[Astrocytoma with 1p19q codeletion]. / Astrotsitoma s kodeletsiei 1p19q.

Using the example of a recurrent tumor with a 10-year follow-up, the authors show that mutation of the IDH1/2 genes in astrocytomas is not always an early event in the pathogenesis of glioma, that in rare cases a 1p19q codeletion can be found in astrocytomas, and that IDH-mutant tumors can occur in childhood.

[Sarcomas of the central nervous systems. Clinical observations]. / Sarkomy tsentral'noi nervnoi sistemy. Klinicheskie nablyudeniya.

Here we report three patients with rare primary intracranial sarcomas, two of them were CIC-sarcomas and one was a DICER1-sarcoma. Tumors were examined using DNA methylation. It is important to study of CIC fusions and DICER1 mutations in malignant brain tumors.

[Primary sellar neuroblastoma (clinical case and literature review)]. / Pervichnaya sellyarnaya neiroblastoma. Klinicheskoe nablyudenie i obzor literatury.

Neuroblastoma is a malignancy developing from the embryonic neuroblasts of sympathetic nervous system. Primary sellar neuroblastomas are extremely rare (there are currently only 11 case reports in the literature). Possible development of neuroblastoma in sellar region expands differential diagnosis of local processes due to inclusion of neuroblastoma into the spectrum of suspected tumors. We report a literature review and description of a patient with primary sellar neuroblastoma.

[Heterogeneity of tumor cells in glioblastomas]. / Geterogennost' opukholevykh kletok v glioblastomakh.

OBJECTIVE: To comprehensively assess the functional molecular biological status of different tumor cell populations in glioblastoma samples. MATERIAL AND METHODS: The activity of Ki-67, Bcl-2, and BCL6 expression was determined in 20 tumor samples from patients with glioblastoma. After that, a spatial analysis of heterogeneity in the expression of these markers in different tumor cell populations was carried out using computer and software tools and calculating the percentage of cells (PC) expressing this marker (Ki-67 labeling index (LI)) and a modified histoscore in different cell clusters. RESULTS: Analysis of heterogeneity in the distribution of Ki-67, Bcl-2, and BCL6 expression could identify five cell clusters differing in the expression level of the above-mentioned markers. The most active cluster was the perivascular one (the highest mean Ki-67 LI (22.23±1.4%) and histoscore (118.59±3.36%); BCL6 PC and histoscore (17.4±1.4 and 79.32±4.86%, respectively). The least proliferative activity was observed in the perinecrotic cluster (Ki-67 LI (6.83±0.5%) and histoscore (62.46±2.25%)), while the neighboring transient necrotic cluster displayed sufficiently active proliferative processes (Ki-67 LI (18.39±0.56%) and histoscore (112.65±2.76%)). In addition, the transient vascular cluster was noted for a low proliferative activity (Ki-67 LI (8.37±0.35%) and histoscore (75.48±2.04%)). Finally, the intermediate cluster was characterized by the mean values of all parameters (Ki-67 LI (10.68±0.39%) and histoscore (95.73±2.37%). It should be noted that the differences in the expression activity for markers in these clusters were statistically significant. CONCLUSION: The perivascular cluster carries the greatest potential for tumor progression and recurrence, which agrees with the data available in the literature: the perivascular zone is the most important niche for glioma stem cells that make a considerable contribution to the malignant potential of glioblastoma. Tumor pathogenesis and morphogenesis are a complex interweaving of interrelated factors, the realization of which within the framework of a multi-level heterochronic pathological process leads to the segregation of tumor cells and to the appearance of separate cell populations described in this paper.

[Central nervous system atypical teratoid/rhabdoid tumor without loss of nuclear expression of INI1]. / Atipicheskaia teratoidno-rabdoidnaia opukhol' TsNS bez poteri iadernoi ékspressii INI1.

The paper describes a clinical case of atypical teratoid/rhabdoid tumor with preserved INI1 expression and SMARCA4 gene mutations in an 8-month-old girl. Genome-wide DNA methylation, hierarchical clustering, and next-generation sequencing were used to make a tumor diagnosis. However, BRG1 immunohistochemical examination may be recommended in the routine practice of diagnosis and study of childhood CNS malignant tumors.

[Surgical treatment of intramedullary-extramedullary ependymomas. Two clinical cases and a literature review]. / Khirurgicheskoe lechenie intra-ékstramedulliarnykh épendimom. Dva klinicheskikh nabliudeniia i obzor literatury.

Ependymoma is a central nervous system tumor that grows from ependymal cells lining the cerebral ventricles, central canal of the spinal cord, and filum terminale. Regardless of the histological type of ependymomas, they rarely have exophytic growth. Because of an extremely low occurrence rate of this phenomenon, we present two clinical cases of patients with classical intramedullary ependymomas (Grade II) having an extramedullary component. MATERIAL AND METHODS: The paper presents two clinical cases of patients with intramedullary-extramedullary ependymomas of the spinal cord. The surgical technique is described. After surgical treatment, the performance status of patients remained unchanged. CONCLUSION: Radical removal of complex ependymomas provides conditions for long-term disease-free survival and further neurological recovery.

[Basal ganglia germinomas in children. Four clinical cases and a literature review].

UNLABELLED: Basal ganglia germinomas are a specific group of intracranial germinomas. Their early diagnosis is complicated due to their atypical localization and diversity of neuroimaging and clinical signs. MATERIAL AND METHODS: We describe 4 cases of basal ganglia germinoma in boys of 13, 14, 15, and 16 years of age. The medical history data, clinical features, neuroimaging and histological characteristics of basal ganglia germonomas, and preliminary results of the treatment are presented. CONCLUSION: Basal ganglia germinomas are usually verified at the late stage of the disease when patients are detected with extended lesions of the basal ganglia and severe neurological and neuroendocrine deficits. This situation is due to clinical and imaging signs that are untypical of common germinomas.

[Characteristics of medulloblastoma in children under age of three years].

We present a series of 51 medulloblastoma in children under three years, collected in N.N. Burdenko Neurosurgical Institute from 2000 to 2010. 57% of the tumors showed desmoplastic/nodular histology. Performed fluorescence in situ hybridization (FISH) analysis revealed the MYC oncogene amplification in 4%, the MYCN oncogene amplification - in 8%, isochromosome 17q - in 16% of cases. 9q deletion was found in 8% of desmoplastic/ nodular medulloblastomas. Our results showed that desmoplastic/nodular medulloblastoma has a positive predictive value for progression-free survival. Another feature of a biology of medulloblastomas in children younger than three years is the lack of nuclear accumulation of beta-catenin, and 6q deletion. Medulloblastomas with MYCN oncogene amplification often exhibit desmoplastic/nodular histology and a relatively favorable outcome. The most unfavorable prognostic marker is the MYC oncogene amplification, which in our series of 100% combined with the large cell/anaplastic medulloblastoma and isochromosome 17q - such tumors should be included in the "high risk" protocol.

[Are the medulloepithelioma, ependymoblastoma and embryonal tumor with multilayered rosettes the same entity?].

Medulloepithelioma is a rare malignant tumor arising in cerebral hemispheres. Microscopically, medulloepithelioma is characterized by epithelial structures that mimic the embryonic neural tube. Immunohistochemical analysis revealed that tumor cells are immunopositive for LIN28A and fluorescence in situ hybridization showed an amplification of a miRNA cluster at 19q13.42. Presence of these both aberrations suggesting that medulloepithelioma, ependymoblastoma and embryonal tumor with multilayered rosettes are the same entity.

[Multiple echinococcosis of brain, heart and kidneys].

The authors report a rare case of multiple echinococcosis (brain, heart and kidneys). Neuronavigation, intraoperative ultrasound scanning have allowed to plan exact and non-traumatic access to the cysts. Microsurgical technique and intraoperative neurophysiological monitoring provided removal of seven cysts without their rupture from the left parietooccipital and right parietal area with good postoperative functional result. Serologic analysis of antibodies with antigens of echinococci and histological research confirmed the diagnosis of cystic echinococcosis.

[A new entity in WHO classification of tumors of the central nervous system--embryonic tumor with abundant neuropil and true rosettes: case report and review of literature].

Embryonic tumor with abundant neuropil and true rosettes (ETANTR) is a very aggressive rare tumor with unique histologic and molecular features occurring in very young children. At present approximately 80 cases of ETANTR have been documented in the literature since first description in 2000. We report seven patients with ETANTR below 4 years of age who underwent surgical resection in the Burdenko Neurosurgery Institute between 2005 and 2010. Four children have received different modality chemotherapy and radiotherapy and two patients were treated by chemotherapy alone. One child did not receive any adjuvant treatment. All children had local relapses, two of them were operated twice. A 2 year old girl underwent subtotal resection thrice. Histological examination showed that all tumors were composed of true multilayered rosettes admixed with large areas of paucicellular neuropil. By analysis of recurrences we have found that large areas of neuropil and number of true rosettes were lost and tumors acquired a resemblance to central nervous system primitive neuroectodermal tumors. In four cases frozen tumor material was available for array-based comparative genomic hybridization, which discovered trisomy of chromosome 2 and amplification at the 19q13.42 chromosome locus. Fluorescence in situ hybridization revealed amplification at the 19q13.42 chromosome locus in all cases.

[Analysis of sequences from human brain cDNA gene bank which are functionally active in nervous tissue and tumor cells]. / Analiz posledovatel'nostei, poluchennykh iz banka kDNK mozga cheloveka i aktivno funktsioniruiushchikh v nervnykh i opukholevykh kletkakh.

Construction of a human cortex cDNA bank is described as well as the isolation from this bank of pBH71 and pBH3 clones with preferential expression in nervous and in tumor cells. The clones can be included into the third class of cDNA according to Sutcliff's classification. The mRNA corresponding to this cDNA class is considered to play the key role in determination of specificity of nervous tissue. Expression of the pBH71 sequence was revealed in human cortex and in tissues of different genesis (from neuroblastoma to uterus myoma), a 2 kb mRNA which corresponds to one and the same cDNA chain having been found in all tissues under analysis. The nucleotide sequence of cDNA insertion into the pBH71 clone of 447 n.p. was determined, and particular features of cDNA nucleotide composition and possible schemes of its translation were analysed. Weak homology was found between the 3'-end of cDNA insertion of the pBH71 clone and the 3'-end region of human proopiomelanocortine. The cDNA of the pBH3 clone hybridizes with the 0.8 kb mRNA revealed in human cortex and neuroendocrine tumors of different nature. No homology was revealed between the cDNA sequence of the pBH3 clone and any genes deciphered.

[Evaluation of the effectiveness of polychemotherapy of glial tumors of the brain]. / Otsenka éffektivnosti polikhimioterapii glial'nykh opukholei golovnogo mozga.

A total of 85 courses of polychemotherapy were conducted in 23 patients after surgical treatment of malignant glial tumors. The efficacy of the treatment was checked by means of neurological, neuropsychological, and electroencephalographic methods of examination and radionuclide-gamma-tomography. The aggregate of these tests is necessary for detecting early signs of irresponsiveness of the tumor to chemotherapy and changing the treatment schedule.

[Biosynthesis and cellular localization of embryonal prealbumin in human embryonal tissues]. / Izuchenie biosinteza i kletochnoi lokalizatsii embrional'nogo preal'bumina v tkaniakh ploda cheloveka.

Immunofluorescent analysis of chorion sections and various embryonal tissues revealed localization of embryonal prealbumin (EPA) in the mesenchymal cells of the chorion, bones, umbilical cord, skin and in the cytoplasm of the epithelium distal part of the embryonal kidney canals. Synthesis of EPA slow peak in the suspension tissue culture of the chorion, umbilical cord and bones was shown. It is suggested that EPA is a mesenchyme product which is actively synthesized during the period of embryonal development. EPA is resynthesized and localized in the cells of tumors originated from the connective tissue. Cells of the tumors of non-connective origin did not contain EPA, whereas it was detected in the cells of the adjacent connective tissue. The phenomenon of embryonal reversion, probably, takes place not only in the "original" tumor cells but also in the surrounding connective tissues.