Pleomorphic xanthoastrocytomas (PXA) are rare primary brain tumors recognized from the WHO classification of central nervous system (CNS) tumors since 1993 [1], [2]. Previous studies agree on PXA's epidemiology (young adults), preferred location (supratentorial, superficial, often temporal lobes), and morphology (solid-cystic lesions) [2], [3]. Leptomeningeal involvement is a frequent pathological finding, while dural involvement is rare, even though a reactive “dural-tail” magnetic resonance imaging (MRI) sign has been sometimes described. Nevertheless, PXA diagnosis is difficult. Morphologically, this entity is heterogenous (thus the adjective “pleomorphic”), as spindle, polygonal, multinucleated cells can be seen, and lipid-laden xanthomatous astrocytes are frequently visible [4]. The most common molecular alteration are the BRAF p.V600E mutation and the homozygous deletion of CDKN2A/B (60–78% and 60–95%, respectively) [5], but both alterations are non-specific, as they can be found in other glial and neuro-glial primary brain tumor. Mutation of the TERT promoter (pTERT) can also occur and has been associated with unfavorable prognosis [6]. Therefore, a morphological and molecular overlap between PXA and other brain tumor entities, especially with glioblastoma and its epithelioid variant, is frequent. Astroblastomas and gangliogliomas are also common differential diagnoses [7] as well as the recently described high-grade gliomas with pleomorphic and pseudopapillary features [8].

Recently, genome-wide methylation DNA profiling (MP) has been applied to classify CNS tumors. Unsupervised MP analysis allowed to more robustly define tumor entities and improve pathological diagnosis [9]. A distinct DNA methylation profile for PXA was recently reported [10]. However, a sole epigenetic PXA diagnosis is also inadequate, as it encompasses a wide spectrum of histological diagnosis [6].

Therefore, the integration of histological, molecular and MP information is advisable for the final diagnosis of PXA, especially in doubtful cases. MRI is widely performed to characterize brain-space occupying lesions and has a pivotal role in orienting subsequent therapeutic management and patient prognosis.

While MRI findings of PXA have been described in the past, only histology was considered the gold standard technique at that time to assess PXA diagnosis. Hence, the aim of our study was to analyze the pre-operative MRI of PXAs defined by histology and epigenetic profile (mcPXA group), and to compare their imaging features with those of histological mimicking tumors, notably glioblastoma (GBM) defined by epigenetic profile (mcGBM group), and a miscellaneous of epigenetic-defined tumor (mcMimic group).