There are considerable variations in the reported incidence methotrexate-induced neurotoxicity in children with malignancies. The etiology of acute neurological deficit in pediatric patients with malignancies during polychemotherapy can be diverse: cerebrovascular disease (arterial ischemic stroke, intracranial hemorrhage, venous sinus thrombosis, or their combination), stroke-like migraine attacks after radiation therapy (SMART), posterior reversible encephalopathy syndrome (PRES), thrombotic microangiopathy, toxic leukoencephalopathy (include strokelike leukoencephalopathy). The tactics of a neurologist largely depends on the reasons that caused the neurological deficit. The doctor needs knowledge not only of the clinical picture and the characteristics of the course of the underlying disease, but also of possible complications arising both as a result of the disease itself and due to the therapy being carried out. Timely diagnosis and correct interpretation of emerging neurological events make it possible to determine rational accompanying therapy. The article presents case histories of children with acute lymphoblastic leukemias and acute neurological deficits, with an analysis of their possible causes. 

Relevance. Infectious septic complications caused by polyresistant gram-negative micro-organisms are a pressing issue in the treatment of patients after polychemotherapy (PCT) and hematopoietic stem cell transplantation at the high risk of the fulminant current and high lethality against the background of hematopoesis aplasia. One of the therapeutic strategies of antimicrobial treatment is the systematic use of 0.5 % hydroxymethylquinoxaline dioxide (dioxidine) solution in the complex antibacterial therapy of patients with severe infectious-septic complications. The preparation has a bactericidal type of action, a wide spectrum of antibacterial activity. Experience in adult clinical practice has demonstrated the effectiveness of dioxidine in the treatment of the most severe forms of aerobic and anaerobic infection. Strict dose enforcement and injection technique to avoid the appearance of side effects. Data on the intravenous use of dioxin in children are presented in a limited number of scientific literature.

The aim of the study was to demonstrate the efficacy of systemic use of hydroxymethylquinoxaline dioxide (0.5 % dioxidine solution) in children with infectious complications progressing against the background of aplasia of hematopoiesis caused by multidrug-resistant pathogens Pseudomonas aeruginosa, Klebsiella pneumoniae, Enterobacter cloacae, Stenotrophomonas maltophilia.

Materials and methods. 16 patients with a verified gram-negative infection were prescribed 0.5 % hydroxymethylquinoxaline dioxide solution as part of a combination antimicrobial therapy were included in the retrospective study. The median age of patients was 5 years (6 months – 16 years), 11 (69 %) were boys and 5 (31 %) girls.

All children included in the study has infectious-septic complications at the PCT-induced hematopoietic aplasia, obtained according to the protocols of the main disease: severe combined immune deficiency (n = 2), idiopathic aplastic anaemia (n = 3), solid tumor (n = 2), acute myeloblastic leukemia (n = 7), acute lymphoblastic leukemia (n = 2). The main criterion for adding to the study was the existence at the least one site with a verified gram-negative infection (Pseudomonas aeruginosa, Klebsiella pneumoniae, Enterobacter cloacae, Stenotrophomonas maltophilia): bacteriemia (n = 11), oral mucosa (n = 6), ulcerative necrotic damage of perineum (n = 6), enterocolite (n = 6), infectionseptic compartments in the subcutaneous fat (n = 4), pleuropneumonia (n = 4), abscesses and inflammatory infiltration of the liver, spleen, pancreas, kidneys, lymph nodes (n = 1), infection of soft tissues in the area of the ventricular bypass with inflammatory changes of the brain membranes (n = 1).

All patients received 0.5 % of the solution of dioxin by injection according of vital importance, as they had pathogens with confirmed laboratory resistance or clinical progression of the infectious process against the background of combined antibacterial therapy.

Discussion. There is a complete control of fulminant developing infectious-septic processes caused by polyresistant micro-organisms against the background of hydroxymethylquinoxaline dioxide therapy in all 16 patients. The eradication of the pathogen, according to the microbiological study, has been confirmed in almost all observed patients, the efficacy of the drug has been preserved throughout the period of treatment, and the resistance of micro-organisms has not been observed. Strict adherence to the dosing and infusion technique of hydroxymethylquinoxaline dioxide has helped to achieve the full resolution of the infection process in all children without side-effects.

Conclusion. On the basis of the experience presented, in immunocomputed patients of young age, 0.5 % dioxidine solution can be used as a necessary reserve preparation for the treatment of the most severe forms of infections of different localization, caused by polyresistant strains of gram-negative micro-organisms.

Introduction. Neuroblastoma (NB) in children is a rare disease, accounting for 7 % of all cases of oncological diseases in childhood. In this regard, epidemiological analysis requires the accumulation of data over a long period of time. The purpose of the study is to study the morbidity, mortality and survival rate of children 0–14 years old with NB in the Republic of Belarus (RB).

Materials and methods. Based on the data from the children’s cancer subregister, morbidity, mortality and survival rates in child population were calculated from 1997 to 2017. A comparative epidemiological analysis was carried out in 2 time periods (1997–2007, 2008–2017).

Results and discussion. The incidence rate of NB in the RB, standardized for age, was 1.142 ± 0.062 per 100 000 child population with an average annual growth rate of 3.2 % per year. The mortality rate for this period was 0.32 ± 0.03 per 100 000 child population, an increase of 0.51 % per year. The main cause of death in patients with NB is the recurrence of the underlying disease. In 2008, a single protocol was used to treat all risk groups, which led to a significant increase in the observed population survival rate from 56 % (1997–2007) to 72 % (2008–2017) (p = 0.0041). Comparing the age structure of morbidity in Germany and the RB, it is noted that we have a reliably later diagnosis of the disease in the age categories from 0 to 1 year, from 1 to 4 years, from 5 to 9 years. The median age of the patient at the time of diagnosis in Germany is 1 year and 2 months, in our country 1 year and 6 months.

Conclusion. Indicators of standardized morbidity and mortality from NB in the RB correspond to the indicators of cancer registries in Western Europe and the USA. However, analyzing the age of the specific incidence of the disease, insufficient diagnosis of the disease is noted in the periods from 0 to 1 year, from 1 to 4 years and from 5 to 9 years compared to the data in Germany. This requires further improvement of the pediatric oncology service in the country.

Primary central nervous system lymphomas (PCNSL) are very rare and one of the most aggressive variants of extranodal nonHodgkin’s lymphomas (NHL). PCNSL comprise from 4 to 7 % of malignant tumors of the central nervous system in adults, and their true frequency in children is unknown. In the last few decades, the frequency of PCNSL has been increasing, possibly due to an increase the number of people with primary and secondary immunodeficiencies, although PCNSL are also diagnosed in people without an immunodeficiency condition. Due to the rare occurrence of PCNSL in children and adolescents, the clinical and morphoimmunological features of this extranodal variant of NHL need to be generalized and systematized. No less important problem is the choice of therapeutic tactics for PCNSL therapy in children. Current review presents the world and domestic experience in the diagnosis and treatment of pediatric and adolescent PCNSL. 

Данный обзор литературы посвящен проблеме брахитерапии у больных ретинобластомой и включает обобщенные данные об истории развития метода и его эффективности, технике операции, видах офтальмоаппликаторов и радиоизотопов, рекомендуемых дозах облучения и возможных осложнениях. Особое внимание в данной статье уделено изотопам рутения (Ru-106) и стронция (Sr-90) ввиду их использования на территории Российской Федерации. Для формирования обзора были использованы отечественные и зарубежные источники литературы, опубликованные в период с 1931 г. по настоящее время. 

Osteogenic sarcoma (OS) and Ewing sarcoma (ES) are the most common bone sarcomas in children, adolescent and young adults. Patients with metastatic, relapse or refractory disease have unfavorable prognosis: 5-year overall survival does not exceed 20–30 %. Nowadays clinical trials are conducted to find out new targets and ways of influencing these tumors. The aim of this review is to present relevant data from world literature about potential effective targeted drugs for patient with metastases, relapse or refractory OS and ES. 

Knowledge about the mechanisms of action of mesenchymal multipotent stromal cells (MSC) has undergone a significant evolution since their discovery. From the first attempts to use the remarkable properties of MSC in restoring the functions of organs and tissues, the most important question arose – how safe their use would be? One of the aspects of safety of the use of such biomaterial is tumorogenicity and oncogenicity. Numerous studies have shown that the mechanisms by which MSC realize their regenerative potential can, in principle, have a stimulating effect on tumor cells. This review presents specific mechanisms that have a potentially pro-tumor effect, which include the homing of MSC to the tumor site, support for replicative and proliferative signaling of both cancer cells and cancer stem cells, angiogenesis, and effects on the epithelial-mesenchymal transition. Along with pro-tumor mechanisms, the mechanisms of possible antitumor action are also described – direct suppression of tumor growth, loading and transportation of chemotherapeutic agents, oncolytic viruses, genetic modifications for targeting cancer, delivery of “suicide genes” to the tumor. Also, in conclusion, a small review of the current clinical trials of MSC as antitumor agents for malignant neoplasms of various localization (gastrointestinal tract, lungs, ovaries) is given. 

Neurofibromatosis is a genetic disorder that affects the bones, soft tissues, skin, and the nervous system. Neurofibromatosis has been described in 1882, however, there is still no specific treatment for this disease and no treatment protocols for the most frequent and life-threatening complications such as non-malignant tumors deriving from the cells of the peripheral nerve sheaths. Progress in molecular genetic study discovered the underlying genetic alteration in this tumor. This knowledge provides the base for clinical trials with new drugs. MEK-inhibitors are acting on the RAS-MAPK signaling pathway and have shown their efficacy in decreasing the size of inoperable tumors in children with type 1 neurofibromatosis (NF1). Although, this therapy does not completely reduce the tumor volume, it can significantly improve the quality of life. This article presents a clinical case of the trametinib efficacy in a child suffering from NF1-associated plexiform neurofibromas. 

The article presents a clinical case of simultaneous multiple primary tumors (the left adrenal neuroblastoma and the right lower parathyroid adenoma) in the child 11 years old.

The literature describes several cases of primarily multiple tumors, one of which was neurogenic, requiring an individual approach to treatment. The relationship between the occurrence of polyneoplasia and genetic mutations is discussed.