Anaplastic pleomorphic xanthoastrocytoma versus pleomorphic xanthoastrocytoma: The uncharted entities with significant prognostic implication – Report of two cases

Abstract

Pleomorphic xanthoastrocytoma (PXA), WHO grade II, is a rare entity accounting for <1% of all astrocytic tumors. It affects children and young adults and is commonly found in the temporal lobe. Anaplastic PXA (APXA) has a similar location and clinical manifestation as that of PXA but has a significantly worse prognosis than the latter. WHO 2016 defined PXA as having >5/10 HPF mitosis and with or without necrosis as APXA (grade III). Herein, we present two such cases with unusual locations and ages: (1) APXA inside lateral ventricle, in a 10-year-old female child and (2) PXA in a 39-year adult male. Histologically, both cases revealed a tumor comprised a highly pleomorphic heterogeneous population of cells, eosinophilic granular bodies, and psammoma bodies, however, necrosis and increased mitosis (>5/10 HPF) were appreciated only in the first case. Immunohistochemistry is supported by strongly positive glial fibrillary acidic protein, vimentin, and synaptophysin. This study analyzed all the characteristics of both these entities with their unusual presentations to prevent future misdiagnoses.