|Case 12 :|
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shows infra-tentorial cerebellar mass lesion with CSF metastasis.
with CSF metastasis
tumor usually originates in the cerebellum. It may spread contiguously to
the cerebellar peduncle, floor of the fourth ventricle, into the cervical
spine, or above the tentorium. In addition, it may spread via the
cerebrospinal fluid intracranially and/or to the spinal cord. Every
patient with medulloblastoma should be evaluated with diagnostic imaging
of the entire neuraxis, and when possible, lumbar cerebrospinal fluid
analysis for free- floating tumor cells.
most sensitive method available for evaluating spinal cord subarachnoid
metastasis is spinal magnetic resonance imaging (MRI) performed with
gadolinium. Cerebrospinal fluid shunts at the time of surgery have not
been shown to increase the risk of leptomeningeal relapse.
with disseminated disease at diagnosis are clearly at highest risk for
disease relapse. Other factors that may portend an unfavorable outcome
include younger age at diagnosis, brain stem involvement, subtotal
resection, and a nonposterior fossa tumor. These prognostic variables must
be evaluated in the context of the treatment received.
risk - Children older than 3
years of age with posterior fossa tumors; tumor is totally or
"near-totally" (<1.5 cubic centimeters of residual disease)
resected; no dissemination.
risk - Children younger than 3
years of age or those with metastatic disease and/or subtotal resection
(>1.5 cubic centimeters of residual disease) and/or nonposterior fossa