Identification and characterization of stromal-like cells with CD207+/low CD1a+/low phenotype derived from histiocytic lesions - a perspective in vitro model for drug testing.

BACKGROUND: Histiocytoses are rare disorders manifested by increased proliferation of pathogenic myeloid cells sharing histological features with macrophages or dendritic cells and accumulating in various organs, i.a., bone and skin. Pre-clinical in vitro models that could be used to determine molecular pathways of the disease are limited, hence research on histiocytoses is challenging. The current study compares cytophysiological features of progenitor, stromal-like cells derived from histiocytic lesions (sl-pHCs) of three pediatric patients with different histiocytoses types and outcomes. The characterized cells may find potential applications in drug testing. METHODS: Molecular phenotype of the cells, i.e. expression of CD1a and CD207 (langerin), was determined using flow cytometry. Cytogenetic analysis included GTG-banded metaphases and microarray (aCGH) evaluation. Furthermore, the morphology and ultrastructure of cells were evaluated using a confocal and scanning electron microscope. The microphotographs from the confocal imaging were used to reconstruct the mitochondrial network and its morphology. Basic cytophysiological parameters, such as viability, mitochondrial activity, and proliferation, were analyzed using multiple cellular assays, including Annexin V/7-AAD staining, mitopotential analysis, BrdU test, clonogenicity analysis, and distribution of cells within the cell cycle. Biomarkers potentially associated with histiocytoses progression were determined using RT-qPCR at mRNA, miRNA and lncRNA levels. Intracellular accumulation of histiocytosis-specific proteins was detected with Western blot. Cytotoxicyty and IC50 of vemurafenib and trametinib were determined with MTS assay. RESULTS: Obtained cellular models, i.e. RAB-1, HAN-1, and CHR-1, are heterogenic in terms of molecular phenotype and morphology. The cells express CD1a/CD207 markers characteristic for dendritic cells, but also show intracellular accumulation of markers characteristic for cells of mesenchymal origin, i.e. vimentin (VIM) and osteopontin (OPN). In subsequent cultures, cells remain viable and metabolically active, and the mitochondrial network is well developed, with some distinctive morphotypes noted in each cell line. Cell-specific transcriptome profile was noted, providing information on potential new biomarkers (non-coding RNAs) with diagnostic and prognostic features. The cells showed different sensitivity to vemurafenib and trametinib. CONCLUSION: Obtained and characterized cellular models of stromal-like cells derived from histiocytic lesions can be used for studies on histiocytosis biology and drug testing.

Predictors of pulmonary metastases on chest computed tomography in children and adolescents with osteosarcoma-tips for qualifying patients for thoracotomy.

BACKGROUND: Osteosarcoma is the most common primary malignant bone tumour in children and adolescents. Lungs are the most frequent and often the only site of metastatic disease. The presence of pulmonary metastases is a significant unfavourable prognostic factor. Thoracotomy is strongly recommended in these patients, while computed tomography (CT) remains the gold imaging standard. The purpose of our study was to create tools for the CT-based qualification for thoracotomy in osteosarcoma patients in order to reduce the rate of useless thoracotomies. METHODS: Sixty-four osteosarcoma paediatric patients suspected of lung metastases on CT and their first-time thoracotomies (n = 100) were included in this retrospective analysis. All CT scans were analysed using a compartmental evaluation method based on the number and size of nodules. Calcification and location of lung lesions were also analysed. Inter-observer reliability between two experienced radiologists was assessed. The CT findings were then correlated with the histopathological results of thoracotomies. Various multivariate predictive models (logistic regression, classification tree and random forest) were built and predictors of lung metastases were identified. RESULTS: All applied models proved that calcified nodules on the preoperative CT scan best predict the presence of pulmonary metastases. The rating of the operated lung on the preoperative CT scan, dependent on the number and size of nodules, and the total number of nodules on this scan were also found to be important predictors. All three models achieved a relatively high sensitivity (72-92%), positive predictive value (81-90%) and accuracy (74-79%). The positive predictive value of each model was higher than of the qualification for thoracotomy performed at the time of treatment. Inter-observer reliability was at least substantial for qualitative variables and excellent for quantitative variables. CONCLUSIONS: The multivariate models built and tested in our study may be useful in the qualification of osteosarcoma patients for metastasectomy through thoracotomy and may contribute to reducing the rate of unnecessary invasive procedures in the future.

Gorham-Stout disease involving ipsilateral clavicle and scapula in a child - a case report focusing on imaging and histopathological features of this extremely rare condition.

Gorham-Stout disease (GSD) is a very rare entity of unknown etiology, characterized by excessive intra-osseous proliferation of blood or lymphatic vessels, resulting in progressive resorption of bone matrix and destruction of bone. To date we have found only seven published cases concerning fully confirmed GSD of the shoulder girdle bones in children. Our case concerns an 8-year-old boy with involvement of the left clavicle and scapula. The knowledge of imaging and histopathological features is crucial for establishing the diagnosis of GSD, therefore the exchange of experiences in this field is essential for improving the care of affected patients.

Mutational landscape of primary and recurrent Ewing sarcoma.

INTRODUCTION: Ewing sarcoma (ES) is a highly aggressive malignancy of bone and soft tissues characterized by the presence of a genetic fusion involving the EWSR1 gene. More than one-third of patients develop distant metastases, which are associated with unfavorable prognosis. Knowledge about the disease's genetic landscape may help foster progress in using targeted therapies in the treatment of ES. AIM OF THE STUDY: The objective is to assess the mutational landscape of ES in pretreatment samples, tumor samples after neoadjuvant chemotherapy, and in metastatic/recurrent tumors in children and adults. MATERIAL AND METHODS: DNA from 39 formalin-fixed paraffin-embedded tumor samples of 22 patients (17 adults, 5 children) were analyzed by targeted next generation sequencing (NGS) using the Oncomine Comprehensive Assay v3gene panel. Additional functional analyses were performed between patient subgroups. RESULTS: All samples were characterized by low tumor mutation burden (< 10 mut/Mb). The most commonly mutated genes were PIK3R1 (59%) and POLE (50%). The most widely detected variants in biopsy samples were PIK3R1 T369I (50%), FGFR1 E159K, and TP53 at codon 72 (both in 27.3%). Additionally, the ATR,BRCA1, RAD50,ATM,CHEK1, and NBN genes showed a significantly higher number of mutations in ES. Mutations in PIK3R1 were significantly more frequent in adults, while mutations in the pathways responsible for cell cycle control, DNA repair, and transcriptional regulation were more frequent in children. CONCLUSIONS: Besides EWSR1 fusion, ES is characterized by numerous point mutations that are potential targets for precision medicine. There is high genomic heterogeneity that may explain differences in outcomes between patient subgroups.

Clinical characteristics and outcome of pediatric patients diagnosed with Langerhans cell histiocytosis in pediatric hematology and oncology centers in Poland.

BACKGROUND: Langerhans cell histiocytosis (LCH) affects 1-2 in 1,000,000 people. The disease is not associated with increased risk of treatment failure (especially among older children), but appropriate procedures implemented in advance can eliminate complications which might appear and significantly worsen the patients' quality of life. Thus, we sought to evaluate the clinical features, management, and outcome of children with LCH treated in Polish pediatric hematology-oncology centers. MATERIALS AND METHODS: One hundred eighty two patients with LCH were treated according to the Histiocytic Society Guidelines between 2010 and 2017. The participating centers were requested to provide the following data: demographic, clinical, as well as local or systemic treatment data and patients' outcome. Overall survival (OS) and event free survival (EFS) were estimated by Kaplan-Meier methods and compared using the log-rank test. RESULTS: Sixty nine percent of children were classified as single system (SS). The patients with SS disease were significantly older as compared to the children with multisystem disease (MS), 6 vs. 2.3 years respectively (p 0.003). Bones were involved in 76% of patients. Systemic treatment was applied to 47% of children with SS disease and 98% with MS disease. Fourteen patients relapsed while two children died. OS and EFS in entire group were 0.99 and 0.91 respectively (with median follow-up 4.3 years). CONCLUSION: The treatment of LCH in Polish centers was effective, however, new approaches, including mutation analyses and good inter-center cooperation, are needed to identify patients who might require modification or intensification of treatment.

Feasibility and Safety of Treosulfan, Melphalan, and Thiotepa-Based Megachemotherapy with Autologous or Allogeneic Stem Cell Transplantation in Heavily Pretreated Children with Relapsed or Refractory Neuroblastoma.

The prognosis of resistant or relapsing children with neuroblastoma remains very poor, and the search for new therapies is ongoing. In this analysis, we assessed the toxicity of a treosulfan, melphalan, and thiotepa (TMT) regimen in 17 children with recurrent or refractory neuroblastoma who underwent stem cell transplantation (SCT). For allogeneic SCT, fludarabine and antithymocyte globulin were added. The stem cell source was autologous in 8 patients, haploidentical in 8 patients, and a matched unrelated donor in 1 patient. The reported nonhematologic toxicities included grade 3 mucositis, grade 1 to 3 hypertransaminasemia, and in 3 patients, veno-occlusive disease. No neurologic, cardiac, or dermatologic toxicities were observed. The probability of overall survival (OS) in patients with primary resistance was superior to that in patients with relapsed disease (100% versus 22.6%; P = .046). Post-transplantation dinutuximab beta immunotherapy was associated with superior 5-year OS (66.7% versus 11.4%; P = .0007). The use of an allogeneic donor, previous autologous SCT with busulfan and melphalan, and pretreatment with high-dose metaiodobenzylguanidine therapy demonstrated no effect on outcomes. In 4 patients, TMT megatherapy alone was enough to achieve complete remission. The TMT conditioning regimen was well tolerated in heavily pretreated patients with neuroblastoma. The manageable toxicity and addition of new anticancer drugs with optional post-SCT immunotherapy or chemotherapy support further trials with the TMT regimen in patients with neuroblastoma.

Predicting Ewing Sarcoma Treatment Outcome Using Infrared Spectroscopy and Machine Learning.

BACKGROUND: Improved outcome prediction is vital for the delivery of risk-adjusted, appropriate and effective care to paediatric patients with Ewing sarcoma-the second most common paediatric malignant bone tumour. Fourier transform infrared (FTIR) spectroscopy of tissues allows the bulk biochemical content of a biological sample to be probed and makes possible the study and diagnosis of disease. METHODS: In this retrospective study, FTIR spectra of sections of biopsy-obtained bone tissue were recorded. Twenty-seven patients (between 5 and 20 years of age) with newly diagnosed Ewing sarcoma of bone were included in this study. The prognostic value of FTIR spectra obtained from Ewing sarcoma (ES) tumours before and after neoadjuvant chemotherapy were analysed in combination with various data-reduction and machine learning approaches. RESULTS: Random forest and linear discriminant analysis supervised learning models were able to correctly predict patient mortality in 92% of cases using leave-one-out cross-validation. The best performing model for predicting patient relapse was a linear Support Vector Machine trained on the observed spectral changes as a result of chemotherapy treatment, which achieved 92% accuracy. CONCLUSION: FTIR spectra of tumour biopsy samples may predict treatment outcome in paediatric Ewing sarcoma patients with greater than 92% accuracy.

[Vemurafenib in refractory langerhans histiocytosis].

Langerhans Cell Histiocytosis (LCH) is a rare disease involving the occurrence of disturbances in the mitogene-activated kinases pathway (MAPK). At present, it is known that the appearance of such disorders is usually connected with a more aggressive form of the disease, more frequently resistant to conventional chemotherapy, as well as characterised by a higher probability of relapse and progression. Since recently, it has been possible to apply BRAF inhibitors in the treatment of LCH patients, however, there are no clear guidelines regarding the criteria for implementing this type of therapy. There are very little literature data as to the safety of using such formulations among juvenile patients. In this paper we present a girl with severe Langerhans Cell Histiocytosis, not responding to conventional treatment, who only after adding vemurafenib achieved a regression of symptoms. This case shows the necessity to expand the diagnostics with molecular tests and the possibility of applying targeted treatment for patients of this kind.

Ovarian function in female survivors after multimodal Ewing sarcoma therapy.

BACKGROUND: With advances in cancer care, more young women with Ewing sarcoma (ES) survive after treatment. Thus, we sought to analyze the ovarian function in prepubertal, pubertal and postpubertal females and young women receiving multimodal therapy for ES, and to identify patients at risk of infertility on whom fertility preservation would be indicated. PROCEDURES: Twenty-seven female survivors of ES were included in this retrospective multiinstitutional study. Patients were classified into four groups according to the treatment received: chemotherapy (CHT) without pelvic radiation (pRT), chemotherapy and pRT, CHT and autologous hematopoietic cell stem rescue (aHSCT) without pRT, and CHT + pRT + aHSCT. The ovarian function and fertility outcomes were analyzed. RESULTS: At a median follow-up of 5.7 years from diagnosis, and at median age at follow-up of 16.3 years, 67% of the survivors had premature ovarian insufficiency, including all patients receiving pelvic RT and 87.5% of patients who underwent aHSCT, independent of chemoprotection. Thirty-seven percent of patients had a clinical syndrome of premature menopause. The relative risk (RR) of premature ovarian insufficiency of a survivor was 3.9 (p 0.03) for pRT, and 2.4 (p 0.07) for aHSCT. On multivariate analysis, radiation therapy was a significant predictor of higher risk of premature ovarian insufficiency over chemotherapy alone. CONCLUSIONS: A large proportion of women receiving multimodal therapy for ES develop premature ovarian insufficiency. Patients and guardians should be informed about the reproductive potential and strategies for preservation of ovarian function should be considered individually. Pediatr Blood Cancer 2015;62:341-345. © 2014 Wiley Periodicals, Inc.

Effective treatment of cytomegalovirus retinitis and neuritis with retrobulbar ganciclovir after treosulfan-based autologous bone marrow transplant.

We describe the case of a 16-month-old girl with neuroblastoma and chronic lymphocytopenia due to chemotherapy and treosulfan-containing megatherapy who developed cytomegalovirus retinitis and neuritis. Intravenous ganciclovir and anti-cytomegalovirus immunoglobulin were used with a transient benefit; however, retrobulbar gancyclovir resulted in a complete remission. This report emphasizes the need for close monitoring of viral infections in patients undergoing treosulfan-containing megatherapy, highlighting the immunosuppressive effects of this agent, and indicates the potential use of retrobulbar ganciclovir as the alternative method of drug delivery.

Validation of a multi-modal treatment protocol for Ewing sarcoma--a report from the polish pediatric oncology group.

BACKGROUND: Ewing sarcoma (ES) is the second most common paediatric malignant bone tumor. Advances in multi-disciplinary care have resulted in significant improvement in cure rates over the last decades. However, the generalization of those results in countries traditionally excluded from large cooperative trials has yet to be demonstrated. We report the results of modern multi-disciplinary care for patients with ES in Poland. PROCEDURES: One hundred and thirty-two patients with ES were treated using modern multi-modal therapy during the period 2000-2009. Overall survival was estimated by Kaplan-Meier methods and compared using long-rank test and Cox models. Factors predictive of outcome in our setting were analyzed to identify distinct risk groups that could help identify areas for improvement. RESULTS: The median age at the time of diagnosis was 12.3 years. With a median follow-up of 5.0 years, the 5-year event-free survival (EFS) and OS estimates for localized disease were 54.88% and 68.29%, respectively. For patients with metastatic disease, 5-year EFS and OS estimates were 36% and 42%, respectively. There was no correlation between age and stage or site. Patients with localized, non-pelvic disease had better outcome than patients with axial tumors (71% vs. 44%, respectively, P = 0.00073). Treatment failure was associated with stage, pelvic primary, poor histological response, and type of local control. CONCLUSIONS: Successful treatment of ES requires optimal systemic and local therapy. We were able to replicate the results of modern multi-modal protocols. Validation of current treatment protocols in countries with more limited cancer treatment resources is required.

Revisiting the role of radiotherapy in the treatment of neuroblastoma 4S: 30 years of institutional experience and systematic review.

Background and purpose: Neuroblastoma 4S is a rare subtype of metastatic neuroblastoma found in children younger than 12 months, characterized by liver, skin, or bone marrow metastases. While the prognosis for patients is generally favorable, rapid progression of liver metastases can lead to life-threatening organ insufficiency. In such cases, immediate treatment with chemotherapy or radiotherapy is necessary. Given the recent decline in radiotherapy utilization, this study aims to reassess its role, evaluating its effectiveness and toxicity. Materials and methods: We conducted a systematic review and an institutional retrospective analysis to assess the use of radiotherapy for hepatomegaly in patients with neuroblastoma 4S. The study included data from 164 patients from the literature and 16 patients from our institutional cohort. We extracted and analyzed data on short- and long-term outcomes, as well as reports of radiotherapy-induced toxicity. Results: Our institutional data showed that 81 % of patients responded to low-dose radiotherapy administered at a median dose of 450 cGy in three fractions, resulting in liver shrinkage and symptom resolution. Based on the systematic review, 1-year survival rate was 80 %, while 5-year survival rate was 75 %. No serious toxicity was observed with the current low-dose radiotherapy; however, one case of induced secondary malignancy was reported. Conclusion: Radiation therapy is an effective treatment modality for hepatomegaly in patients with neuroblastoma 4S, with a success rate of about 80 %. Despite being administered to infants, a low dose of 450-600 cGy does not result in toxicity related to the kidneys, liver, or posture defects.

Factors Influencing the Outcome of Patients with Primary Ewing Sarcoma of the Sacrum.

Background: Ewing sarcoma (EwS) is a rare and highly malignant bone tumor primarily affecting children, adolescents, and young adults. The pelvis, trunk, and lower extremities are the most common sites, while EwS of the sacrum as a primary site is very rare, and only few studies focusing on this location are published. Due to the anatomical condition, local treatment is challenging in sacral malignancies. We analyzed factors that might influence the outcome of patients suffering from sacral EwS. Methods: We retrospectively analyzed data of the GPOH EURO-E.W.I.N.G 99 trial and the EWING 2008 trial, with a cohort of 124 patients with localized or metastatic sacral EwS. The study endpoints were overall survival (OS) and event-free survival (EFS). OS and EFS were calculated using the Kaplan-Meier method, and univariate comparisons were estimated using the log-rank test. Hazard ratios (HRs) with respective 95% confidence intervals (CIs) were estimated in a multivariable Cox regression model. Results: The presence of metastases (3y-EFS: 0.33 vs. 0.68; P < 0.001; HR = 3.4, 95% CI 1.7 to 6.6; 3y-OS: 0.48 vs. 0.85; P < 0.001; HR = 4.23, 95% CI 1.8 to 9.7), large tumor volume (≥200 ml) (3y-EFS: 0.36 vs. 0.69; P=0.02; HR = 2.1, 95% CI 1.1 to 4.0; 3y-OS: 0.42 vs. 0.73; P=0.04; HR = 2.1, 95% CI 1.03 to 4.5), and age ≥18 years (3y-EFS: 0.41 vs. 0.60; P=0.02; HR = 2.6, 95% CI 1.3 to 5.2; 3y-OS: 0.294 vs. 0.59; P=0.01; HR = 2.92, 95% CI 1.29 to 6.6) were revealed as adverse prognostic factors. Conclusion: Young age seems to positively influence patients` survival, especially in patients with primary metastatic disease. In this context, our results support other studies, stating that older age has a negative impact on survival. Tumor volume, metastases, and the type of local therapy modality have an impact on the outcome of sacral EwS. Level of evidence: Level 2. This trial is registered with NCT00020566 and NCT00987636.

Anti-PD-1 Therapy in Advanced Pediatric Malignancies in Nationwide Study: Good Outcome in Skin Melanoma and Hodgkin Lymphoma.

BACKGROUND/AIM: The role of immune checkpoint inhibitors (ICIs; anti-PD1) in the treatment of childhood cancers is still evolving. The aim of this nationwide retrospective study was to assess the safety and effectiveness of ICIs used in a group of 42 patients, with a median age of 13.6 years, with various types of advanced malignancies treated in pediatric oncology centers in Poland between 2015 and 2023. RESULTS: The indications for treatment with anti-PD1 were as follows: Hodgkin lymphoma (11); malignant skin melanoma (9); neuroblastoma (8); and other malignancies (14). At the end of follow-up, complete remission (CR) was observed in 37.7% (15/42) of children and disease stabilization in 9.5% (4/42), with a mean survival 3.6 (95% CI = 2.6-4.6) years. The best survival (OS = 1.0) was observed in the group of patients with Hodgkin lymphoma. For malignant melanoma of the skin, neuroblastoma, and other rare malignancies, the estimated 3-year OS values were, respectively, 0.78, 0.33, and 0.25 (p = 0.002). The best progression-free survival value (0.78) was observed in the group with malignant melanoma. Significantly better effects of immunotherapy were confirmed in patients ≥ 14 years of age and good overall performance ECOG status. Severe adverse events were observed in 30.9% (13/42) patients.

Biological sample collection to advance research and treatment: a Fight Osteosarcoma Through European Research (FOSTER) and Euro Ewing Consortium (EEC) statement.

Osteosarcoma and Ewing sarcoma are bone tumours mostly diagnosed in children, adolescents and young adults. Despite multi-modal therapy, morbidity is high and survival rates remain low, especially in the metastatic disease setting. Trials investigating targeted therapies and immunotherapies have not been ground-breaking. Better understanding of biological subgroups, the role of the tumour immune microenvironment, factors that promote metastasis and clinical biomarkers of prognosis and drug response are required to make progress. A prerequisite to achieve desired success is a thorough, systematic and clinically linked biological analysis of patient samples but disease rarity and tissue processing challenges such as logistics and infrastructure have contributed to a lack of relevant samples for clinical care and research. There is a need for a Europe-wide framework to be implemented for the adequate and minimal sampling, processing, storage and analysis of patient samples. Two international panels of scientists, clinicians and patient and parent advocates have formed the Fight Osteosarcoma Through European Research (FOSTER) consortium and the Euro Ewing Consortium (EEC). The consortia shared their expertise and institutional practices to formulate new guidelines. We report new reference standards for adequate and minimally required sampling (time points, diagnostic samples, liquid biopsy tubes), handling and biobanking to enable advanced biological studies in bone sarcoma. We describe standards for analysis and annotation to drive collaboration and data harmonisation with practical, legal and ethical considerations. This position paper provides comprehensive guidelines that should become the new standards of care that will accelerate scientific progress, promote collaboration and improve outcomes.

Vincristine, irinotecan, and temozolomide in patients with relapsed and refractory Ewing sarcoma.

BACKGROUND: Patients with metastatic, progressive or recurrent Ewing sarcoma (ES) have a dismal outcome. The combination of irinotecan and temozolomide has been proposed as an effective salvage regimen for some pediatric malignancies. Thus, we sought to evaluate this combination with vincristine for patients with relapsed and refractory ES. MATERIALS AND METHODS: Twenty-two patients with relapsed or refractory ES were treated with the combination of vincristine (1.5 mg/m(2) i.v. day 1), irinotecan (50 mg/m(2) /day i.v. days 1-5) and temozolomide (125 mg/m(2) /day p.o. days 1-5) (VIT) during the period 2008-2012. All toxicities were documented. RESULTS: A total of 91 cycles (median 4.1 cycles/patient) were administered. A complete response (CR) was achieved in five patients, partial response (PR) in seven patients, stable disease (SD) in three patients, and progression disease (PD) in seven patients, with an overall response rate of 68.1%. Median time to progression was 3.0 months (range 1.1-37.1 months). Five patients (22.7%) are alive with no evidence of disease with a median follow-up of 10.3 months (range 2.1-46.5); four of them received consolidation with high-dose chemotherapy and autologous hematopoietic stem cell transplant after responding to VIT. Outcome was better for patients with relapsed ES compared with patients who progressed to initial therapy (estimated 2 year overall survival 36.4% vs. 0%, respectively). There were no significant toxicities. CONCLUSIONS: The shorter, 5-day VIT regimen is an active and well-tolerated regimen in refractory ES. This combination deserves further investigation in the upfront management of patients with metastatic disease.

Interocular Symmetry of Choroidal Parameters in Patients with Diabetic Retinopathy with and without Diabetic Macular Edema.

This study focuses on the interocular comparison of choroidal parameters in diabetic patients with diabetic retinopathy (DR) with and without diabetic macular edema (DME), as well as in patients with unilateral DME (present in only one eye). The aim of this study was to determine the symmetry in order to obtain better insights into the pathophysiology of diabetic choroidopathy. This retrospective single-center cross-sectional study included 170 eyes from 85 patients (61 with DR and 24 controls), divided into subgroups depending on the presence of DME. The patients underwent fluorescein angiography and spectral domain optical coherence tomography examination, and the analysis included various choroidal parameters: choroidal thickness, volume, and the choroidal vascularity index (CVI). In terms of the choroidal thickness, one eye of a patient with DR, regardless of the presence, absence, or unilaterality of DME, may be treated as representative for that patient. CVI proved symmetrical for controls and patients with DR without DME. However, there was some asymmetry of CVI in patients with bilateral or unilateral DME. There was no straightforward relationship between choroidopathy and DME. Other mechanisms were also involved in the pathogenesis.

Rhabdomyosarcoma of the genitourinary system in girls - the role of magnetic resonance imagining in diagnosis, treatment monitoring, and follow-up.

OBJECTIVES: Rhabdomyosarcoma of the genitourinary system in girls is a rare neoplasm, especially in non-dedicated centers. Our work aimed to sum up and present genitourinary rhabdomyosarcomas in girls from the radiological point of view. MATERIAL AND METHODS: We retrospectively reviewed all girls with genitourinary RMS who underwent treatment at the Institute of Mother and Child in Warsaw between 2009 and 2022. We evaluated the demographic, clinical, and pathological patient data and imaging studies. RESULTS: During the study period, ten patients presented with genitourinary RMS and underwent magnetic resonance imaging (MRI). The median age at the time of diagnosis was 2.8 years, six patients were younger than three years, and four patients were older than ten years. The most common clinical symptoms were tumor fragments protruding from the vagina/falling out of the vagina and vaginal bleeding or discharge, and the most common original location was the vagina. One hundred percent of patients had the embryonal subtype of RMS, and 100% of cases where molecular tests for PAX3/FOXO1 fusion gen status were performed had negative status. At presentation, the median tumor volume was 114 cm³. Eight patients (80%) were classified as clinical group III according to the IRS Group, and most patients (70%) were in a standard-risk group. All patients received multimodal treatment, including surgery and chemotherapy; 60% received radiotherapy. Neoadjuvant chemotherapy was the primary treatment for all our patients. In six patients (60%) with a measurable tumor mass after a biopsy, a gradual tumor volume reduction was observed after induction chemotherapy (approximately ten weeks of treatment) - all of which had a partial response (PR). All our patients (100%) responded completely to treatment. CONCLUSIONS: MRI was performed at every stage of diagnosis and treatment as well as during follow-up. It allowed for staging, monitoring of chemotherapy, and guided surgery.