TITLE:
Anaplastic Pleomorphic Xanthoastrocytoma: Morphological and Molecular Features of Three Cases
AUTHORS:
Nil Çomunoğlu, Pınar Karabağlı, Şebnem Batur, Büge Öz
KEYWORDS:
Anaplastic Pleomorphic Xanthoastrocytoma, Fluorescence in Situ Hybridization, Immunohistochemistry
JOURNAL NAME:
Open Journal of Pathology,
Vol.5 No.4,
October
16,
2015
ABSTRACT: Pleomorphic xanthoastrocytoma (PXA) is
usually a low grade astrocytic tumor. However, some cases show significant
mitotic activity (5 or more mitosis per 10 High Power Field) and/or necrosis.
These tumors are described as pleomorphic xanthoastrocytomas with anaplastic
features and display increased risk of recurrence. We aimed to evaluate histopathological,
immunohistochemical and molecular features of PXAs with anaplastic features, by
reporting three primary cases displaying recurrence. Histopathologically we
observed rhabdoid-like monomorphic atypical tumoral cells with increased
mitotic activity, vascular endothelial proliferation and necrosis.
Immunohistochemically, astrocytic and neuronal components displayed different
specific staining properties. In 2 cases p53 was immunopositive. We detected
BRAF V600E mutation in 2 cases and p16 mutation in one case, by fluorescence in
situ hybridization (FISH) method. Anaplastic pleomorphic xanthoastrocytoma
(APXA) is a rare tumor. We have presented 3 primary APXA cases displaying all
characteristic histopathological features. Two of these cases were immunopositive
for p53. Therefore, we think that this marker may not be so useful in
differentiating APXA from glioblastoma (GBM). Two of our three cases display
BRAF V600E mutation, which is compatible with the literature.