Astrocytoma tumors come in a variety of forms, and they are named after their star-shaped cells called astrocytes.  They are the most common type of primary brain tumor.  Astrocytomas are known by many different names, depending on their characteristics.  The terms "astrocytoma" and "glioma" are used interchangeably.

Astrocytomas are categorized as either low-grade or high-grade.  While low-grade astrocytomas account for the majority of astrocytomas in children, high-grade astrocytomas account for the majority of astrocytomas in adults.  About 80% of diagnosed astrocytomas in children are low-grade.

There are several different types of low-grade astrocytomas:

• juvenile pilocytic astrocytoma (JPA)
• fibrillary (diffuse) astrocytoma
• pleomorphic xanthosastroctyoma (PXA)
• diffuse astrocytoma
• desembryoplastic neuroepithelial tumor (DNET)

JPA's typically grow in the cerebellum (the part of the brain that controls balance) and are more common in children than adults.  Their boundaries are sharply defined and so surgery is most often the "cure" for this type of tumor.  JPA's are Grade I tumors.

Fibrillary (or diffuse) astrocytomas must be distinguished between JPA's and are found in the brain stem.  Fibrillary astrocytomas are the most common form of low-grade astrocytoma.  They are slow growing but have tentacles that spread into normal brain tissue.  Therefore total surgical removal is uncommon.  This type of tumor typically grows in the cerebral hemispheres where thought process is controlled.  Fibrillary astrocytomas are Grade II tumors.

PXA's tend to grow superficially in the brain, and so like pilocytic astrocytomas they are generally "cured" with surgery.  PXA tumors are Grade I tumors.

DNET tumors tend to grow in the temporal regions of the brain.  DNET tumors are Grade xx tumors.

The most common types of high-grade astrocytoma are:

• anaplastic astrocytoma (AA)
• glioblastoma multiforme (GBM)

Anaplastic means malignant.  AA and GBM tumors account for about 10% of all pediatric brain and spinal cord tumors.  AA tumors occur sporadically without identifiable cause.  This is a Grade III tumor and has an increased number of cells, abnormal cells and nuclei, increased proliferation of cells and increased growth of blood vessels.  AA tumors have a tendency to infiltrate adjacent brain tissue and spread outside the central nervous system.

GBM tumors are Grade IV astrocytomas and are fatal.  There are very rare cases documented where children with GBM survive beyond five years.  Most children with GBM die within 18 months of diagnosis.  Those that can make it beyond 18 months generally succumb around three years after diagnosis.

Symptoms for astrocytomas generally include headaches, nausea and vomiting, as well as other symptoms depending which part of the brain the tumor is growing.  Like all brain tumors, symptoms will begin gradually and intensify as the tumor grows.

Survival rates for children with low-grade astrocytomas are as high as 90% five years after diagnosis.  Prognosis for children with high-grade astrocytomas is dismal, and in the rare instances where the child does survive they tend to have severely impacted quality of life issues.