Medulloblastomas are tumors that arise from primitive neural
cells and are almost exclusively found within the Cerebellum
(the balance and coordination center of the Brain located in the
Posterior Cranial Fossa) in children. They account for up to
10 percent of primary Brain tumors and are one of the most common
tumors in the Posterior Fossa. Medulloblastomas account for almost
20% of Central Nervous System tumors in patients under the age
There are similar tumors occurring in adults, although
these are quite rare. Neuropathologists tend to regard
these as "Blue Cell Tumors" (based upon their staining
characteristics when specimens are prepared for viewing under a
microscope) or "Cerebellar Sarcomas".
We have five (5) such patients (See
Figures 2 A & B) in our series with long term follow of from 5 years
(in 2 patients) and over 15 years in two (2) other
Most Medulloblastomas arise in and occupy the Fourth Ventricle.
The result is the development of increased intracranial pressure
consequent to the ensuing Hydrocephalus. Morning (or matutinal)
headaches are a common initial symptom (since
intracranial pressure usually rises to some degree in everyone when
lying flat and sleeping.) These headaches often disappear once
the patient is up and about for a short while. Symptoms such
as listlessness, lethargy, vomiting in the early morning when
headaches are at a maximum level, balance and gait problems, dizziness
and double vision, are quite common for these tumors.
MRI scans are the most helpful neuroimaging study in
identifying a Posterior Cranial Fossa tumor. (See Figures 1 & 2.)
Direct surgical resection and "debulking" of the tumor is
mandatory as the initial step in the management of patients with
Medulloblastomas. As much tumor as possible is removed,
without causing additional neurological injury.
Radiation Therapy is the single most important
adjunct, once the diagnosis of Medulloblastoma has been
established by surgical resection. Radiation Therapy is avoided
for children less than two (2) years of age since the young,
developing Brain tolerates large doses of radiation poorly.
Consideration must be given for this tumor's potential to "seed"
throughout the Cerebrospinal Fluid (CSF) pathway such as within the
Spinal Canal. This may warrant Spinal Axis radiation on a prophylactic
Chemotherapy is a primary adjunctive treatment for
patients two (2) years old and under since radiation is
contraindicated in that age group. Chemotherapy is the third
arm of this comprehensive effort to prolong and maintain a high
quality of life. Radiation therapy and Chemotherapy (with
agents such as CCNU, vincristine and cis-platinum) following soon
after aggressive surgical resection appears to offer significant
improvement in survival rates for this very deadly disease. These
medications are generally considered to be "traditional management"
("standard" forms of chemotherapy.) Currently there are some
unconventional chemotherapeutic alternatives that offer
considerable hope for improved quality and length of survival.
One of our
has utilized these newer medications such as Temodar
(temozolamide), Avastin (bevacizumab, an anti-angiogenesis agent) and
CPT-11, either alone (or more commonly) in combination or with
other drugs, to produce encouraging results. Additional information
regarding these treatments is available at the
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This page last edited on 2/19