[Tumor progression of diffuse median glioma with H3 K27 alteration from pilocytic astrocytoma to glioblastoma].

In the latest revisions of the WHO Classification of CNS Tumors, carried out in 2016 and 2021, the traditional histogenetic classification of gliomas is rebuilt on a new molecular genetic basis, according to which diffuse midline glioma with alteration of histone H3 K27 is distinguished as a specific pediatric oncosyndrome. The rationale was the association of this feature of midline gliomas in children with a worse prognosis and the prospective possibilities of targeted therapy. A thematic review of the literature and our own observation of H3 K27M-positive glioma in the area of the right thalamus in a 6-year-old child, which initially had the appearance of pilocytic astrocytoma, recurred three times (within 1.

[Chordoma as a neurosurgical pathology].

Objective: Assess the significance of chordoma as a neurosurgical pathology, taking into account the latest edition of the WHO classification of soft tissues and bone tumors (2020).

Material And Methods: An analysis of 28 chordomas was carried out. All chordomas were histologically verified, including using immunohistochemical markers of notochordal differentiation (S100, EMA, keratin, brachiuria protein).

[The phenomenon of pseudotumorous cross immunohistochemical reactivity of glia in progressive multifocal leukoencephalopathy].

Progressive multifocal leukoencephalopathy (PML) is a subacute demyelinating brain damage caused by infection of oligodendrocytes and astrocytes with the lytic JC virus on the background of immunosuppression. A case report of PML with a tumor-like course is presented. Morphological diagnostics revealed non-specific staining of antibodies to Ki-67, p53, IDH1, NF and Vim in the nuclei of gliocytes affected by the JC virus.