There are more than 120 types of brain and central nervous system (CNS) tumors. Today, most medical institutions use the World Health Organization (WHO) classification system to identify brain tumors. The WHO classifies brain tumors by cell origin and how the cells behave, from the least aggressive (benign) to the most aggressive (malignant). Some tumor types are assigned a grade, ranging from Grade I (least malignant) to Grade IV (most malignant), which signifies the rate of growth. There are variations in grading systems, depending on the tumor type. The classification and grade of an individual tumor help predict its likely behavior. This section describes the most frequently diagnosed types.
Click on the links below for more information on specific tumor types.
- Acoustic Neuroma
- CNS Lymphoma
- Other Gliomas:
- Metastatic Brain Tumors
- Pituitary Tumors
- Primitive Neuroectodermal (PNET)
- Other Brain-Related Conditions
The following tumor types are more common in children than in adults:
- Brain Stem Glioma
- Juvenile Pilocytic Astrocytoma (JPA)
- Optic Nerve Glioma
- Pineal Tumor
- Primitive Neuroectodermal Tumors (PNET)
- Rhabdoid Tumor
Keep in mind that many tumors have different subtypes; for example, an astrocytoma can be a juvenile pilocytic astrocytoma, an anaplastic astrocytoma or a glioblastoma. In addition, the same tumors sometimes have different names; even pathologists are not always consistent in what they call them. Finally, it is important to note that nonmalignant, or benign, brain tumors can be just as difficult to treat as malignant brain tumors.