IDH-mutant astrocytomas with primitive neuronal component have a distinct methylation profile and a higher risk of leptomeningeal spread.

IDH-mutant astrocytomas are diffuse gliomas that are defined by characteristic mutations in IDH1 or IDH2 and do not have complete 1p/19q co-deletion. The established grading criteria include histological features of brisk mitotic activity (grade 3) and necrosis and/or microvascular proliferation (grade 4). In addition, homozygous deletion of the CDKN2A/B locus has recently been implemented as a molecular marker for grade 4 IDH-mutant astrocytomas.

Concurrent RB1 and P53 pathway disruption predisposes to the development of a primitive neuronal component in high-grade gliomas depending on MYC-driven EBF3 transcription.

The foremost feature of glioblastoma (GBM), the most frequent malignant brain tumours in adults, is a remarkable degree of intra- and inter-tumour heterogeneity reflecting the coexistence within the tumour bulk of different cell populations displaying distinctive genetic and transcriptomic profiles. GBM with primitive neuronal component (PNC), recently identified by DNA methylation-based classification as a peculiar GBM subtype (GBM-PNC), is a poorly recognized and aggressive GBM variant characterised by nodules containing cells with primitive neuronal differentiation along with conventional GBM areas. In addition, the presence of a PNC component has been also reported in IDH-mutant high-grade gliomas (HGGs), and to a lesser extent to other HGGs, suggesting that regardless from being IDH-mutant or IDH-wildtype, peculiar genetic and/or epigenetic events may contribute to the phenotypic skewing with the emergence of the PNC phenotype.

Germline testing of Iranian families suspected of Lynch syndrome: molecular characterization and current surveillance of families with pathogenic variants in MSH2, MSH6, and PMS2.

Lynch syndrome accounts for 3-5% of all colorectal and endometrial cancer cases, and suboptimal management of Lynch syndrome in the Middle East resulted in the underdiagnosis of mutation carriers. Probands from 24 unrelated Iranian families with a history of cancer(s) suggestive of Lynch syndrome underwent microsatellite instability analysis or immunohistochemistry, multigene panel testing, copy number variation detection, or multiplex ligation-dependent probe amplification. Pathogenic variants were identified in five patients (21%), including three in MSH2, one in MSH6, and one in PMS2.

The oculomotor cistern and pituitary adenomas: anatomical and clinical study.

Objective: The oculomotor cistern (OMC) is a meningeal cuff filled with CSF that contains the oculomotor nerve (cranial nerve [CN] III) at the level of the lateral wall of the cavernous sinus. Only a few studies have investigated the involvement of the OMC by pituitary adenomas (pituitary neuroendocrine tumors [PitNETs]), mainly with relatively small case series. The aim of this study was to perform a histomorphological description of the OMC and systematically analyze its involvement by PitNETs from radiological, clinical, and surgical perspectives.