Gliomas

Primary brain tumors are cancers that originate in the brain. These tumors are very different from secondary brain tumors, which originally developed elsewhere in the body and spread (metastasized) to the brain.

Primary brain tumors develop from glial cells. Glial cells provide the structural backbone of the brain and support the function of the neurons (nerve cells), which are responsible for thought, sensation, muscle control, and coordination.

CLASSIFICATION OF PRIMARY BRAIN TUMORS

Primary brain tumors are tumors that classified according to their appearance under the microscope. Gliomas are classified into four grades (I,II,III and IV), and the treatment and prognosis depend upon the tumor grade [1].

Grade I or II tumors are termed low-grade gliomas. The term malignant or high-grade glioma refers to tumors that are classified as:

• Grade III (anaplastic astrocytoma, anaplastic oligodendroglioma, anaplastic oligoastrocytoma, anaplastic ependymoma)
• Grade IV (glioblastoma)

HIGH-GRADE GLIOMA SYMPTOMS

Gliomas cause symptoms by invading (growing) into and/or creating pressure in nearby normal brain tissue. The most common symptoms include:

• Headache

• Seizures — Seizures occur in more than one-half of patients with grade III gliomas, and about one-fourth of patients with grade IV gliomas. Seizures are caused by disorganized electrical activity in the brain. Medications can help to control seizures.

Other common symptoms of brain tumors include memory loss, muscle weakness, visual symptoms, difficulty in using or understanding language, and personality changes.

HIGH-GRADE GLIOMA TESTS

Imaging studies — If your healthcare provider is concerned about your symptoms, s/he may recommend a scan of the brain. This can be done using MRI or CT. Both tests provide a very detailed image of the brain. However, a CT or MRI cannot determine for sure if a mass is a cancerous tumor.

Biopsy — The only way to determine the type of tumor with certainty is for a neurosurgeon to remove a piece of the tumor (biopsy), usually during surgery. A pathologist will then examine the biopsy under a microscope.

However, a biopsy may be done without surgery; this approach is preferred if the tumor is located within a critical area of the brain or if you are too sick for surgery. In these circumstances, a procedure called a stereotactic needle biopsy is used to take a sample of the tumor by inserting a needle through the skull into the brain itself.

Source: UpToDate For Patients