Diffuse astrocytoma, MYB- or MYBL-altered

Diffuse astrocytoma, MYB- or MYBL-altered
Diagnosis in short
LM DDx	Angiocentric glioma
IHC	GFAP +ve
Gross	soft, unencapsulated
Site	brain - usu. temporal
Prevalence	common - esp. in children
Prognosis	good (WHO Grade I)

Diffuse astrocytoma, MYB- or MYBL-altered is a low-grade, often pediatric-onset astrocytoma. It is very rare.

General

• CNS WHO grade 1.
• Rare epilepsy-associated tumor.
• No sex predilection.

Imaging

• T1 hypointense.
• Non-enhancing.
• Occasionally large cysts.

Gross

• Soft, unencapsulated.
• Grey to white.

Microscopic

Features:

• Diffusely growing.
• Minimal incereased cell density.
• Monomorphic, bland glial cells.

Notes:

• +/-Microvascular proliferation.
• +/-Focal necrosis.
  • Necrosis with pseudopalisading more likely glioblastoma.
• +/-Mitoses - not significant in the context of the Dx.

DDx

• Normal white matter
• Angiocentric glioma

IHC

Features:

• GFAP +ve (fibres).

Prognosis

• Excellent (

See also

• Neuropathology tumours.
• Astrocytoma.