Brain Tumor Glossary of Terms

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


A benign tumor of epithelium. Warts (caused by papilloma virus) are the most familiar example and each is a clone derived from a single infected cell. The epithelim is the covering of internal and external surfaces of the body, including the lining of vessels and other small cavities. It consists of cells joined by small amounts of cementing substances. Epithelium is classified into types on the basis of the number of layers deep and the shape of the superficial cells.

Parietal lobes

The parietal lobes are found starting above the ear and spanning about three or four inches towards the back of the head on each side of the head. The parietal lobes can be divided into two functional regions. One involves sensation and perception and the other is concerned with integrating sensory input, primarily with the visual system. Individuals with damage to the parietal Damage to the left parietal lobe can result in right-left confusion, difficulty with writing (agraphia) and difficulty with mathematics (acalculia).

Petrous bone

Of, relating to, or constituting the exceptionally hard and dense portion of the human temporal bone that contains the internal auditory (hearing) organs and is a pyramidal process wedged in at the base of the skull between the sphenoid and occipital bones with its lower half exposed on the surface of the skull and pierced by the external auditory meatus (the canal leading from the opening of the external ear to the eardrum).

Positron Emission Tomography (PET)

A procedure in which a small amount of radioactive glucose (sugar) is injected into a vein, and a scanner is used to make detailed, computerized pictures of areas inside the body where the glucose is used. Because cancer cells often use more glucose than normal cells, the pictures can be used to find cancer cells in the body. Also called PET scan.

Prefrontal lobe

The anterior part of the frontal lobe that is made up chiefly of association areas, mediates various inhibitory controls, and is bounded posteriorly by the ascending frontal convolution.

Primary Brain Tumor

The original tumor of a cancer diagnosis. Cancer cells can invade and damage nearby tissues and organs. Also, cancer cells can break away from a malignant tumor and enter the bloodstream or the lymphatic system. This is how cancer spreads from the original (primary) tumor to form new tumors in other parts of the body.

Pseudo tumor

An enlargement that resembles a tumor. It may result from inflammation, accumulation of fluid or other causes, and may or may not regress spontaneously.

Pseudo tumor cerebri

Intracranial pressure, headaches of varying intensity, and papilledema without any demonstrable intracranial lesion and that tends to occur in overweight women from 20 to 50 years of age -- called also benign intracranial hypertension.