[MR Imaging Features of Pediatric Bone Marrow]

MRI plays a crucial role in bone marrow (BM) assessment, and has very high sensitivity in diagnosing marrow disorders. However, for radiologists who may not frequently encounter pediatric imaging, distinguishing pathologic BM lesion from normal BM can be challenging. Conditions involving the BM in pediatric patients, such as leukemia and metastatic neuroblastoma, often manifest with diverse musculoskeletal symptoms and may be diagnosed using musculoskeletal MRI examinations. Accurate interpretation of pediatric MRI requires not only an understanding of the normal composition of BM but also an awareness of agerelated developmental changes in the marrow and familiarity with conditions that commonly involve pediatric BM. We aim to describe the composition of normal BM and outline the normal and abnormal MRI findings in pediatric BM. Additionally, we aim to present clinical cases of malignant BM disorders including leukemia, neuroblastoma metastasis, and other malignant BM disorders.

Nomogram to predict prognosis of head and neck rhabdomyosarcoma patients in children and adolescents

Purpose

This study aims to explore the prognostic factors of head and neck rhabdomyosarcoma (HNRMS) in children and adolescents and construct a simple but reliable nomogram model for estimating overall survival (OS) of patients.

Methods

Data of all HNRMS patients during 2004-2018 were identified from the Surveillance, Epidemiology, and End Result database. Kaplan-Meier method was performed to calculate OS stratified by subgroups and comparison between subgroups was completed by log-rank test. Univariate and multivariate Cox regressions analysis were employed for identifying independent predictors, which subsequently were used for a predictive model by R software, and the efficacy of the model was evaluated by applying receiver operating curve (ROC), calibration and decision curve analysis (DCA).

Results

A total of 446 patients were included in the study. The 1-, 3-, and 5-year OS rate of the whole cohort was 90.6%, 80.0%, and 75.5%, respectively. The results of univariate and multivariate Cox regression analysis indicated that the primary site in parameningeal region, alveolar RMS histology, M1 stage, IRS stage 4, surgery, and chemotherapy were significant prognostic factors (all P<0.05). The performance of nomogram model was validated by discrimination and calibration, with AUC values of 1, 3, and 5 years OS of 0.843, 0.851, and 0.890, respectively.

Conclusion

We constructed a prognostic nomogram model for predicting the OS in HNRMS patients in children and adolescents and this model presented practical and applicable clinical value to predict survival when choosing treatment strategies.

Small bowel metastasis from embryonal rhabdomyosarcoma of the extremity- a case report

Rhabdomyosarcoma is the most common soft tissue tumour in children and adolescents, but extremely rare in adults with comparatively worse outcomes. Metastatic disease is not uncommon, but intra-abdominal metastases are exceedingly rare. We report an unusual case of ileal metastases from an upper extremity rhabdomyosarcoma in a 17-year-old male who presented with abdominal pain during a routine follow-up visit. Laparotomy and ileocecectomy for a perforated ileal mass confirmed metastatic embryonal rhabdomyosarcoma with 1 out of 14 positive lymph node metastases. This case demonstrates that, although rare, intra-abdominal metastases should be considered when patients with a rhabdomyosarcoma present with abdominal complaints.

Useful sonographic findings for diagnosing dermal metastases of rhabdomyosarcoma

Rhabdomyosarcoma developing in deep locations, such as the genitourinary tract, and perianal and perineal regions, symptoms may be obscure. Dermal rhabdomyosarcoma metastases may be first symptom of that and those arise in the subcutaneous fat tissue, presenting as a high echoic area surrounded by a low echoic area, accompanied by a high echoic peripheral area. These sonographic findings might indicate an aggressive malignant disease, and that would be useful to differentiate from other dermal lesions.

Impact of race and ethnicity on presentation and outcomes of patients treated on rhabdomyosarcoma clinical trials: A report from the Children's Oncology Group

BACKGROUND

Racial and ethnic disparities have been demonstrated in pediatric and adult cancers. However, there is no consensus on whether such disparities exist in the presentation, treatment, and outcome of patients with rhabdomyosarcoma (RMS).

METHODS

Patient information from the seven most recent RMS clinical trials was obtained from the Children's Oncology Group (COG). Chi-squared analyses were used to compare patient, tumor, and treatment characteristics across racial and ethnic groups. Pairwise analyses comparing Non-Hispanic Black (NHB) versus Non-Hispanic White (NHW) racial groups and Hispanic versus NHW ethnic groups were conducted for significant characteristics. Kaplan-Meier method and Wilcoxon signed-rank tests were performed to analyze outcomes.

RESULTS

In the overall cohort (n = 2157), patients' self-identified race/ethnicity was: 0.4% American Indian/Alaska Native, 2.6% Asian, 12.6% Hispanic, 0.2% Native American/other Pacific Islander, 12.8% NHB, 61.9% NHW, and 9.6% unknown. Six characteristics differed by race/ethnicity: age, histology, IRS group, invasiveness, metastatic disease, and FOXO1 fusion partner. Five were significant in pairwise comparisons: NHB patients were more likely to present at age ≥ 10 years and with invasive tumors than NHW patients; Hispanic patients were more likely to present with alveolar histology, metastatic disease, and IRS group IV disease than NHW patients. No differences were found in event free or overall survival of the entire cohort, in risk group-based subset analyses, or among patients with high-risk characteristics significant on pairwise analysis.

CONCLUSIONS

While NHB and Hispanic patients enrolled in COG trials presented with higher risk features than NHW patients, there were no outcome differences by racial or ethnic group.

Evaluation of the Immunological Response of Childhood Cancer Patients Treated with a Personalized Peptide Vaccine for Refractory Soft Tissue Tumor: A Four-Case Series

This case series aimed to evaluate the peptide-specific immunoglobulin G (IgG) response, clinical effectiveness, and the safety of a personalized peptide vaccine (PPV) in four children with refractory solid cancer. Although the pre-vaccination IgG responses were suppressed, IgG levels against the vaccinated peptides after 12 vaccinations were increased in all three cases who received at least 12 vaccinations. Vaccination-related adverse effects were grade 1 injection-site local skin lesions. One patient, whose diagnosis was relapsed rhabdomyosarcoma, remains in sustained remission after 37 months. Although the pre-vaccination immune response in this patient was low, IgG levels against 2 of the 4 peptide vaccines were increased after the sixth vaccination, followed by a strong increase at the eighteenth vaccination against all 4 peptides, with a >100-fold increase vs. 2 peptides. The remaining three patients exhibited progressive disease and eventually died of their original cancer. The results of the current case series suggest that in cases of childhood solid tumors, when the tumor is controlled at the time of entry PPV may have some consolidation effect. Therefore, PPV could be a new immunotherapy modality for refractory childhood solid tumors.

Rhabdomyosarcoma mimicking lymphoma

Background

Rhabdomyosarcoma (RMS) is a malignant soft tissue tumor that accounts for approximately one-half of soft tissue sarcomas in childhood age groups. Metastatic RMS is a rare condition that occurs in less than 25% of patients at diagnosis and can have variable clinical presentations.

Case presentation

Here we report a 17-year-old boy with history of weight loss, fever and generalized bone pain admitted for severe hypercalcemia. The definite diagnosis of RMS was performed with immune-phenotyping of the metastatic lymph-node biopsy. The primary tumor site was not found. His bone scan showed diffuse bone metastasis and significant soft tissue technetium uptake due to extra-osseous calcification.

Conclusion

Metastatic RMS can mimic lymphoproliferative disorders at presentation. Clinicians must be aware of this diagnosis especially in young adults.

Retroperitoneal alveolar rhabdomyosarcoma intruding into spinal canal: A case report and literature review

Background

Rhabdomyosarcoma (RMS) is the most frequent soft sarcoma in children and adolescents. Alveolar rhabdomyosarcoma (ARMS) is a relatively rare subtype that is characterized by aggressive behavior and an unsatisfactory prognosis. An ARMS can arise anywhere but most commonly occurs at extremity sites with a very small fraction in the retroperitoneum. The utility of 2-Deoxy-2-[fluorine-18]-fluoro-D-glucose (18F-FDG) positron emission tomography combined with computed tomography (PET/CT) remains to be established in ARMS.

Case Report

A 3-year-old female child was accidentally found with a large left upper abdominal mass for a day. CT examination indicated a huge soft tissue mass in the left retroperitoneum extending superiorly to the level of the left hilus renalis and inferiorly to the left acetabulum in the pelvic cavity, with intrusion into the lumbar foramens. 18F-FDG PET/CT found a mass in the left retroperitoneum from the level of T12 to the left acetabulum, with the maximum standardized uptake value (SUVmax) of about 7.0, and a CT value of about 39 HU, invading the left L3-5 intervertebral foramina and protruding into the spinal canal, with unclear boundary with the spinal cord. Retroperitoneal tumor resection and the repair operation of vascular exploration were performed. An ARMS was confirmed by postoperative biopsy, immunohistochemical staining, and genetic detection with the rupture of the fork head in rhabdomyosarcoma (FKHR). The patient received chemotherapy and was in a good condition with no recurrence and obvious complications.

Conclusion

Retroperitoneal ARMS is rare and indicates a poor outcome with the potential to involve vital organs and intrude into the spinal canal. Accurate diagnosis and staging using PET/CT would contribute to better risk stratifications and appropriate treatment individually.

Fisher discriminant model based on LASSO logistic regression for computed tomography imaging diagnosis of pelvic rhabdomyosarcoma in children

Computed tomography (CT) has been widely used for the diagnosis of pelvic rhabdomyosarcoma (RMS) in children. However, it is difficult to differentiate pelvic RMS from other pelvic malignancies. This study aimed to analyze and select CT features by using least absolute shrinkage and selection operator (LASSO) logistic regression and established a Fisher discriminant analysis (FDA) model for the quantitative diagnosis of pediatric pelvic RMS. A total of 121 pediatric patients who were diagnosed with pelvic neoplasms were included in this study. The patients were assigned to an RMS group (n = 36) and a non-RMS group (n = 85) according to the pathological results. LASSO logistic regression was used to select characteristic features, and an FDA model was constructed for quantitative diagnosis. Leave-one-out cross-validation and receiver operating characteristic (ROC) curve analysis were used to evaluate the diagnostic ability of the FDA model. Six characteristic variables were selected by LASSO logistic regression, all of which were CT morphological features. Using these CT features, the following diagnostic models were established: (RMS group)\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$${G}_{1}=-14.283+6.613{x}_{1}+5.333{x}_{2}+5.753{x}_{3}+12.361{x}_{4}+8.095{x}_{5}-0.715{x}_{6}$$\end{document}G1=-14.283+6.613x1+5.333x2+5.753x3+12.361x4+8.095x5-0.715x6; (Non-RMS group)\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$${G}_{2}=-2.008+3.539{x}_{1}+1.080{x}_{2}+1.154{x}_{3}+2.307{x}_{4}+1.656{x}_{5}+1.380{x}_{6}$$\end{document}G2=-2.008+3.539x1+1.080x2+1.154x3+2.307x4+1.656x5+1.380x6, where \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$${x}_{1}$$\end{document}x1, \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$${x}_{2}$$\end{document}x2, … and \documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$${x}_{6}$$\end{document}x6 are lower than normal muscle density (1 = yes; 0 = no), multinodular fusion (1 = yes; 0 = no), enhancement at surrounding blood vessels (1 = yes; 0 = no), heterogeneous progressive centripetal enhancement (1 = yes; 0 = no), ring enhancement (1 = yes; 0 = no), and hemorrhage (1 = yes; 0 = no), respectively. The calculated area under the ROC curve (AUC) of the model was 0.992 (0.982–1.000), with a sensitivity of 94.4%, a specificity of 96.5%, and an accuracy of 95.9%. The calculated sensitivity, specificity and accuracy values were consistent with those from cross-validation. An FDA model based on the CT morphological features of pelvic RMS was established and could provide an easy and efficient method for the diagnosis and differential diagnosis of pelvic RMS in children.

Polymeric nanoparticles surface-complexed with boric acid actively target solid tumors overexpressing sialic acid

Sialic acid is a fundamental component of the tumor microenvironment, modulates cell-cell and cell-extracellular matrix interactions and is associated with bad prognosis and clinical outcomes in different cancers. Capitalizing on the ability of boric acid to form cyclic esters with diols, in this work, we design self-assembled multi-micellar colloidal systems of an amphiphilic poly(vinyl alcohol)-g-poly(methyl methacrylate) copolymer surface-modified with boric acid for the active targeting of solid tumors that overexpress sialic acid. Nanoparticles display sizes in the 100-200 nm range and a spherical morphology, as determined by dynamic light scattering and high resolution-scanning electron microscopy, respectively. The uptake and anti-proliferative activity are assessed in 2D and 3D models of rhabdomyosarcoma in vitro. Surface boration increases the nanoparticle permeability and uptake, especially in rhabdomyosarcoma spheroids that overexpress sialic acid to a greater extent than 2D cultures. The biodistribution of non-borated and borated nanoparticles upon intravenous injection to a subcutaneous rhabdomyosarcoma murine xenograft model confirm a statistically significant increase in the intertumoral accumulation of the modified nanocarriers with respect to the unmodified counterparts and a sharp decrease in major clearance organs such as the liver. Overall, our results highlight the promise of these borated nanomaterials to actively target hypersialylated solid tumors.

Risk factors for lymph node metastasis of soft tissue sarcomas of the head, neck, and extremities, and the clinical significance of negative lymph node dissection

Background

This study sought to define the risk factors for lymph node metastasis (LNM) of soft tissue sarcomas (STS) of the head, neck, and extremities, and the clinical significance of negative lymph node dissection (NLND).

Methods

STS patient data in the Surveillance, Epidemiology, and End Results (SEER) database from 1988 to 2015 were extracted and pooled. Logistics regression analysis was used to identify risk factors for LNM, Cox proportional hazards and Fine–Grey’s models were used for survival analysis, and Propensity score matching analysis (PSM) was used to assess the impact of NLND on patient prognosis.

Results

A total of 3276 patients were enrolled in the study, of whom 283 (8.6%) developed LNM. Rhabdomyosarcoma had the highest rate of LNM (25.3%), followed by clear cell sarcoma (16.8%) and epithelioid sarcoma (12.4%), while leiomyosarcoma had the lowest rate of LNM (1.3%). Sex, tumor size, grade, histology, and site were significantly associated with LNM. For specific histologic subtypes of STS, NLND significantly improves overall survival (HR: 0.718, 95%CI 0.535–0.962; P = 0.026) and cancer-specific survival (HR: 0.699, 95%CI 0.506–0.967; P = 0.031) and reduces cancer-specific mortality (Gray’s test, P = 0.017). However, NLND did not improve overall survival (P = 0.46) or reduce cancer-specific mortality (Gray’s test, P = 0.772) of patients with leiomyosarcoma.

Conclusions

Histology is an independent risk factor for LNM in STS of the head, neck, and extremities. Prophylactic NLND treatment was necessary and had a clinical benefit for patients with STS who were at high risk for LNM but had no significant impact on the prognosis of patients with leiomyosarcoma.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13018-022-03050-3.

PET metabolic tumor volume as a new prognostic factor in childhood rhabdomyosarcoma

Purpose

Childhood RMS is a rare malignant disease in which evaluation of tumour spread at diagnosis is essential for therapeutic management. F-18 FDG-PET imaging is currently used for initial RMS disease staging.

Materials and methods

This multicentre retrospective study in six French university hospitals was designed to analyse the prognostic accuracy of MTV at diagnosis for patients with RMS between 1 January 2007 and 31 October 2017, for overall (OS) and progression-free survival (PFS). MTV was defined as the sum of the primitive tumour and the largest metastasis, where relevant, with a 40% threshold of the primary tumour SUVmax. Additional aims were to define the prognostic value of SUVmax, SUVpeak, and bone lysis at diagnosis.

Results

Participants were 101 patients with a median age of 7.4 years (IQR [4.0-12.5], 62 boys), with localized disease (35 cases), regional nodal spread (43 cases), or distant metastases (23). 44 patients had alveolar subtypes. In a univariate analysis, a MTV greater than 200 cm³ was associated with OS (HR = 3.47 [1.79;6.74], p<0.001) and PFS (HR = 3.03 [1.51;6.07], p = 0.002). SUVmax, SUVpeak, and bone lysis also influenced OS (respectively p = 0.005, p = 0.004 and p = 0.007) and PFS (p = 0.029, p = 0.019 and p = 0.015). In a multivariate analysis, a MTV greater than 200 cm³ was associated with OS (HR = 2.642 [1.272;5.486], p = 0.009) and PFS (HR = 2.707 [1.322;5.547], p = 0.006) after adjustment for confounding factors, including SUVmax, SUVpeak, and bone lysis.

Conclusion

A metabolic tumor volume greater than 200 cm³, SUVmax, SUVpeak, and bone lysis in the pre-treatment assessment were unfavourable for outcome.

Population-Based Survival Analysis of Patients With Limb Rhabdomyosarcoma and Metastasis at Diagnosis

Purpose: Given the poor prognosis and the relative rarity of patients diagnosed with limb rhabdomyosarcoma (LRMS) and metastasis at diagnosis, we performed this study to reveal distinctive clinical features and evaluated prognostic factors of this special population in order to provide appropriate treatment.

Patients and Methods: We carried out retrospective research of patients diagnosed with LRMS and metastasis from 1975 to 2016 using the Surveillance, Epidemiology, and End Results (SEER) program database. Survival curves were generated by applying the Kaplan–Meier method. In terms of evaluating and determining independent predictors of survival, we conducted univariate and multivariate survival analyses using the Cox proportional hazard regression model.

Results: This retrospective analysis contained a series of 245 patients with metastatic LRMS, with male predominance (male vs. female, 1.6:1). Nearly half of the patients were diagnosed with alveolar rhabdomyosarcoma (44.9%). According to the results of the univariate and multivariate analyses, younger age, tumor subtype, and radiotherapy were found to be significantly associated with improved overall survival (OS) and cause-specific survival (CSS).

Conclusions: Patients with LRMS and metastasis at diagnosis experienced a quite poor prognosis. Age at diagnosis, tumor subtype, and radiotherapy can help clinicians to better estimate the prognosis. This study indicated that local radiotherapy can provide a survival benefit.

Study of synergistic effects of Ficus Carica leaves extract mediated chemo-photodynamic therapy on rhabdomyosarcoma cells

BACKGROUND

Chemotherapy for rhabdomyosarcoma (RD) is effective, but it has critical side effects and unavoidable challenges. Photodynamic therapy (PDT) is an approach to treating cancer with relatively moderate side effects. Plant products are a rich source of polyphenols, which have potent antioxidant and anticancer activities. Therefore, their research has become an emerging field in recent decades.

PURPOSE

This work aimed to evaluate the potential of hydrophobic extract of Ficus Carica (FC) to determine whether FC in the presence of low dose chemo and Aluminium Phthalocyanine (Photosense®) mediated photodynamic therapy synergistically enhances the treatment efficacy of RD cells.

METHOD

FC with and without combination with individual therapeutic modalities like photosense mediated photodynamic therapy, chemotherapy, and their combinations were studied for cell viability and morphological changes in invitro RD cells. A semiconductor diode laser (630 nm) was used as a light source in PDT. The cytotoxic effect of FC on cell viability and cellular morphological changes were investigated by MTT reagent and a camera attached to an inverted visible light microscope. The effect of FC, followed by di-combination with low dose chemo (doxorubicin-HCl, and dacarbazine), Photosense® mediated PDT and chemo-Photosense® mediated PDT (tri-combination) at 630 nm diode laser and 10 J/cm² fluency were also investigated by MTT reagent. The combination index method is used to identify the synergistic effect of combination therapy by using CompuSyn software based on the Chou-Talalay method.

RESULTS

The dose-dependent effect of FC on cell viability and cellular morphological changes were observed in the RD cell line. It was found that the pre incubation of FC potentiated the anticancer effect as a neoadjuvant agent for doxorubicin-HCl and decarbazine based chemotherapy, Photosense® mediated PDT and chemo-PDT (tri-combination) with synergistic effect (CI<1).

CONCLUSION

These results suggest a possible thread that the low dose combination of the aforementioned therapeutic modalities in the presence of FC remarkably enhances the treatment efficacy of RD in comparison with a single-agent treatment modality. The proposed sequence of FC with chemo and PDT might present better therapeutic outcomes in RD therapies and may provide result for RD metastasis. FC may also be used in the application of phyto-PDT to cancer in the future.

Rhabdomyosarcoma Cells Produce Their Own Extracellular Matrix With Minimal Involvement of Cancer-Associated Fibroblasts: A Preliminary Study

BACKGROUND

The interplay between neoplastic cells and surrounding extracellular matrix (ECM) is one of the determinant elements for cancer growth. The remodeling of the ECM by cancer-associated fibroblasts (CAFs) shapes tumor microenvironment by depositing and digesting ECM proteins, hence promoting tumor growth and invasion. While for epithelial tumors CAFs are well characterized, little is known about the stroma composition of mesenchymal cancers, such as in rhabdomyosarcoma (RMS), the most common soft tissue sarcoma during childhood and adolescence. The aim of this work is to identify the importance of CAFs in specifying RMS microenvironment and the role of these stromal cells in RMS growth.

METHODS

We assessed in two dimensional (2D) and three dimensional (3D) systems the attraction between RMS cells and fibroblasts using epithelial colon cancer cell line as control. CAFs were studied in a xenogeneic mouse model of both tumor types and characterized in terms of fibroblast activation protein (FAP), mouse PDGFR expression, metalloproteases activation, and ECM gene and protein expression profiling.

RESULTS

In 2D model, the rate of interaction between stromal and malignant cells was significantly lower in RMS with respect to colon cancer. Particularly, in 3D system, RMS spheroids tended to dismantle the compact aggregate when grown on the layer of stromal cells. In vivo, despite the well-formed tumor mass, murine CAFs were found in low percentage in RMS xenogeneic samples.

CONCLUSIONS

Our findings support the evidence that, differently from epithelial cancers, RMS cells are directly involved in their own ECM remodeling, and less dependent on CAFs support for cancer cell growth.

MYBPC2 and MYL1 as Significant Gene Markers for Rhabdomyosarcoma

BACKGROUND

Rhabdomyosarcoma is the most common soft tissue tumor in children. Rhabdomyosarcoma commonly results in pain and bleeding caused by tumor compression and is prone to early metastasis and recurrence, which can seriously affect the therapeutic outcomes and long-term prognosis. Up to 37.7% of rhabdomyosarcomas may metastasize. Therefore, the molecular mechanisms underlying rhabdomyosarcoma must be explored to identify an effective target for its early diagnosis and specific treatment.

METHODS

A dataset of 18 rhabdomyosarcoma tissue samples and 6 healthy skeletal muscle samples was downloaded. Differentially expressed genes between rhabdomyosarcoma and healthy tissue samples were identified by GEO2R. Kyoto Encyclopedia of Genes and Genomes and gene ontology pathway enrichment analyses were performed. A protein-protein interaction network was constructed, and hub genes were identified. Expression and survival analyses of hub genes were performed. Additionally, 30 patients with rhabdomyosarcoma were recruited, and overall survival information and samples were collected. Reverse transcription quantitative real-time polymerase chain reaction assays were performed to verify the expression of MYBPC2 and MYL1 in rhabdomyosarcoma tumor tissues. The Kaplan-Meier method was used to explore overall survival based on our clinical data.

RESULTS

In total, 164 genes were up-regulated and 394 were down-regulated in rhabdomyosarcoma tumor tissues. Gene ontology analysis revealed that variations were predominantly enriched in the cell cycle, muscle contraction, muscle system processes, cytoskeleton, nucleotide binding, and cytoskeletal protein binding. The protein-protein interaction network revealed 3274 edges, and 441 nodes were constructed. Ten hub genes were identified; of these, MYBPC2 and MYL1 were significantly up-regulated in rhabdomyosarcoma. Compared with the healthy group, patients with rhabdomyosarcoma exhibiting high expression of MYBPC2 and MYL1 exhibited significantly worse overall survival.

CONCLUSIONS

We found differentially expressed genes between rhabdomyosarcoma and healthy tissue samples. MYBPC2 and MYL1 may be involved in the pathogenesis of rhabdomyosarcoma and therefore deserve further exploration.

Locoregional Control and Survival in Children, Adolescents, and Young Adults With Localized Head and Neck Alveolar Rhabdomyosarcoma-The French Experience

INTRODUCTION

The head and neck (HN) are the most frequent sites of pediatric rhabdomyosarcoma (RMS). Alveolar RMS (ARMS) represents ~20% of all RMS cases and frequently spread to lymph nodes (LNs). The aim was to report locoregional control, event-free survival (EFS), and overall survival (OS), according to clinical and pathological features, LN staging, and treatment modalities.

METHODS

The study included all patients prospectively enrolled in EpSSG RMS 2005 study under 21 years of age with localized HN ARMS and diagnosed between 2005 and 2016 in France. Medical data including imaging, surgical report, and radiation therapy planes were analyzed.

RESULTS

Forty-eight patients (median age 6 years; range 4 months-21 years), corresponding to 30 parameningeal and 18 non-parameningeal ARMS, were included. There were 33 boys (69%). Tumor locations included the following: orbit (n = 7) among which four cases had bone erosion, paranasal sinuses and nasal cavity (n = 16), deep facial spaces (n = 10), nasolabial fold (n = 8), and other non-parameningeal HN sites (n = 7). A fusion transcript of PAX3-FOXO1 or PAX7-FOXO1 was expressed in 33 of the 45 cases (73%) with molecular analysis. At diagnosis, 10 patients had primary resection of the primary tumor (PRPT) (none with microscopic complete resection) and 9 had LN staging. After induction chemotherapy, 26 patients (54%) had secondary resection of the primary tumor (SRPT) and 13 patients (27%) had cervical LN dissection. A total of 43 patients (90%) were treated with radiation therapy.With a median follow-up of 7 years (range 2-13 years), 5-year OS and EFS were 78% (95% CI, 63-88%) and 66% (95% CI, 51-78%), respectively. We observed 16 events (10 deaths): 4 local, 4 regional, 1 local and regional, and 7 metastatic. In univariate analysis, OS was only superior for patients under 10 years of age (p = 0.002), while FOXO1-negative ARMS, SRPT for parameningeal ARMS, and LN surgery were associated with significantly better EFS.

CONCLUSION

Our study confirms a better outcome for fusion-negative ARMS and ARMS in children under 10 years. Moreover, LN surgery and SRPT of parameningeal tumor may improve EFS of ARMS. Larger studies are needed to confirm our findings.

Characteristics and prognosis of embryonal rhabdomyosarcoma in children and adolescents: An analysis of 464 cases from the SEER database

IMPORTANCE

As the most common subtype of pediatric rhabdomyosarcoma (RMS), the prognosis of embryonal RMS has rarely been investigated solely.

OBJECTIVE

To perform a population-based study to characterize the prognosis of embryonal RMS in children and adolescents.

METHODS

Demographic and clinical features were retrospectively evaluated in selected patients with embryonal RMS registered in the Surveillance, Epidemiology, and End Results (SEER) program from 1988 to 2016. Survival curves were compared using the log-rank test. A multivariate Cox proportional hazards model was developed to assess the impact of each factor on the overall survival. A nomogram was constructed based on the results of Cox regression model.

RESULTS

A total of 464 patients were included in the analysis, among which 64.6% were male and 70.2% were white patients. About 38.6% and 26.3% of the patients were at 1-4 years and 5-9 years, respectively. Cox analysis showed that patients at age group 5-9 years had the lowest risk of mortality (hazard ratio [HR], 0.277; 95% confidential interval [CI], 0.123-0.620), compared with patients diagnosed at less than 1-year-old, and age group 1-4 years had the second-best prognosis. Patients having distant tumors had significantly higher mortality risk (HR, 4.842; 95% CI, 2.804-8.362) than the patients with localized tumor. Compared with receiving no surgery or radiotherapy, receiving any combination of surgery and radiotherapy would lower the risk of mortality significantly (for surgery without radiotherapy: HR, 0.418; for radiotherapy without surgery: HR, 0.405; and for surgery plus radiotherapy: HR, 0.410).

INTERPRETATION

Age, stage at diagnosis, and treatment received were found to be the most important predictors of the overall survival of pediatric embryonal RMS.

CT-Based Radiomics to Differentiate Pelvic Rhabdomyosarcoma From Yolk Sac Tumors in Children

Background

The purpose of this study was to investigate the role of CT radiomics features combined with a support vector machine (SVM) model in potentially differentiating pelvic rhabdomyosarcoma (RMS) from yolk sac tumors (YSTs) in children.

Methods

A total of 94 patients with RMS (n = 49) and YSTs (n = 45) were enrolled. Non-enhanced phase (NP), arterial phase (AP), and venous phase (VP) images were retrieved for analysis. The volumes of interest (VOIs) were constructed by segmenting tumor regions on CT images to extract radiomics features. Datasets were randomly divided into two sets including a training set and a test set. In the training set, the least absolute shrinkage and selection operator (LASSO) algorithm was used to screen out the optimal radiomics features that could distinguish RMS from YSTs, and the features were combined with the SVM algorithm to build the classifier model. In the testing set, the areas under the receiver operating characteristic (ROC) curves (AUCs), accuracy, specificity, and sensitivity of the model were calculated to evaluate its diagnostic performance. The clinical factors (including age, sex, tumor site, tumor volume, AFP level) were collected.

Results

In total, 1,321 features were extracted from the NP, AP, and VP images. The LASSO regression algorithm was used to screen out 23, 26, and 17 related features, respectively. Subsequently, to prevent model overfitting, the 10 features with optimal correlation coefficients were retained. The SVM classifier achieved good diagnostic performance. The AUCs of the NP, AP, and VP radiomics models were 0.937 (95% CI: 0.862, 0.978), 0.973 (95% CI: 0.913, 0.996), and 0.855 (95% CI: 0.762, 0.922) in the training set, respectively, which were confirmed in the test set by AUCs of 0.700 (95% CI: 0.328, 0.940), 0.800 (95% CI: 0.422, 0.979), and 0.750 (95% CI: 0.373, 0.962), respectively. The difference in sex, tumor volume, and AFP level were statistically significant (P < 0.05).

Conclusions

The CT-based radiomics model can be used to effectively distinguish RMS and YST, and combined with clinical features, which can improve diagnostic accuracy and increase the confidence of radiologists in the diagnosis of pelvic solid tumors in children.

Prognostic Factors in Patients with Rhabdomyosarcoma Using Competing-Risks Analysis: A Study of Cases in the SEER Database

Background

Rhabdomyosarcoma (RMS) is a rare malignant soft-tissue sarcoma characterized by a poor outcome and unclear prognostic factors. This study applied a competing-risks analysis using data from the Surveillance, Epidemiology, and End Results (SEER) database to RMS patients, with the aim of identifying more accurate prognostic factors.

Methods

Data of all patients with RMS during 1986–2015 were extracted from the SEER database. We used the competing-risks approach to calculate the cumulative incidence function (CIF) for death due to rhabdomyosarcoma (DTR) and death from other causes (DOC) at each time point. The Fine–Gray subdistribution proportional-hazards model was then applied in univariate and multivariate analyses to determine how the CIF differs between groups and to identify independent prognostic factors. The potential prognostic factors were analyzed using the competing-risks analysis methods in SAS and R statistical software.

Results

This study included 3399 patients with RMS. The 5-year cumulative incidence rates of DTR and DOC after an RMS diagnosis were 39.9% and 8.7%, respectively. The multivariate analysis indicated that age, year of diagnosis, race, primary site, historic stage, tumor size, histology subtype, and surgery status significantly affected the probability of DTR and were independent prognostic factors in patients with RMS. A nomogram model was constructed based on multivariate models for DTR and DOC. The performances of the two models were validated by calibration and discrimination, with C-index values of 0.758 and 0.670, respectively.

Conclusions

A prognostic nomogram model based on the competing-risks model has been established for predicting the probability of death in patients with RMS. This validated prognostic model may be useful when choosing treatment strategies and for predicting survival.

Genetic Syndromes Affecting Both Children and Adults: A Practical Guide to Imaging-based Diagnosis, Management, and Screening Recommendations for General Radiologists

Genetic syndromes are an infrequently encountered but challenging group of conditions for both pediatric and adult radiologists given the multitude of possible findings and important complications associated with these syndromes. This article reviews characteristic syndromic imaging features, as well as discussing important complications and screening recommendations for a selected group of clinically relevant genetic syndromes affecting both pediatric and adult populations.

Prognostic Value of Circulating IGFBP2 and Related Autoantibodies in Children with Metastatic Rhabdomyosarcomas

Insulin-like growth factor-binding protein 2 (IGFBP2) is a tumor-associated protein measurable in patients’ biopsies and blood samples. Increased IGFBP2 expression correlates with tumor severity in rhabdomyosarcoma (RMS). Thus, we examined the plasmatic IGFBP2 levels in 114 RMS patients and 15 healthy controls by ELISA assay in order to evaluate its value as a plasma biomarker for RMS. Additionally, we looked for the presence of a humoral response against IGBFP2 protein measurable by the production of anti-IGFBP2 autoantibodies. We demonstrated that both circulating IGFBP2 protein and autoantibodies were significantly higher in RMS patients with respect to controls and their combination showed a better discriminative capacity. IGFBP2 protein identified metastatic patients with worse event-free survival, whereas both IGFBP2 and anti-IGFBP2 antibodies negatively correlated with overall survival. Our study suggests that IGFBP2 and anti-IGFBP2 antibodies are useful for diagnostic and prognostic purposes, mainly as independent negative prognostic markers in metastatic patients. This is the first study that reports a specific humoral response in RMS plasma samples and proves the value of blood-based biomarkers in improving risk assessment and outcome of metastatic RMS patients.

Nodal metastases of soft tissue sarcomas: risk factors, imaging findings, and implications

Soft tissue sarcomas (STS) are malignancies derived from connective tissue, and regional lymph node metastasis (RLNM), while not common, is an important aspect of prognosis and treatment. Various risk factors, in particular the histological subtype, affect the likelihood of nodal involvement, which can be characterized by imaging features such as nodal dimension and morphology. Currently, surveillance and management vary by institution, as concrete societal guidelines have not been established. Common nodal status assessment strategies include physical exam, US CT, MRI, sentinel lymph node biopsy (SLNB) and radical lymphadenectomy. This article summarizes data regarding relevant risk factors of RLNM, imaging features, and any available data regarding surveillance recommendations.

Oropharyngeal Rhabdomyosarcoma with cranial nerve paralysis in a limited resource setting: a case report and review of literature

Rhabdomyosarcoma (RMS), a tumor of skeletal muscle origin, is the most common soft tissue sarcoma encountered in childhood and adolescence; it is primarily found in the head and neck region, it is relatively uncommon tumors of the oral cavity. Clinical signs depend on the exact location of the lesion in the oral cavity and its development. Authors reported the case of a 14-year-old patient who presented an oropharyngeal mass causing voice dysfunction, after two surgical operation the patient experimented two 2 recurrences of the lesion. The histopathological examination objectifies an oropharyngeal rhabdomyosarcoma. Immediate postoperative outcome was uneventful with improvement in the voice dysfunction and dysphagia one month after surgery. Complementary treatment (chemotherapy and radiotherapy) was not available and accessible to the patient. Twenty months (20) after surgery, the examination found a recurrence of the tumor with pulmonary metastases and neurological complications. Oropharyngeal rhabdomyosarcomas are rare. Their interest lies in the fact that they often affect children and adolescents. The prognosis remains unfavorable in our context, even for cases accessible to surgery since complementary treatment with chemotherapy and / or radiotherapy does not exist. The prognosis depends on tumor size, location, staging, age of patients and especially the quality of the management.

Small bowel metastasis from pulmonary rhabdomyosarcoma causing intussusception: a case report

Background

Rhabdomyosarcoma (RMS), especially primary pulmonary RMS, is an extremely rare type of soft tissue sarcoma in adults. Small bowel is an uncommon site for metastases.

Case presentation

This report described an unusual case of jejunum metastasis from primary pulmonary RMS causing intussusception in a 75-year-old man. The patient consulted for 2 weeks of continuous dyspnea. Chest computed tomography (CT) demonstrated a large mass involving the left lower lobe. Transthoracic biopsy confirmed the existence of pleomorphic RMS. Immunohistochemical studies showed positive findings about desmin and MyoD1. The results of gastroscopy, colonoscopy and abdominal CT were all negative. Positron emission tomography/CT demonstrated a fluorodeoxyglucose-reactive large lesion in the left lower lobe without metastatic lesions. The patient received synchronous chemoradiotherapy. After 9 months, the patient presented with intermittent upper abdominal pain with nausea and vomiting. CT showed small bowel dilatation secondary to intussusception. The patient subsequently received laparotomy, and the intussuscepted small bowel segment was resected. Histological examination revealed pleomorphic RMS involving the mucosa, submucosa, and muscular tissues.

Conclusions

RMS is highly aggressive and metastatic. The metastatic disease can rapidly progress to cause subsequent complications. The possibility of small bowel metastasis should be considered, although it is extremely rare.

MR Imaging of Pediatric Musculoskeletal Tumors:: Recent Advances and Clinical Applications

Pediatric musculoskeletal tumors comprise approximately 10% of childhood neoplasms, and MR imaging has been used as the imaging evaluation standard for these tumors. The role of MR imaging in these cases includes identification of tumor origin, tissue characterization, and definition of tumor extent and relationship to adjacent structures as well as therapeutic response in posttreatment surveillance. Technical advances have enabled quantitative evaluation of biochemical changes in tumors. This article reviews recent updates to MR imaging of pediatric musculoskeletal tumors, focusing on advanced MR imaging techniques and providing information on the relevant physics of these techniques, clinical applications, and pitfalls.

Pediatric Musculoskeletal Imaging: The Indications for and Applications of PET/Computed Tomography

The use of PET/computed tomography (CT) for the evaluation and management of children, adolescents, and young adults continues to expand. The principal tracer used is 18F-fluorodeoxyglucose and the principal indication is oncology, particularly musculoskeletal neoplasms. The purpose of this article is to review the common applications of PET/CT for imaging of musculoskeletal issues in pediatrics and to introduce the use of PET/CT for nononcologic issues, such as infectious/inflammatory disorders, and review the use of 18F-sodium fluoride in trauma and sports-related injuries.

A retrospective analysis of oral and maxillofacial pathology in a pediatric population from Rio de Janeiro-Brazil over a 75-year period

Background

The aim of this study was to analyze the distribution of oral and maxillofacial lesions affecting children and adolescents patients from a single oral pathology laboratory from Rio de Janeiro, Brazil.

Material and Methods

Oral and maxillofacial lesions biopsied in patients younger than 19-years were retrieved from the oral pathology files of the Department of Oral Diagnosis and Pathology, School of Dentistry, Federal University of Rio de Janeiro over a 75-year period (1942-2017). The clinical data and the diagnoses of each case were included in a Microsoft Excel® database, being classified into 13 categories according to the etiology. A descriptive analysis of the variables age, gender and final diagnosis was made.

Results

From 19.095 lesions diagnosed in this period, 2408 (12.61%) were from patients aged 0 to19 years, with a higher incidence in females in the second decade. Salivary gland pathology was the most common group of lesions (24.30%), followed by reactive lesions (16.82%) and odontogenic cysts (14.66%). Mucocele was the most common lesion (21.72%), followed by dentigerous cyst (6.48%) and fibrous hyperplasia (6.44%). Malignant lesions were observed in 1.12% of all cases with Burkitt lymphoma as the most frequent.

Conclusions

Our results were similar to previous studies and knowledge of these data may contribute to the understanding of oral lesions that most commonly affects children.

Key words:Pediatrics, children, pathology, oral lesions, oral cavity.