Histologic diagnosis of pleomorphic xanthoastrocytoma was made because, in addition to the unique pleomorphic histologic features, positive glial fibrillary acidic protein in immunohistochemical staining and characteristic ultrastructural features, i.e., cytoplasmic intermediate fibrils and lipid vacuoles, basal lamina, and abundant reticulin networks were demonstrated.
We report a pleomorphic xanthoastrocytoma with an abnormal clonal cell line of 48,XY, +3, +5, -20, -22, +der(7)t(7;?)(p22;?), +der(20)t(15;20)(q11;q13).
Single-strand conformation polymorphism analysis of p53 exons 5-8 revealed migration shifts in two cases, one primary PXA without recurrence and one recurrent grade II PXA in which the primary tumor did not show a shift.
In the present study, we performed immunostaining for p53 protein and examined the mutation status of exons 5-8 of the p53 gene in 55 PXAs, 8 of which had undergone one or multiple recurrences.
These results suggest that accumulation of MDM2 without gene amplification may be one of the major molecular events occurring in the tumorigenesis of PXA.
Taken together, our study identifies loss of chromosome 9 as the most common chromosomal imbalance in PXAs and suggests important roles for homozygous CDKN2A/p14(ARF)/CDKN2B deletion as well as low TSC1 mRNA expression in these tumors.
Analysis of 10 PXAs with available high molecular weight DNA by high-resolution array-based CGH indicated homozygous 9p21.3 deletions involving the CDKN2A/p14(ARF)/CDKN2B loci in six tumors (60%).
We suggest that the incidence of TP53 mutations in pleomorphic xanthoastrocytoma may be underestimated and that molecular approaches should be used for greater diagnostic precision.
Thus, MGMT promoter methylation is not frequent in PXA and our results raise doubts about the benefits of treating indistinctly aggressive PXA with TMZ.
The expression of MIF and interleukin 8 (IL-8) was evaluated in 36 high-grade gliomas (20 glioblastoma multiforme, 13 anaplastic astrocytoma, and 3 anaplastic oligoastrocytoma) and 32 low-grade gliomas (18 fibrillary astrocytoma, 5 pilocytic astrocytoma, 5 oligodendroglioma, 3 ependymoma and 1 pleomorphic xanthoastrocytoma) by immunostaining.
We evaluated the immunohistochemical (IHC) detection of BRAFV600E mutation in PXA by comparing to gold standard molecular analysis and investigating the interobserver variability of the IHC scoring.
Four adults [2 males; 2 female: median age 45 years (range 34-53)] with surgery, radiation and alkylator refractory recurrent PXA demonstrating the BRAF mutation (V600E) were treated with vemurafenib.
Although this glioma was difficult to clarify, diagnosis of pleomorphic xanthoastrocytoma with anaplastic feature was suggested based on the association of some pathological feature (eosinophilic granular bodies, reticulin network and diffuse CD34 expression) and the BRAFV600E mutation.
Although this glioma was difficult to clarify, diagnosis of pleomorphic xanthoastrocytoma with anaplastic feature was suggested based on the association of some pathological feature (eosinophilic granular bodies, reticulin network and diffuse CD34 expression) and the BRAF V600E mutation.
A valine-to-glutamic acid substitution at position 600 of the serine/threonine-protein kinase BRAF (BRAF V600E) mutation, which is commonly found in PXA, has recently been detected in approximately 50% of all epithelioid glioblastoma (GBM) cases.