Difference between revisions of "Diffuse astrocytoma, MYB- or MYBL-altered"

From Libre Pathology
Jump to navigation Jump to search
(Imaging * gross)
(+IHC + MOL)
Line 51: Line 51:
* Minimal incereased cell density.  
* Minimal incereased cell density.  
* Monomorphic, bland glial cells.
* Monomorphic, bland glial cells.
*  
* Entrapped neurons.
 
* Usu. no mitotic activity


Notes:  
Notes:  
*+/-Microvascular proliferation.
*Focally angiocentric pattern may be present.
*+/-Focal necrosis.
**Necrosis with pseudopalisading more likely glioblastoma.
*+/-Mitoses - not significant in the context of the Dx.


DDx  
DDx  
Line 76: Line 73:
==IHC==
==IHC==
Features:
Features:
*GFAP +ve (fibres).
*GFAP +ve.
 
*Olig2 -ve.
*MAP2 -ve.
*CD34 -ve.
*ATRX retained.


==Molecular==
==Molecular==
*  
* Structural variant of MYB or MYBL1 (most common fusion partners: MAML2, MMP16 , PCDGHA1).<ref>{{cite journal |vauthors=Qaddoumi I, Orisme W, Wen J, Santiago T, Gupta K, Dalton JD, Tang B, Haupfear K, Punchihewa C, Easton J, Mulder H, Boggs K, Shao Y, Rusch M, Becksfort J, Gupta P, Wang S, Lee RP, Brat D, Peter Collins V, Dahiya S, George D, Konomos W, Kurian KM, McFadden K, Serafini LN, Nickols H, Perry A, Shurtleff S, Gajjar A, Boop FA, Klimo PD, Mardis ER, Wilson RK, Baker SJ, Zhang J, Wu G, Downing JR, Tatevossian RG, Ellison DW |title=Genetic alterations in uncommon low-grade neuroepithelial tumors: BRAF, FGFR1, and MYB mutations occur at high frequency and align with morphology |journal=Acta Neuropathol |volume=131 |issue=6 |pages=833–45 |date=June 2016 |pmid=26810070 |pmc=4866893 |doi=10.1007/s00401-016-1539-z |url=}}</ref>
* IDH1/2 wildtype.
* H3F3A wildtype.


==Prognosis==
==Prognosis==

Revision as of 07:39, 4 April 2022

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.
  • Entrapped neurons.
  • Usu. no mitotic activity

Notes:

  • Focally angiocentric pattern may be present.

DDx

  • Normal white matter
  • Angiocentric glioma


Images

Smears


Stains

IHC

Features:

  • GFAP +ve.
  • Olig2 -ve.
  • MAP2 -ve.
  • CD34 -ve.
  • ATRX retained.

Molecular

  • Structural variant of MYB or MYBL1 (most common fusion partners: MAML2, MMP16 , PCDGHA1).[1]
  • IDH1/2 wildtype.
  • H3F3A wildtype.

Prognosis

  • Excellent (

See also

References

  1. ↑ "Genetic alterations in uncommon low-grade neuroepithelial tumors: BRAF, FGFR1, and MYB mutations occur at high frequency and align with morphology". Acta Neuropathol 131 (6): 833–45. June 2016. doi:10.1007/s00401-016-1539-z. PMC 4866893. PMID 26810070. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4866893/.
Retrieved from "https://librepathology.org/w/index.php?title=Diffuse_astrocytoma,_MYB-_or_MYBL-altered&oldid=51921"