Brain - It is a spongy bunch of tissue, and is sheltered by the skull with 3 thin membranes that is called the meninges. The diluted fluid that is known as the cerebrospinal fluid protects the brain. The fluids will flow throughout the spaces in between the meninges and to spaces within brains that is known to be the ventricles.

Cancer - it started with cells, which is the main component that builds up tissues. The tissues that is responsible for building up the organs of the body.

Normally, cells will grow and divides to form another new cell as long as the body needs the cells. As cells are growing old, the cells die, and it will be replaced by the new cells.
Occasionally, this systematic procedure goes wrong. New cells are keeps on forming even the body does not need them or old cells wound not die even if they should. These extra cells will then form into masses of tissues that are called the tumor.

Benign brain tumors

These are tumors that do not have cancer cells. Benign brain tumor can usually be removed and also hardly ever to grow back. The borders and edges of benign brain tumors are clearly seen, and cells from benign tumors are not invading the tissues that are surrounding them. But, benign tumors could press with the sensitive portion of the brain that may cause a severe health problem. Nothing like benign tumors in the other parts of the body, benign tumors in the brain are often times life threatening. It is seldom turns to a malignant tumor.

Malignant brain tumors

It is a tumor that contains cancer cells. It is generally more severe and more often life threatening. It grows speedily and invades the nearby healthy brain tissues. Cancer cells seldom breaks away with the malignant tumors and spread up from one part to another parts of the brain or even to the body. The spreading is called the metastasis. Other times, the malignant tumors do not go beyond the healthy tissues. Tumor might be contained in a layer of tissues or bones of the skull. It is called the encapsulated tumor.

Tumor Grade

Brain tumors are grouped by grades, ranging from grade l to grade lV. These grades referred to the looks of the cells under the microscope. Cells that are of higher grades look more irregular and it grows faster compared to the cells that are of lower grade tumors.

Primary brain tumors - these are tumors that begin within the brain tissues. They are named from the type of the cells or portion of brain from where they begin.

Secondary brain tumors - once the cancer had spread up from the original part to the other position in the body.