Supratentorial

Question 1

Supratentorial DDx (8)

Answer 1

Adult:
Mets (most common).
Astrocytoma
Gliomatosis cerebri.
Oligodendroglioma.
Primary CNS lymphoma.
Kids:
PXA
DNET
Desmoplastic infantile gangioganglioma/astrocytoma

Question 2

Astrocytoma (8)

Answer 2

Most common primary brain tumour in Adults.
Several types, including
- Pilocytic astrocytoma (WHO 1)
- Diffuse astrocytoma (WHO 2)
- Anaplastic Astrocytoma (WHO 3)
- GBM (WHO 4)
Low grade tumours don’t usually ehnance (WHO 2).
Exception is that Pilocytic astroctoma often has an enhancing nodule.
GBM is the beast that cannot be stopped. Grows rapidly and restricts on diffusion.
Turcot syndrome is associated with GBM.

Question 3

Gliomatosis cerebri (4)

Answer 3

Diffuse glioma with extensive infiltration.
Involves at least 3 lobes, often bilateral.
Usually mild blurring of the grey-white differentiation on CT, with extensive T2 hyperintensity and little mass effect on MRI.
Low grade, doesn’t typically enhance.

Question 4

Primary CNS lymphoma (6)

Answer 4

Seen in end stage AIDS and post transplant.
EB virus plays a role.
Most common in non-hodgkin B cell lymphoma.
Classically: intensely enhancing homogemous solid mass in the periventricular region, with restricted diffusion.
Can look like anything.
Thallium positive on Spect (toxo is not).

Question 5

Desmoplastic infantile ganglioganglioma/astrocytoma (DIG) (5)

Answer 5

Large, cystic tumours that like to involve the superficial cerebral cortex and leptomeninges.
Unlike the atypical teratoma/rhabdoid, usually have OK prognosis.
ALWAYS arise in the supratentoral region, and usually involving more than one lobe (usually frontal and parietal most commonly), usually presents before first birthday.