Brain Tumor Glossary of Terms

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

Temporal Lobe

The lateral region of the cerebrum, below the lateral fissure. Within The temporal lobe of the brain is the center for smell, some association areas for memory and learning, and a region where choice is made of thoughts to express.


1. Swelling, one of the cardinal signs of inflammation; morbid enlargement. 2. A new growth of tissue in which the multiplication of cells is uncontrolled and progressive. Also called neoplasm.

Tumor calcification

Calcification. The process by which organic tissue becomes hardened by a deposit of calcium salts within its substance.

Tumor Debulking

Surgical removal of as much of a tumor as possible. Tumor debulking may increase the chance that chemotherapy or radiation therapy will kill all the tumor cells. It may also be done to relieve symptoms or help the patient live longer. Also called debulking.

Tumor Infiltrating Lymphocyte

A white blood cell that has left the bloodstream and migrated into a tumor.

Tumor Initiation

A process in which normal cells are changed so that they are able to form tumors. Substances that cause cancer can be tumor initiators.

Tumor Load

Refers to the number of cancer cells, the size of a tumor, or the amount of cancer in the body. Also called tumor burden.

Tumor Lysis Syndrome

A condition that can occur after treatment of a fast-growing cancer, especially certain leukemias and lymphomas (cancers of the blood). As tumor cells die, they break apart and release their contents into the blood. This causes a change in certain chemicals in the blood, which may cause damage to organs, including the kidneys, heart, and liver.

Tumor Marker

A substance that may be found in tumor tissue or released from a tumor into the blood or other body fluids. A high level of a tumor marker may mean that a certain type of cancer is in the body. Examples of tumor markers include CA 125 (in ovarian cancer), CA 15-3 (in breast cancer), CEA (in ovarian, lung, breast, pancreas, and gastrointestinal tract cancers), and PSA (in prostate cancer).

Tumor Microenvironment

The normal cells, molecules, and blood vessels that surround and feed a tumor cell. A tumor can change its microenvironment, and the microenvironment can affect how a tumor grows and spreads.

Tumor Model

Cells, tissues, or animals used to study the development and progression of cancer, and to test new treatments before they are given to humans. Animals with transplanted human tumors or other tissues are called xenograft models.

Tumor Necrosis Factor

A protein made by white blood cells in response to an antigen (substance that causes the immune system to make a specific immune response) or infection. Tumor necrosis factor can also be made in the laboratory. It may boost a person’s immune response, and also may cause necrosis (cell death) of some types of tumor cells. Tumor necrosis factor is being studied in the treatment of some types of cancer. It is a type of cytokine. Also called TNF.

Tumor Promotion

A process in which existing tumors are stimulated to grow. Tumor promoters are not able to cause tumors to form.

Tumor Suppressor Gene

A type of gene that makes a protein called a tumor suppressor protein that helps control cell growth. Mutations (changes in DNA) in tumor suppressor genes may lead to cancer. Also called antioncogene.

Tumor Volume

The size of a cancer measured by the amount of space taken up by the tumor. For example, the tumor volume of prostate cancer is the percentage of the prostate taken up by the tumor.


Taken from an individual's own tumor tissue; may be used in the development of a vaccine that enhances the body's ability to build an immune response to the tumor.

Tumor-specific Antigen

A protein or other molecule that is unique to cancer cells or is much more abundant in them. These molecules are usually found in the plasma (outer) membrane, and they are thought to be potential targets for immunotherapy or other types of anticancer treatment.

Typical brain stem glioma

A brain stem glioma that infiltrates diffusely throughout the pons (the middle portion of the brain stem), sometimes spreading to the midbrain (the upper portion of the brain stem) or he medulla (the bottom portion of the brain stem). The term diffuse intrinsic pontine glioma is synonymous. By pathology, this tumor is most often a fibrillary astrocytoma or its higher grade counterparts (anaplastic astrocytoma and glioblastoma multiforme).