Astrocytoma

Astrocytomas are intracranial tumors derived from astrocytes cells of the brain. They can have narrow or diffuse zones of infiltration. more...

Grading

Astrocytomas have great variation in their presentation. WHO acknowledges the following grading system for astrocytomas:

• WHO Grade 1 — pilocytic astrocytoma - accounts for 5% of all reported brain tumors, with a median age at diagnosis of 12 years. This brain tumor is primarily pediatric, although it is also found in adults.
• WHO Grade 2 — diffuse astrocytoma
• WHO Grade 3 — anaplastic (malignant) astrocytoma - accounts for 7% of all primary brain tumors, with the median age at diagnosis of 51 years of age.
• WHO Grade 4 — glioblastoma multiforme (most common) - accounts for 45% of all reported brain tumors, with the median age at diagnosis of 64 years of age.

In addition to these four tumor grades, astrocytomas may combine with oligodendrocytes to produce oligoastrocytoma. Unique astrocytoma variants have also been known to exist.

Symptoms

Although there is variation in initial presentation, in many cases, the first symptom of an astrocytoma is the onset of seizure activity or severe headache. Presentation will vary depending upon the astrocytoma grade, the location of the tumor, among other factors. A Computed Tomography (CT) or Magnetic Resonance Imaging (MRI) scan is necessary to characterize the anatomy of this tumor (size, location, heter/homogeneity). However, final diagnosis of this tumor, like most tumors, relies on histopathologic examination (biopsy examination).

Treatment

A surgeon will typically remove as much of the tumor as he or she can without damaging other critical, healthy brain structures. Often, surgery is followed up by chemotherapy, radiation, or a mix of both. Therapy may be more or less aggressive, depending upon the tumor behavior and patient condition.

Astrocytomas often reappear - the reoccurrence of the tumor are often visible on MRI. The recurrent tumors are then treated similarly as the initial tumor, with sometimes more aggressive chemo or radiation therapy.

There is great life expectancy variation between different subsets of brain tumor. Age and initial diagnosis are often related to survival time.

The prognosis is worst for Grade 4 gliomas, with an average survival time of 14-18 months. Overall, the five year survival rate is 5%.

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