Stepwise to clarify differentiation between pleomorphic xanthoastrocytoma and giant cell glioblastoma using p53, CD34 and KI67; clinicopathological hospital based study.

Background: Giant cell glioblastoma (GCGB) and pleomorphic xanthoastrocytoma (PXA) are rare astrocytic neoplasms. Although they share certain histopathological and histochemical findings, they are characterized by different clinical behaviour and prognosis. Nevertheless, few cases remain uncertain, as their histopathological features and immunophenotypes do not correspond to the typical pattern either of GCGB or PXA and require additional immunohistochemical diagnostic measures for appropriate diagnosis. Specific aims: We carried out this study to address the clinicopathological features of these neoplasms and to examine the expression profile of GFAP, synaptophysin, p53, CD34, and Ki67 proteins. Results: The mean age of the patients was high in GCGB (mean ± SD:49 ± 16.9 years) as compared to PXA (mean ± SD: 29 ± 10.6 years) and APXA (mean ± SD:31 ± 11.5 years). GCGB was more common in women, whereas both PXA and APXA were more common in men. The preferential localization of these tumours was the parietal (GCGB and APXA), and temporal (PXA) lobes. Statistically significant different expressions of P53 (P value = 0.024) and CD34 (P value = 0.001) between PXA and GCGB aid in discrimination between these entities. Interestingly, the similar expression patterns of p53 and CD34 proteins in both GCGB and APXA suggest the presence of possible common molecular mechanisms in both of them. Conclusions: Our work demonstrated that CD34 immunohistochemical expression is more pronounced in PXA, in contrast to p53 which is frequently expressed in GCGB, and APXA. The altered expression of p53, CD34 among GCGB, PXA, and APXA suggests possible roles of these proteins in the development of these neoplasms. [ABSTRACT FROM AUTHOR]