Astrocytoma, ependymoma, medulloblastoma, and oligodendrocytoma.

 All of these cancers are members of the glioma group and are named for the type of cells or parts of the brain from which they originate. They generally are not as aggressive as glioblastomas and long-term survival is not uncommon. Astrocytomas account for 10 percent of all primary brain tumors; each of the others accounts for 4 to 5 percent.

Astrocytomas have a relatively low degree of malignancy, although after many years some undergo transformation into a more aggressive form. Astrocytomas often produce movement disorders in children, which often can be cured by total removal of the tumor. Children recover surprisingly well from brain surgery, since another part of the brain seems to compensate for the portion that had to be removed. Most astrocytoma patients are adults who first notice minor vague symptoms that may remain undiagnosed for years. Unexplained headaches, thought disorders, and seizures may occur, but eventually symptoms progress to the point where the cancer becomes more evident. An uncommon site of origin of this cancer is the optic nerve. CT scanning is crucial, especially since the results of all other neurological testing may appear normal in the early stages of the disease.

Astrocytoma is treated by surgery followed by radiation. Chemotherapy is of no benefit. Survival depends on the location of the cancer and its degree of malignancy. Survivals of up to ten years after the onset of symptoms are common, with the average at five to six years. Repeated surgery to remove slowly enlarging tumors has extended survival in some patients.
Oligodendrocytomas are similar to astrocytomas, although seizures are unusual with this soft, slow-growing cancer. Survival averages four to five years. Surgery is the definitive method of both diagnosis and treatment. Transformation into a more malignant grade of cell type can occur with this cancer.

Medulloblastoma commonly occurs in children and only rarely in adults. The tumor is fast-growing, and since it begins in the lower brain near vital structures and cerebrospinal fluid channels, symptoms are evident early in the course of disease. The initial symptoms are apathy, headache, unexplained vomiting; these are soon followed by evident neurologic signs, particularly difficulty in walking. Papilledema a swelling of the optic nerve is easily seen in most children with medulloblastoma. Treatment entails surgery followed by radiation a course that, achieves five-year survival in most patients. Chemotherapy may be a useful adjunctive measure. Shunting procedures to relieve the pressure buildup caused by blockage to the flow of cerebrospinal fluid are often required.

Ependymomas originate in the linings of the ventricles, the spaces in the brain that produce and contain the cerebrospinal fluid. These cancers are most common in children and young adults. The initial symptoms are related to increased intracranial pressure and hydrocephalus. A typical location for ependymoma is the fourth ventricle, one of the narrowest and most easily blocked channels. Surgery is the major treatment. Ependymomas vary in their degree of malignancy, but the average survival after surgery is ten years for low-grade cancers. Postoperative radiation appears to be of some benefit, and shunting procedures relieve intracranial pressure. The tumor can later recur in a more invasive form, but most patients do well for a long period of time.