Brain and Spinal Cord Tumors

Introduction

The diagnosis of a brain or spinal cord tumor often comes as a shock, leaving confusion, uncertainty, fear, or even anger in its wake. After the diagnosis, a physician's explanation can fall on ears deafened by this blow. Although it cannot substitute for the advice and expertise of a physician, this brochure is designed to convey the latest research information on the diagnosis, course, and possible treatment of various brain and spinal cord tumors, so that patients and their families have the information they need to become active participants in their treatment.

What Are Brain and Spinal Cord Tumors?

Brain and spinal cord tumors are abnormal growths of tissue found inside the skull or the bony spinal column. The word tumor is used to describe both abnormal growths that are new (neoplasms) and those present at birth (congenital tumors). This brochure will focus primarily on neoplasms.

No matter where they are located in the body, tumors are usually classed as benign (or non-cancerous) if the cells that make up the growth are similar to other normal cells, grow relatively slowly, and are confined to one location. Tumors are called malignant (or cancerous) when the cells are very different from normal cells, grow relatively quickly, and can spread easily to other locations.

In most parts of the body, benign tumors are not particularly harmful. This is not necessarily true in the brain and spinal cord, which are the primary components of the central nervous system (CNS). Because the CNS is housed within rigid, bony quarters (that is, the skull and spinal column), any abnormal growth can place pressure on sensitive tissues and impair function. Also, any tumor located near vital brain structures or sensitive spinal cord nerves can seriously threaten health. If a benign tumor is found deep inside the brain, surgery to remove it may be very risky because of the chances of damaging vital brain centers. On the other hand, a benign tumor located near the brain's surface can often be removed surgically.

An important difference between malignant tumors in the CNS and those elsewhere in the body lies with their potential to spread. While malignant cells elsewhere in the body can easily seed tumors inside the brain and spinal cord, malignant CNS tumors rarely spread out to other body parts. Laboratory and clinical investigators are exploring the basis of these unusual characteristics of CNS tumors, because these unique properties may suggest new strategies to prevent or treat them.

What Causes These Tumors?

When newly formed tumors begin within the brain or spinal cord, they are called primary tumors. Primary CNS tumors rarely grow from neurons - nerve cells that perform the nervous system's important functions - because once neurons are mature they no longer divide and multiply. Instead, most tumors are caused by out-of-control growth among cells that surround and support neurons. Primary CNS tumors - such as gliomas and meningiomas - are named by the types of cells comprising them, their location, or both. The appendix at the end of this brochure describes many types of primary CNS tumors, as well as other tumor-related conditions.