children
