1/15/2008 Case 3: PXA with gangliogliotic differentiation, focal antiomatous areas and hemorrhage

Presented by: Dr. Rao - University Hospital SUNY HSCB

Clinical History:

Case of a 10 year old female with a partially cystic tumor in the frontal lobe, who underwent total resection in Jamaica.  The oncologist requested review of the slides prior to radiotherapy.  Slides showed a pleomorphic astrocytic tumor with vacuolated cells, EGB and obvious neoplastic neurons. 

Diagnostic Notes:

The diagnosis was pleomorphic xanthoastrocytoma with ganglionic differentiation, focal angiomatous areas and focal intratumoral hemorrhage (WHO II).  This is a “PXA-Plus.”  The entity may include composite tumors with elements of DNT, ganglioglioma and ATRT.  PXA may exist as a component of ganglioglioma, or with a glioneuronal malformation.  If a PXA becomes anaplastic, i.e has 5 or more mitoses per 10 HPF) and/or has necrosis, the proper term is “pleomorphic xanthoastrocytoma with anaplastic features” (WHO classification, 2007).

References:        

• Hirato et al.  Expression of non glial intermediate filaments in gliomas.  Clinical Neuropathol 1994;13:1-11.
  
• Powell SZ et al.  Divergent differentiation in pleomorphic xanthoastrocytoma.  Evidence ofr a neuronal element and possible relationship to ganglion cell tumors.  Am J Surg Pathol 1996;20(1):80-85.
  
• Giannini C et al.  Immunophenotype of pleomorphic xanthoastrocytoma.  Am J Surg Pathol 2002;26(4):479-485. 
  
• Hirose et al.  Ultrastructural features of PXA, a comparative study with GBM.  Ultrastructural Pathol 1001;25:469-78.