1332-1333 / 2437
Staging according to Chang
Variable
Tumor dimension
Variable
Tumor dimension
Tumor
classification
Metastasis
classification
T1
<3 cm
M0
No evidence of gross
subarachnoid or hemato.
metastasis
T2
>3cm
M1
Microscopic tumor cell in CSF
T3a
>3 with Tu into the
aqueduct/foramen Luschkae,
cerebral subarachnoid space,
third or lateral ventricles
M2
Gross nodular seeding in
cerebellum
T3b
>3 cm with unequivocal
spread into the brainstem; for
T3b surgical staging may be
used in the absence of
involvement at imaging
M3
Gross nodular seeding in
spinal subarachnoid space
T4
>3cm with spread beyond the
aqueduct of Sylvius and
Foramen magnum
M4
Metastasis beyond
cerebrospinal axis