These are tumors that arise from cells called
Astrocytes, which are normally found within the substance
of the Brain and Spinal Cord. Approximately 3% of
Central Nervous System Astrocytomas arise within the Spinal
Cord. Spinal Cord Astrocytomas occur at any age, but are
more common during the early years of life. They are by
far the most common Intramedullary Spinal Cord tumor in
children. They account for 90% of all
Intramedullary Tumors in patients younger than 10 years of age
and 60% of the Intramedullary Tumors in adolescents.
Almost 60% of these tumors are located in the
Cervical and Cervicothoracic Spinal Cord segments. The
Thoracic, Lumbar and Conus Medullaris locations are less
Spinal Cord Astrocytomas represent a mixed group with
respect to their natural history and histology. WE REGARD ALL
OF THESE TUMORS AS BEING "MALIGNANT". Their biological
behaviors range from Low-grade aggressiveness to Highly
Malignant. These tumors include Low-grade Fibrillary and
Pilocytic Astrocytomas, Anaplastic (or High-grade) Astrocytomas,
Glioblastomas, Gangliogliomas, "Mixed Gliomas" and the rare
Oligodendroglioma. Approximately 25% of adult
Astrocytomas are High-grade Malignant Tumors.
The term "GLIOMA" refers to a "family" of tumors, which
arise from cells known as "GLIAL CELLS". This
series of cells comprises the "glue" cells of the
Central Nervous System (CNS), in contradistinction to the
"Neurons", which are the "action" cells of the Brain
and Spinal Cord. Glial cells are the most common cellular
component of the Brain. They are five to ten times more
frequent than the trillion Brain Neurons and make up half the
Central Nervous System (CNS) by volume.
There are three (3) different cell types in this cell
series. The "Astrocyte" was so named, because it
resembles the shape of a star, when looked at under
a microscope. The next most common cell in this series is the
"Ependymal Cell", which lines the cavities of the
Brain (called Ventricles). These are normal chambers
within the Brain, where Cerebrospinal Fluid (CSF) is
manufactured. These cells are also found within the
Central Canal (a small cavity) within the Spinal Cord.
The last cell type is the "Oligodendrgogliocyte" ("Oligo"),
which is the cell within the Brain and Spinal Cord
responsible for making the insulating material (called
Myelin), that surrounds the fibres (Axons) which
transmit electrical impulses within the Brain and Spinal
Each of these cell types is capable of forming a tumor. The
Neurosurgeons of Neurosurgical Consultants regard ALL OF THESE AS
MALIGNANT TUMORS. The degree of malignancy, and therefore,
biological aggressiveness can vary from quite indolent to extremely
aggressive. These tumors are generally categorized
according to their degree of aggressiveness, as judged by a number of
factors. Neuropathologists (specialists trained to examine
these tumors under powerful microscopes), have tended to "grade"
these tumors from 1 to 4, with "4" being the most
aggressive and "1" being the least malignant.
All of these tumors have a tendency to "infiltrate" within the
Brain and/or Spinal Cord by tracking along the fibre pathways that
interconnect every part of the Brain to every other part of the Brain.
Very rarely do these tumors ever spread beyond the Brain or Spinal
Once again, MRI (without and with Gadolinium as a "contrast"
agent) is the primary method to diagnose these tumors, since it affords
diagnostic anatomical details including the position of the tumor
and its relationship to the Spinal Cord.
Surgery is the most effective treatment for most
Intramedullary Spinal Cord Tumors. The role of surgery is
determined primarily by the nature of the interface between the tumor
and the Spinal Cord. Our strong preference favors
Minimally Invasive Microsurgical
Gross Total Removal of a benign tumor, if a clear
demarcation/interface exists between the Tumor and the Spinal
Cord. Surgical removal alone provides long-term tumor
control or cure for Hemangioblastomas, almost all
Ependymomas, and some well-circumscribed
Determination of the resectability of an intramedullary
tumor is best made by direct intraoperative inspection of the
Tumor-Spinal Cord interface.
Tumors that cannot be totally resected, or are recognized to be more
aggressive (such as High-grade Astrocytomas), will require
post-operative Radiation Therapy and possibly
Chemotherapy as well.
Long-term outcome and risk of recurrence depend primarily
on tumor histology, the completeness of the
original resection and responsiveness to Radiation and/or
Long-term follow-up (usually with MRI Scan) is required for
ALL of these cases since RECURRENCE of any of these tumors remains as
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This page last edited on 2/19