Introduction. Atypical teratoid/rhabdoid tumor (ATRT) of the central nervous system (CNS) belongs to the embryonic group, occurs mainly in children under 3 years of age and is characterized by an extremely aggressive clinical course and unfavorable outcome. However, there is not enough data about the heterogeneity of the clinical course of CNS ATRT and the role of clinical and therapeutic prognostic factors in patients under 1 year of age and 1–3 years of age.

The aim of this study was to conduct a comparative evaluation of treatment results in children with CNS ATRT in the indicated age groups.

Materials and methods. From 2008 till 2021 years 106 patients were included in this study. Each patient underwent a therapeutic program according to determined protocol (ATRT-2006, MUV-ATRT, EU-RHAB and individual variant). All patients were divided into 2 groups according to age: from 1 to 12 months – 41 patients, from 13 to 36 months – 65. Median of the age was 16 (9–23) months. These cohorts of patients (1–12 months and 13–36 months) were comparable in clinical and therapeutic characteristics depending on gender, localization of the primary tumor site, stage of the disease, extent of surgical resection, therapeutic protocol, number of patients, who underwent radiation therapy (RT), high-dose chemotherapy (HDCT) with autologous hematopoietic stem cell transplantation (auto-HSCT), intrathecal/ intraventricular chemotherapy.

Results. At the time of analysis 48 (45.3 %) patients were alive, 58 (54.7 %) patients died, of whom 52 (90 %) from disease progression and 6 (10 %) from therapeutic complications. One-year progression-free survival (PFS) in the group from 1 to 12 months was 32 %, 2-year – 18 %, 5-year – 18 %; one-year overall survival (OS) – 53 %, 2-year – 29 %, 5-year – 25 % with a median follow-up 8 and 13 months respectively. One-year PFS in the group from 13 to 36 months was 61 %, 2-year – 36 %, 5-year – 33 %; one-year OS – 86 %, 2-year – 67 %, 5-year – 49 % with a median follow-up 19 and 38 months respectively. In our study we identified the main predictors of the PFS and OS improvement in patients with ATRT CNS of each age group. In the 1–12 month group, these factors were: absence of metastatic involvement, MUV-ATRT therapeutic protocol, RT and HDCT with auto-HSCT; in the 13–36 months group: gross total/near gross total resection of the primary tumor cite, ATRT-2006 therapeutic protocol and RT.

Conclusion. Despite the fact, that the presence of a diagnosis of ATRT CNS in children under 3 years of age is usually associated with a high risk of disease progression and recurrence, the results of our study demonstrate the heterogeneity of the clinical and therapeutic profile in this age group of patients.

Currently, the use high doses chemotherapy (HDC) supported by autologous peripheral blood stem cells in consolidation is a necessary therapeutic option in patients with high-risk neuroblastoma (NB). Conditioning regimens and schemes of HDC remain the subject of debate. 

In recent years, the evidence base of the advantages of tandem myeloablative procedures in comparison with single-transplantation has been actively accumulated in clinical practice. This article presents our own experience of tandem-transplantation with stem cell rescue in the N.N. Petrov National Medical Research Centre of Oncology (Saint-Petersburg) in four patients with initially stratified high-risk group NB; two of them were NMYC amplified. Tandem consolidation included TC ([T]hiotepa, [C]yclophosphamide) and CEM ([C]arboplatin, [E]toposide, [M]elphalan) regimens. The acceptable toxicity of the tandem-transplantation is proved.

Introduction. As well as standard anticoagulants, direct oral anticoagulants (DOAC) have been approved for treatment of thromboembolism in children, recently. Several clinical trials provide promising data on efficacy and safety of DOAC in children and young adults. But further studies aimed at evaluating the efficacy and safety of these drugs in children and adolescents are still needed.

The aim of the study is to evaluate the safety and effectiveness of the use DOACs in children.

Materials and methods. We have retrospectively analyzed the medical records of patients (0–17 years) of from 2013 to 2022 at our tertiary care Centre and selected patients, who were treated with apixaban, rivaroxaban or dabigatran for more than 14 days. Patients with arterial thrombosis, children, who were treated with combined anticoagulant therapy and those who were unable for follow-up were excluded. We assessed the rates of bleeding and recurrent venous thromboembolism (VTE).

Results. There were 67 patients, who were treated with DOAC in our center. Patients were divided into 2 groups: those, who received prophylactic anticoagulation (group 1 – 6 patients), and patients, who received DOAC therapy after venous thromboembolism (group 2 – 61 patients). The median follow-up time was 46 (25–365) days in the group 1, and 4 months (2 weeks – 36 month) in the group 2. There were no VTE episodes and 1 minor bleeding in group 1, while 1 (2 %) major, 4 (6 %) minor bleeding episodes in group 2. There were 4 (6 %) patients with recurrent VTE in group 2.

Conclusion. The majority of patients in this study received rivaroxaban (79 %). We found a moderately increased recurrence rate of VTE, which could be the result of a long follow-up period, and a comparable rate of bleeding, all of which were associated with rivaroxaban therapy. In the future, of particular interest, in our opinion, are prospective studies of DOACs as primary antithrombotic prophylaxis, as well as secondary prophylaxis in the highest-risk groups, and the results of an analysis of their use in real clinical practice.

Relevance. Juvenile xanthogranuloma (JXG) is the most common form of non-Langerhans cell histiocytic disorder. Cutaneous forms of the disease spontaneously regress within a few years, while systemic forms of JXG require treatment and may pose a threat to the lives of patients. Due to the lack of unified approach to the treatment of multisystem forms of JXG, the question of effective therapy tactics remains unresolved. The most common approach is to use Langerhans cell histiocytosis (LCH) treatment regimens for JXG. With the understanding of the leading role of mutations in the MEK-ERK signaling pathway in the pathogenesis of JXG, targeted therapy, BRAF- and MEK-inhibitors, are increasingly being considered in the treatment of JXG.

Clinical cases. We present two cases of multisystem JXG with central nervous system (CNS) lesions. The first patient with CNS and skin lesions was treated with chemotherapy, developed for the treatment of multisystem LCH, which allowed us to obtain an effect “active disease better” (AD better). The second JXG patient with brain, lungs, bones, and adrenal gland lesions, combined targeted therapy with BRAF- and MEKinhibitors, vemurafenib and cobimetinib, resulted in a “non active disease” (NAD) effect.

Conclusion. Multisystem form of JXG with CNS involvement is a rare oncological disease, the therapy of which has not been developed. With the introduction of molecular genetic profiling technology, it became possible to obtain NAD effect using targeted therapy.

The aim of this work is to evaluate the informativity of the ultrasound (US) in detecting retinoblastoma (RB) and the local invasion of the tumor in children using modern multi-purpose ultrasound scanners.

Materials and methods. This study included 108 patients (216 eyes) examined for suspected RB. RB was diagnosed in 91 patients, 60 children had unilateral tumor, 31 – bilateral tumor (122 eyes). In the remaining 17 children (20 eyes damaged), different non-tumor pathology of the eye was revealed. Among 122 eyes affected by RB, 51 were removed with subsequent histological examination. 27 eyes were removed before treatment, 24 – after chemotherapy.

Results. In our study the informativity of ultrasound in detecting RB are: sensitivity – 98.4 %, specificity – 96.8 %, accuracy – 97.7 %. Sensitivity, specificity and accuracy in assessing tumor invasion to the anterior segment of the eye are 36.4 %, 95.0 % and 82.4 % respectively, to the vitreous body – 97.7 %, 100 % and 97.9 %, to the optic nerve – 54.5 %, 57.1 % and 54.9 %.

Conclusion. US examination using linear transducers of 9–18 MHz is highly informative in detecting RB, however, some indicators of the effectiveness in assessing local invasion are not high enough, due to the technical possibilities of the method. One possible way to improve the informativity – to use deep sedation during US examination.

There is no doubt that allogeneic hematopoietic stem cell transplantation (allo-HSCT) is one of the most effective treatments for many serious diseases. However, despite significant progress, allo-HSCT is still associated with a high rate of complications and mortality in the posttransplant period due to the toxicity of conditioning regimens, infectious and immune conditions. Acute complications such as endothelial injury, acute and chronic graft-versus-host disease (GVHD) remain the main causes of mortality after allo-HSCT. In our clinical case, we demonstrated an example of the development of such life-threatening complications as transplant-associated thrombotic microangiopathy and GVHD in a patient after repeated allo-HSCT, as well as the successful relief of these complications by modern therapeutic methods, including the introduction of closely related donor mesenchymal stem cells and the complement blocker eculizumab.

Synovial sarcoma (SS) is a soft tissue tumor that occurs among a group of tumors other than rhabdomyosarcoma (RMS) in childhood and adolescence in 4 % of cases. In terms of incidence among children, SS is second only to RMS and most often occurs in young and mature patients (15–35 years), with a slight predominance in men. The localization of SS in the soft tissues of the extremities reaches 80 %; to a lesser extent, these tumors occur in the head and neck, trunk, retroperitoneal space, and joints (no more than 5 %). Cases of the appearance of SS in the mediastinum, peripheral nerves, skin and visceral organs are also described.

This article presents a rare clinical case of the development of SS of the median nerve of the right shoulder in a 15-year-old patient.

malignant neoplasms (MNP). The frequency of PNS in MNP ranges from 1 to 20 % according to different authors. One of the manifestations of PNS is acne, which occurs against the background of malignant neoplasm due to hormonal disorders.

The presented article describes a clinical case of a patient with a mixed germ cell tumor and metastases in the retroperitoneal lymph nodes. The germ cell tumor produced human beta-chorionic gonadotropin, which led to the development of acne as a PNS.

Antitumor treatment (surgical removal of the tumor and polychemotherapy) normalized the levels of human beta-chorionic gonadotropin and serum testosterone, which in turn led to regression of acne without acne therapy.