Brain Tumor Glossary of Terms

Easily explore the meaning of hundreds of medical terms or words, many directly used in brain tumor-related terminology.


Of, relating to, or being the sagittal suture of the skull; or of, relating to, situated in, or being the median plane of the body or any plane parallel to it (a sagáitátal section dividing the body into unequal right and left parts).

Sagittal meningioma

A tumor of meningioma type, of, relating to, or being in area of the sagittal suture of the skull. Also, see meningioma.

Single-Photon Emission Computed Tomography (SPECT)

A special type of computed tomography (CT) scan in which a small amount of a radioactive drug is injected into a vein and a scanner is used to make detailed images of areas inside the body where the radioactive material is taken up by the cells. Single-photon emission computed tomography can give information about blood flow to tissues and chemical reactions (metabolism) in the body. Also called SPECT.

Spinal tap

A procedure in which a thin needle called a spinal needle is put into the lower part of the spinal column to collect cerebrospinal fluid or to give drugs. Also called lumbar puncture.


A malignant tumor of the central nervous system and usually of a cerebral hemisphere -- called also glioblastoma.


Synthetic anti-inflammatory compounds used to reduce the amount of swelling within brain, or other, tissue.

Subarachnoid hemorrhage

Subarachnoid hemorrhage: Bleeding within the head into the space between two membranes that surround the brain. The bleeding is beneath the arachnoid membrane and just above the pia mater. (The arachnoid is the middle of three membranes around the brain while the pia mater is the innermost one.) The subarachnoid space is a potential space. It is normally filled with cerebrospinal fluid. With a subarachnoid bleed, the cerebrospinal fluid in the subarachnoid space is bloody. Subarachnoid hemorrhages are typically acute (sudden). They may follow a head injury or rupture of a blood vessel in the central nervous system (brain and spinal cord) as, for example, because of an aneurysm in the vessel. Nearly half of people admitted to a hospital with a subarachnoid hemorrhage die within a month. Many of the survivors are left with severe disabilities. The first-degree relatives of patients with subarachnoid hemorrhage are more likely to develop the condition than those who do not have a family history of it. Smoking, alcohol abuse, and high blood pressure are risk factors for subarachnoid hemorrhage.


An ependymoma in which there is a diffuse proliferation of subependymal fibrillary astrocytes among the ependymal tumor cells. A few are malignant and others cause obstructive hydrocephalus, but many are clinically silent and are discovered only at autopsy.


Swelling is the enlargement of organs caused by accumulation of excess fluid in tissues, called edema. It can occur throughout the body (generalized), or a specific part or organ can be affected (localized). Swelling is considered one of the five characteristics of inflammation; along with pain, heat, redness, and loss of function. A body part may swell in response to injury, infection, or disease, as well as because of an underlying lump, or tumor in the case of brain disease. Generalized swelling, or massive edema (also called anasarca), is a common sign in severely ill people. Although slight edema may be difficult to detect to the untrained eye, especially in an overweight person, massive edema is very obvious. Brain edema is often treated with steroids, particularly Decadron. A newer drug, Xerecpt, is being tested. Some brain tumor patients use boswellia, a supplement, with some success. Severe brain edema is a serious condition that should be adequately controlled/treated.