Q.All are true regarding brainstem glioma except
a. pontine glioma occurs most often between 5 and 6 years of
age
b.pontine glioma is
diffusely infiltrating and tends to run a malignant course
c. In general, midbrain tumours have a tendency to be
indolent and of low-grade astrocytic nature
d. Contrast enhancement of a medullary tumor does not
necessarily mean an aggressive tumor
e. Hydrocephalus is relatively infrequent in midbrain tumour
tumors
337.----e
Hydrocephalus is relatively
infrequent in pontine tumors .In contrast to pontine and medullary tumors,
hydrocephalus is the common presenting finding in patients with midbrain tumors.
On a nonenhanced CT, one third of the pontine tumors are hypodense, one third
are isodense, and one fourth are mixed density, both decreased and isodense.
Only 5% of tumors are of increased density, with the increased density
representing either calcification or blood, and the hemorrhagic focus usually
indicating a malignant zone within the tumor
Masses that are predominately
hyperdense in pons, with or without surrounding focal edema, should be considered
as possible cavernomas . The mass that shows a rim of hemosiderin hypointensity
on T2 or T2* should be thought of as a cavernoma of the brainstem and followed
with imaging.
