Glioma

: A brain tumor that begin in a glial, or supportive, cell, in the brain or spinal cord. Malignant gliomas are the most common primary tumors of the central nervous system (the brain and spinal cord). They are often resistant to treatment and carry a poor prognosis (have a dismal outlook). "Glia" is the Greek word for "glue".

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Any neoplasm derived from one of the various types of cells that form the interstitial tissue of the brain, spinal cord, pineal gland, posterior pituitary gland, and retina. [G. glia, glue, + -oma, tumor]

- brainstem g. a g., generally an astrocytoma, arising in the medulla, pons, or midbrain.

- gigantocellular g. SYN: giant cell glioblastoma multiforme.

- mixed g. a g. composed of two or more malignant elements, most frequently astrocytoma and oligodendroglioma.

- nasal g. term for a lesion that is probably not a true neoplasm, but a teratoma consisting of glial tissue with reactive astrocytes, ganglionic neurons, and ependymal cells in small nodules at the dorsum of the nose, often with intracranial connections.

- g. of optic chiasm a slow-growing tumor, usually an astrocytoma, of the optic chiasm in children.

- optic nerve g. a g., generally an astrocytoma, involving the optic nerve or chiasm.

- g. of the spinal cord a glial tumor of the spinal cord, commonly an ependymoma; neoplasms of the spinal cord are relatively rare, but gliomas constitute approximately one-fourth of the total.

- telangiectatic g., g. telangiectodes a g. in which the stroma has numerous, conspicuous, frequently dilated small blood vessel s and capillaries, as well as large, endothelium-rimmed lakes of blood.

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gli·o·ma glī-'ō-mə, glē- n, pl -mas also -ma·ta -mət-ə a tumor arising from glial cells

gli·o·ma·tous -mə-təs adj

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n.

any tumour of non-nervous cells (glia) in the nervous system. The term is sometimes also used for all tumours that arise in the central nervous system, including astrocytoma and glioblastoma. Tumours of low-grade malignancy produce symptoms by pressure on surrounding structures; those of high-grade malignancy may be infiltrative.

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gli·o·ma (gli-oґmə) [gli- + -oma] originally, a tumor composed of tissue representing neuroglia in any of its stages of development; the term has been extended to include all the primary intrinsic neoplasms of the brain and spinal cord, including astrocytomas, ependymomas, medulloblastomas, medulloepitheliomas, and others. Called also neurogliocytoma, neuroglioma, and neurospongioma. gliomatous adj