Astrocyte - Pathology

Pathology

Astrocytomas are primary intracranial tumors derived from astrocytes cells of the brain. It is also possible that glial progenitors or neural stem cells give rise to astrocytomas.

Astrocytomas are brain tumors that develop from astrocytes. They may occur in many parts of the brain and sometimes in the spinal cord. They can occur at any age but they primarily occur in males. Astrocytomas are divided into two categories: Low grade (I and II) and High Grade (III and IV). Low grade tumors are more common in children and high grade tumors are more common in adults.

Pilocytic Astrocytoma are Grade I tumors. They are considered benign and slow growing tumors. Pilocytic Astrocytomas frequently have cystic portions filled with fluid and a nodule, which is the solid portion. Most are located in the cerebellum. Therefore, most symptoms are related to balance or coordination difficulties. They also occur more frequently in children and teens.

Grade II Tumors grow relatively slow but invade surrounding healthy tissue. Usually considered benign but can grow into malignant tumors. Other names that are used are Fibrillary or Protoplasmic astrocytomas. They are prevalent in younger people who are often present with seizures.

Anaplastic astrocytoma is classified as grade III and are malignant tumors. They grow more rapidly than lower grade tumors and tend to invade nearby healthy tissue. Anaplastic astrocytomas recur more frequently than lower grade tumors because of their tendency to spread into surrounding tissue makes them difficult to completely remove surgically.

Glioblastoma Multiforme is also a malignant tumor and classified as a grade IV. Glioblastomas can contain more than one cell type (i.e., astrocytes, oligondroctyes). Also, while one cell type may die off in response to a particular treatment, the other cell types may continue to multiply. Glioblastomas are the most invasive type of glial tumors. Grows rapidly and spreads to nearby tissue. Approximately 50% of astrocytomas are glioblastomas and are very difficult to treat.