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pleomorphic xanthoastrocytoma (PXA)
Epidemiology:
- characteristically occurs in children or young adults
- accounts for < 1% of all astrocytic neoplasms
Clinical manifestations:
- seizure
Radiology:
- large well circumscribed mass with cystic and solid components or cyst with mural nodule
Pathology:
1) gross pathology
a) usually more well demarcated
b) tends to be superficially located in cerebral hemispheres
c) temporal lobe most common location
d) may be cystic
2) tumor characteristics:
a) corresponds histologically to WHO grade 2
b) minority progress to anaplastic astrocytoma or glioblastoma.
c) mitotic index & extent of resection appeared to correlate with tumor recurrence & overall survival
d) Ref [1] proposes the term PXA with anaplastic features for > 5 mitoses per 10 high power fields Microscopic pathology
1) pleomorphic cells
2) mono- or multi-nucleated giant cells sometimes containing lipid vacuoles
3) granular bodies, eosinophilic or pale
4) reticulin staining around individual/clusters of tumor cells
5) GFAP varies, often intense
6) nuclear inclusions
7) occasionally Rosenthal fibers
8) mitotic figures &/or necrosis may be present
Immunopathology:
1) GFAP positive most cells
2) beta tubulin
Management:
Prognosis
1) generally favorable prognosis
2) 70% ten year survival rate
General
astrocytoma (astrocytic neoplasm)
References
- Giannini et al. Cancer 85:2033-45, 1999
- Harrison's Online, Chapter 370, McGraw-Hill, 2002
- WHO Classification Tumours of the Nervous System.
Kleihues & Cavenee eds. IARC Press 2000
- Martinez-Diaz et al. Arch Pathol Lab Med 127:1187-91, 2003