Update on rhabdomyosarcoma

The Other Site of Rhabdomyosarcoma

BACKGROUND

Rhabdomyosarcoma (RMS) is a rare malignant soft tissue sarcoma (STS), accounting for almost 50% of pediatric STSs. Due to its heterogeneity, RMS presents challenges in diagnosis and treatment, with prognosis varying depending on multiple factors. Tumors localized in the other site (OTH)-including the paraspinal, perianal, thoracic, abdominal, pelvic, and perineal regions-are generally classified as unfavorable. This study assesses the clinical features and prognoses of RMS in OTH locations depending on its site of origin.

METHODS

An explorative analysis of RMS cases from the SEER 17 database 2000-2020 was conducted. Patients of all ages with histologically confirmed RMS as primary malignant disease classified under OTH, were included. OTH was categorized in four granular site classifications. Overall survival (OS) and disease-specific survival (DSS) were analyzed using Kaplan-Meier estimators. Factors independently influencing survival, including a site classification model presented in this study, were identified through Cox regression analysis.

RESULTS

Out of 4168 patients with RMS, 990 cases of RMS with the OTH site met the inclusion criteria. The median age was 16 years. The predominant histological subtypes were embryonal (33.0%) and alveolar (25.5%). Most tumors were ≥ 5 cm (median 9 cm) and located primarily in the pelvic region (41.5%). The 3-, 5-, and 10-year OS rates were 45.4% ± 3.332 (95% CI), 40.7 ± 3.332, and 38.6% ± 3.332, respectively, while DSS rates were 43.3% ± 3.136 (95% CI), 38.3% ± 3.136, and 35.1% ± 3.332. In the multivariate analysis age, histological type, site in a granular categorization, stage, regional lymph node examination, and regional lymph node involvement (pathologically proven) were independently associated with survival. Through both univariate and multivariate analyses, an OTH favorable group could be established. The OTH favorable group consists of the anal region, gallbladder and biliary tract, and breast.

CONCLUSION

RMS in OTH shows significant differences in prognosis, putting the current categorization as unfavorable into question and making a more detailed classification necessary. Furthermore, pathological regional lymph node assessment is specifically in the OTH localization recommended.

A rare case of metastatic prostatic rhabdomyosarcoma in a young adult: Clinical challenges and therapeutic perspectives

Embryonal rhabdomyosarcoma of the prostate in adults is rare and often diagnosed at an advanced stage, with metastases. We report the case of a 23-year-old young adult presenting with low back pain and dysuria, whose imaging revealed a voluminous metastatic prostate mass. Biopsy confirmed embryonal rhabdomyosarcoma. Treatment was initiated with chemotherapy, resulting in significant regression of the tumour mass and metastases after 3 courses. Pediatric advances suggest improved survival with a multimodal approach, but its efficacy in adults requires further investigation.

Selective Targeting of Regulated Rhabdomyosarcoma Cells by Trinuclear Ruthenium(II)-Arene Complexes

The use of benzimidazole-based trinuclear ruthenium(II)-arene complexes (1-3) to selectively target the rare cancer rhabdomyosarcoma is reported. Preliminary cytotoxic evaluations of the ruthenium complexes in an eight-cancer cell line panel revealed enhanced, selective cytotoxicity toward rhabdomyosarcoma cells (RMS). The trinuclear complex 1 was noted to show superior short- and long-term cytotoxicity in RMS cell lines and enhanced selectivity relative to cisplatin. Remarkably, 1 inhibits the migration of metastatic RMS cells and maintains superior activity in a 3D multicellular spheroid model in comparison to that of the clinically used cisplatin. Mechanistic insights reveal that 1 effectively induces genomic DNA damage, initiates autophagy, and prompts the intrinsic and extrinsic apoptotic pathways in RMS cells. To the best of our knowledge, 1 is the first trinuclear ruthenium(II) arene complex to selectively kill RMS cells in 2D and 3D cell cultures.

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.

Alveolar Rhabdomyosarcoma of the Temporal Region with Metastatic Cervical Lymph Node

Introduction: Paediatric rhabdomyosarcoma most commonly occurs in the head and neck region. Its treatment is complex, including multi-drug chemotherapy, surgery and radiotherapy. Case report: Here, we report a case of alveolar rhabdomyosarcoma of the temporal region with a metastatic cervical lymph node, in a 15-year-old girl, and its management. The patient received ne-adjuvant chemotherapy, followed by surgery and post operative radiotherapy. Literature was also reviewed for the various treatment modalities for these rare tumours. Discussion: Rhabdomyosarcoma of the temporal region has rarely been reported in the literature. Due to the rarity of these tumours, there are difficulties in creating standardized therapeutic protocols. However, multimodality treatment, including chemotherapy, surgery and radiotherapy, has been shown to improve the overall survival rate.

Rhabdomyosarcoma: Current Therapy, Challenges, and Future Approaches to Treatment Strategies

Rhabdomyosarcoma is a rare cancer arising in skeletal muscle that typically impacts children and young adults. It is a worldwide challenge in child health as treatment outcomes for metastatic and recurrent disease still pose a major concern for both basic and clinical scientists. The treatment strategies for rhabdomyosarcoma include multi-agent chemotherapies after surgical resection with or without ionization radiotherapy. In this comprehensive review, we first provide a detailed clinical understanding of rhabdomyosarcoma including its classification and subtypes, diagnosis, and treatment strategies. Later, we focus on chemotherapy strategies for this childhood sarcoma and discuss the impact of three mechanisms that are involved in the chemotherapy response including apoptosis, macro-autophagy, and the unfolded protein response. Finally, we discuss in vivo mouse and zebrafish models and in vitro three-dimensional bioengineering models of rhabdomyosarcoma to screen future therapeutic approaches and promote muscle regeneration.

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.

INternational Soft Tissue saRcoma ConsorTium (INSTRuCT) consensus statement: Imaging recommendations for the management of rhabdomyosarcoma

Rhabdomyosarcoma is the most common soft-tissue neoplasm in the pediatric population. The survival of children with rhabdomyosarcoma has only marginally improved over the past 25 years and remains poor for those with metastatic disease. A significant challenge to advances in treatment of rhabdomyosarcoma is the relative rarity of this disease, necessitating years to complete clinical trials. Progress can be accelerated by international cooperation and sharing national experiences. This necessitates agreement on a common language to describe patient cohorts and consensus standards to guide diagnosis, treatment, and response assessment. These goals formed the premise for creating the INternational Soft Tissue saRcoma ConsorTium (INSTRuCT) in 2017. Multidisciplinary members of this consortium have since developed international consensus statements on the diagnosis, treatment, and management of pediatric soft-tissue sarcomas. Herein, members of the INSTRuCT Diagnostic Imaging Working Group present international consensus recommendations for imaging of patients with rhabdomyosarcoma at diagnosis, at staging, and during and after completion of therapy. The intent is to promote a standardized imaging approach to pediatric patients with this malignancy to create more-reliable comparisons of results of clinical trials internationally, thereby accelerating progress in managing rhabdomyosarcoma and improving survival.

Mesenteric embryonal rhabdomyosarcoma in an adolescent: a case report

Rhabdomyosarcoma (RMS) is a soft tissue sarcoma that histologically resembles embryonic skeletal muscle. It can occur anywhere in the body, including tissues devoid of skeletal muscles. RMS is a common malignancy in children, and it accounts for ˃50% of all soft tissue sarcomas in children. Embryonal rhabdomyosarcoma (ERMS) mostly affects children younger than 10 years of age. The head and neck area, the genitourinary tract and the retroperitoneum are described as the preferred anatomic sites for ERMS development. However, the mesentery location is extremely rare. We report a rare case of an ERMS occurring in the mesentery of a 17-year-old male.

18 F-FDG PET/CT of Alveolar Rhabdomyosarcoma of Prostate in a 17-Year-Old Boy

ABSTRACT

Rhabdomyosarcoma of the prostate is a rare malignancy that usually presents in childhood and adolescence with symptoms of bladder outlet obstruction. Serum prostate-specific antigen is usually normal, and 18 F-FDG PET/CT has a crucial role to rule out distant metastases. We present a case of alveolar rhabdomyosarcoma of the prostate in a 17-year-old boy.

A multi-disciplinary team approach to pediatric malignant mandibular tumors

OBJECTIVE

Mandibular tumors in the pediatric population are rare. These malignancies are variable in their histology, and combined with their rarity, has made it difficult to describe their clinical course, and treatment guidelines. The aim of this paper is to describe the experience of Boston Children's Hospital, a pediatric tertiary referral center, with treating malignant mandibular malignancies, as well as provide multi-disciplinary team approach in managing this clinical entity.

METHODS

A retrospective search was performed for mandibular malignancies in pediatric patients between 1995 and 2020 via the pathological database at Boston Children's Hospital. Only patients with malignant solid mandibular neoplasms were included, leaving 15 patients for final analysis.

RESULTS

The median age at presentation was 10.1 ± 10.3 years. Nine of 15 patients (60%) presented with jaw mass which was the most common clinical presentation. The most commonly identified histological diagnosis was rhabdomayosarcoma and osteosarcoma (n = 4, 26% each). A mandibulectomy was performed in 12 (80%) cases. Reconstruction of the mandible was performed using a fibular free flap in 6 (40%) cases, and a plate in 3 (20%) cases. Mean follow-up was 4.6 ± 4.9 years.

CONCLUSION

Malignant tumors most commonly present with a jaw mass, however asymptomatic and incidental presentations follow closely and pathologies can vary greatly. Surgical resection and reconstruction is often indicated, multidisciplinary tumor board review is required to determine when children are best treated with neo-/adjuvant treatment with chemo- and radiotherapy.

Cutaneous Metastasis of Alveolar Rhabdomyosarcoma in a Child

ABSTRACT

Rhabdomyosarcoma (RMS) is one of the most common soft tissue sarcomas in children. This lesion is classically included in the generic group of "small round blue cell tumors" along with other entities that share similar microscopic features. Although the head and neck region is a frequent site for primary tumors, cutaneous metastases of RMS involving this anatomical location are rare in the pediatric population. We report a case of a 12-year old girl previously diagnosed with a primary alveolar RMS involving the left maxillary sinus, presenting with a metastatic lesion on the skin of the left temple area. Along with a brief review of the previous case reports on the topic, we highlight the initial immunohistochemistry panel useful for diagnosing this tumor.

Anticancer bioactivity of zerumbone on pediatric rhabdomyosarcoma cells

PURPOSE

Natural products are generally regarded as safe and have been shown to mediate anticancer activities against a variety of cell types. Zerumbone is a natural cyclic sesquiterpene derived from the rhizome of Zingiber zerumbet, which has attracted extensive attention in the recent decade for anticancer activities. The present study investigates the in vitro effect of zerumbone on rhabdomyosarcoma cells.

METHODS

Two rhabdomyosarcoma cell lines (RD and RH30) were used as the model system. The growth inhibition of zerumbone was measured by MTT-assay, apoptosis via flow cytometry, gene expression by real-time PCR, the migration by transwell assay, and intracellular signaling by Western blotting.

RESULTS

Zerumbone shows anticancer effects on RD and RH30 cells in a dose-dependent manner via cell growth inhibition and induction of apoptosis. Exposure of RD and RH30 cells on zerumbone also resulted in a decrease of migration and downregulation of the hedgehog pathway.

CONCLUSIONS

Taken together, our study provided the first evidence that zerumbone imparted strong inhibitory and apoptotic effects on pediatric rhabdomyosarcoma cell lines and merit further investigation as a promising candidate for the anticancer therapy.

Adult Sinonasal Rhabdomyosarcoma With Spinal Metastasis: A Case Report and Review of the Literature

Rhabdomyosarcoma (RMS) is a malignant soft-tissue tumor mainly seen in the pediatric population. Here, we describe a case of an aggressive sinonasal RMS with distant metastasis in an adult patient. A 51-year-old male presented to the otolaryngology clinic with a unilateral painless neck mass and nasal obstruction. A flexible transnasal endoscope showed a huge fungating mass obstructing more than 80% of the right nasal cavity. A contrasted computed tomography (CT) scan of the paranasal sinuses showed an enhancing soft-tissue density mass involving the right nasal cavity. A biopsy revealed RMS, an embryonal variant. The patient responded well to chemoradiotherapy but later developed spinal metastasis and cord compression. He was admitted for palliative care but died due to cardiopulmonary arrest 10 months after diagnosis. A high index of clinical suspicion for malignancy is required in adult patients with unilateral nasal symptoms.

Mesenchymal Neoplasms of the Prostate and Seminal Vesicles: Spectrum of Disease with Radiologic-Pathologic Correlation

There is a wide spectrum of benign and malignant mesenchymal neoplasms of the prostate, which account for less than 1% of all prostatic tumors. These include distinctive tumors that arise from the specialized prostatic stroma and site-agnostic neoplasms such as smooth muscle tumors, fibrous or myofibroblastic neoplasms, neurogenic tumors, vascular tumors, and a plethora of sarcomas. Select tumors show classic sites of origin within the prostate. While stromal tumors of uncertain malignant potential (STUMPs) commonly involve the peripheral zone at the prostate base, leiomyomas typically originate from the central prostate toward the apex. Some "prostatic" neoplasms such as gastrointestinal stromal tumors, solitary fibrous tumor (SFT), paragangliomas, and neurogenic tumors arise primarily from periprostatic soft tissues. Most mesenchymal tumors of the prostate and seminal vesicles manifest as large tumors that cause nonspecific symptoms; prostate-specific antigen level is not typically elevated. Diverse mesenchymal neoplasms demonstrate characteristic histopathologic and immunocytochemical features and variable cross-sectional imaging findings. While leiomyoma and SFT typically display low signal intensity on T2-weighted images, synovial sarcomas commonly show hemorrhage. Diagnosis is difficult because of the rarity and lack of awareness of the tumors and the significant overlap in histopathologic features. Select tumors show characteristic genetic abnormalities that allow the diagnosis to be established. For example, more than 90% of SFTs are characterized by a unique NAB2-STAT6 gene fusion, and more than 95% of synovial sarcomas are associated with a distinctive SYT-SSX chimeric transcript. Accurate diagnosis is imperative for optimal management owing to markedly different tumor biology as well as attendant therapeutic and prognostic implications. While STUMPs commonly recur, sarcomas typically charter an aggressive course with poor prognosis. Online supplemental material is available for this article. ^©RSNA, 2022.

Pediatric Sinonasal Rhabdomyosarcoma Presented as Squint: A Case Report and Literature Review

Rhabdomyosarcoma (RMS) is the most common soft-tissue tumor in children, frequently affecting the nose, nasopharynx, and paranasal sinuses. RMS of this sinonasal region manifests with non-specific nasal symptoms of allergic rhinitis, sinusitis, or upper airway infection. Associated ocular symptoms are rare. We describe a young girl who presented with acute onset squint secondary to sinonasal RMS. Imaging showed an aggressive sinonasal tumor with oropharyngeal, intraorbital, and intracranial extension. Histopathological findings were consistent with a diagnosis of rhabdomyosarcoma, embryonal type. The patient deteriorated rapidly due to disease complications. We provide a literature review of pediatric sinonasal RMS with various manifestations.

Surgical Management of Rhabdomyosarcoma of the Nasal Cavity and Paranasal Sinuses: Analysis of Operative Indications, Settings, and Outcomes

Objectives The role of surgery in management of sinonasal rhabdomyosarcoma (SNRMS) has traditionally been limited, owing to anatomic and technological challenges and the established role of systemic therapy. Herein, we report our institutional experience with surgical management of SNRMS, with a particular focus on operative approaches, extent and outcomes.

Design This study is a retrospective cohort study.

Setting This study was conducted at a single-institution, academic center.

Participants Patients of any age with histologically confirmed RMS of the nasal cavity, maxillary, ethmoid, frontal, or sphenoid sinus, nasolacrimal duct, or nasopharynx presenting between 1994 and 2020 were included in this study.

Main Outcome Measures Demographics, tumor characteristics, operative settings, complications and recurrence, and survival outcomes were the primary outcomes of this study.

Results Our study cohort comprised of 29 patients (mean [range] age: 27.0 [3.1–65.7], n = 12 [41%] female). Tumors of the nasal cavity (n = 10, 35%) and ethmoid sinuses (n = 10, 35%) and those with alveolar histology (n = 21, 72%) predominated. Patients who had surgery as part of their treatment (n = 13, 45%) had improved distant metastasis-free survival (DMFS) overall (hazard ratio [HR]: 0.32, 95% CI: 0.11, 0.98, p = 0.05) as compared with those who did not have surgery. Surgical approaches included open (n = 7), endoscopic (n = 4), and combined (n = 2). Eight of these 13 patients (62%) had an R0 resection. Additionally, surgical salvage of recurrent disease was employed in five patients (17%).

Conclusion SNRMS is an aggressive malignancy with a high rate of recurrence and spread requiring a multidisciplinary approach for optimal outcomes. Our data supports an expanding role for surgery for SNRMS given its feasibility, tolerability, and potential to improve outcomes.

The Role of BiP and the IRE1α-XBP1 Axis in Rhabdomyosarcoma Pathology

BACKGROUND

Rhabdomyosarcoma (RMS) is the most common soft-tissue sarcoma in children, and is associated with a poor prognosis in patients presenting with recurrent or metastatic disease. The unfolded protein response (UPR) plays pivotal roles in tumor development and resistance to therapy, including RMS.

METHODS

In this study, we used immunohistochemistry and a tissue microarray (TMA) on human RMS and normal skeletal muscle to evaluate the expression of key UPR proteins (GRP78/BiP, IRE1α and cytosolic/nuclear XBP1 (spliced XBP1-sXBP1)) in the four main RMS subtypes: alveolar (ARMS), embryonal (ERMS), pleomorphic (PRMS) and sclerosing/spindle cell (SRMS) RMS. We also investigated the correlation of these proteins with the risk of RMS and several clinicopathological indices, such as lymph node involvement, distant metastasis, tumor stage and tumor scores.

RESULTS

Our results revealed that the expression of BiP, sXBP1, and IRE1α, but not cytosolic XBP1, are significantly associated with RMS (BiP and sXBP1 p-value = 0.0001, IRE1 p-value = 0.001) in all of the studied types of RMS tumors (n = 192) compared to normal skeletal muscle tissues (n = 16). In addition, significant correlations of BiP with the lymph node score (p = 0.05), and of IRE1α (p value = 0.004), cytosolic XBP1 (p = 0.001) and sXBP1 (p value = 0.001) with the stage score were observed. At the subtype level, BiP and sXBP1 expression were significantly associated with all subtypes of RMS, whereas IRE1α was associated with ARMS, PRMS and ERMS, and cytosolic XBP1 expression was associated with ARMS and SRMS. Importantly, the expression levels of IRE1α and sXBP1 were more pronounced in ARMS than in any of the other subtypes. The results also showed correlations of BiP with the lymph node score in ARMS (p value = 0.05), and of sXBP1 with the tumor score in PRMS (p value = 0.002).

CONCLUSIONS

In summary, this study demonstrates that the overall UPR is upregulated and, more specifically, that the IRE1/sXBP1 axis is active in RMS. The subtype and stage-specific dependency on the UPR machinery in RMS may open new avenues for the development of novel targeted therapeutic strategies and the identification of specific tumor markers in this rare but deadly childhood and young-adult disease.

[Paratesticular rhabdomyosarcoma: about a case and literature review]

Nous rapportons une observation d´un rhabdomyosarcome embryonnaire paratesticulaire chez un adulte jeune et soulignons le caractère inhabituel de cette forme histologique dans cette tranche d´âge, l´évolution rapide de la lésion ainsi que les difficultés de prise en charge de ce type de tumeurs dans notre contexte.

Single-cell transcriptional profiling reveals the heterogeneity in embryonal rhabdomyosarcoma

ABSTRACT

Rhabdomyosarcoma is the most common soft tissue sarcoma in children, and embryonal rhabdomyosarcoma is the most typical type of rhabdomyosarcoma. The heterogeneity, etiology, and origin of embryonal rhabdomyosarcoma remain unknown.After obtaining the gene expression data of every cell in the tumor tissue by single-cell RNA sequencing, we used the Seurat package in R studio for quality control, analysis, and exploration of the data. All cells are divided into tumor cells and non-tumor cells, and we chose tumor cells by marker genes. Then, we repeated the process to cluster the tumor cells and divided the subgroups by their differentially expressed genes and gene ontology/Kyoto Encyclopedia of Genes and Genomes analysis. Additionally, Monocle 2 was used for pseudo-time analysis to obtain the evolution trajectory of cells in tumor tissues.Tumor cells were divided into 5 subgroups according to their functions, which were characterized by high proliferation, sensing and adaptation to oxygen availability, enhanced epigenetic modification, enhanced nucleoside phosphonic acid metabolism, and ossification. Evolution trajectory of cells in tumor tissues is obtained.We used pseudo-time analysis to distinguish between mesenchymal stem cells and fibroblasts, proved that embryonal rhabdomyosarcoma in the pelvic originated from skeletal muscle progenitor cells, showed the evolutionary trajectory of embryonal rhabdomyosarcoma, and improved the method of evaluating the degree of malignancy of embryonal rhabdomyosarcoma.

DWI and IVIM Imaging in a Murine Model of Rhabdomyosarcoma: Correlations with Quantitative Histopathologic Features

BACKGROUND

High cellularity and abnormal interstitial structures are some of the unfavorable factors that affect the treatment outcomes and survival of rhabdomyosarcoma (RMS) patients.

PURPOSE

To explore the correlation between diffusion-weighted imaging (DWI) and intravoxel incoherent motion (IVIM) with quantitative histopathologic features in a murine model of RMS.

STUDY TYPE

Prospective.

ANIMAL MODEL

Murine model of RMS (31 female BALB/c nude mice).

FIELD STRENGTH/SEQUENCE

3.0 T; fast spin-echo (FSE) T1-weighted imaging, fast relaxation fast spin-echo (FRFSE) T2-weighted imaging, DWI PROPELLER FSE imaging sequence, and IVIM echo planar imaging sequence; 10 different b-values (0, 50, 100, 150, 200, 400, 600, 800, 1000, and 1200 s/mm² ).

ASSESSMENT

Magnetic resonance imaging (MRI) was performed after 30-45 days of implantation. The following MRI parameters were calculated: apparent diffusion coefficient (ADC), pure diffusion coefficient (D), pseudo-diffusion coefficient (D*), and perfusion fraction (f). Histopathologic features, which contained nuclear, cytoplasmic, and stromal fractions, and the nuclear-to-cytoplasmic ratio within the tumor were measured using image-based segmentation.

STATISTICAL TESTS

Pearson's correlation, multiple linear regression analysis, and receiver operating characteristic curve analysis were performed. A P < 0.05 was considered statistically significant.

RESULTS

The ADC value showed moderate negative correlation with nuclear fraction (r = -0.540), and moderate positive correlation with stroma fraction (r = 0.474). The D value showed moderate negative correlation with nuclear fraction (r = -0.491), and moderate positive correlation with stroma fraction (r = 0.421). The f value showed a moderate negative correlation with stroma fraction (r = -0.423). The D value showed the best diagnostic ability. The optimal cut-off D value of 0.460 was associated with 77.8% sensitivity and 68.2% specificity (area under the curve, 0.747).

DATA CONCLUSION

The ADC, D, and f values obtained from DWI and IVIM images showed moderate correlation with the quantitative histopathologic features in a murine model of RMS.

LEVEL OF EVIDENCE

1 TECHNICAL EFFICACY STAGE: 3.

Management of Rhabdomyosarcoma in Pediatric Patients

Rhabdomyosarcoma is the commonest soft tissue sarcoma in children. Clinicians need vigilance to recognize the different signs and symptoms this tumor can present with because of variable sites of origin. Diagnosis requires a safe biopsy that obtains sufficient tissue for pathologic, genetic, and biological characterization of the tumor. Treatment depends on accurate staging with imaging and surgical sampling of draining lymph nodes. A multidisciplinary team assigns patients to risk-based therapy. Patients require chemotherapy and usually a combination of complex, site-specific surgery and/or radiotherapy. Outcomes for localized rhabdomyosarcoma continue to improve but new treatments are required for metastatic and relapsed disease.

Embryonal rhabdomyosarcoma of breast, pleura, and retroperitoneum diagnosed from pleural fluid cytology

Embryonal rhabdomyosarcoma (ERMS) is a malignant small blue round cell tumor which is commonly seen in head and neck region. Breast and pleural involvement are uncommon. Rhabdomyosarcoma has been rarely reported in the body fluids like ascitic, pleural, and cerebrospinal fluid. In this article, we report an interesting case of ERMS which had deceptive small blue round cells in pleural fluid. The cytomorphological features along with a panel of immunocytochemical markers helped in arriving at the definite diagnosis. Later, biopsy from the breast lump and retroperitoneal mass also revealed the same tumor. This case is reported since it is rare to find sarcoma cells in pleural fluid and highlight the diagnostic difficulties faced during interpretation.

Pediatric laryngeal sarcoma: Systematic review and pooled analysis

BACKGROUND

Sarcomas are a rare, diverse tumor class of mesenchymal origin affecting all age groups. Survival after diagnosis is influenced by disease site. To date, there are no analyses evaluating treatment of pediatric sarcoma within the larynx specifically.

METHODS

A structured literature review following PRISMA guidelines was preformed to identify case reports of pediatric (age 17 and younger) laryngeal sarcoma.

RESULTS

Twenty-nine case reports documenting 37 pediatric patients diagnosed with sarcoma in the larynx were identified since 1980. The majority of patients were male (79.4%). The most common histological subtypes were rhabdomyosarcoma (69.4%) and synovial sarcoma (19.4%). The supraglottis was the most common site of disease (62.1%) among laryngeal subsites. Only two patients were known to have succumbed to their disease. Overall survival was not statistically impacted by primary site of tumor, treatment strategy, histology or gender.

CONCLUSIONS

Soft tissue sarcoma is rarely found in the pediatric larynx. Patient and tumor characteristics studied were not shown to affect outcomes. Increased documenting of high-quality case reports is needed to advance understanding of this disease.

Update on pediatric rhabdomyosarcoma: A report from the APSA Cancer Committee

BACKGROUND/PURPOSE

Rhabdomyosarcoma is the most common soft tissue sarcoma in children and young adults and requires multimodality treatment. The purpose of this review is to present an update on risk stratification as well as surgical and medical management strategies in pediatric rhabdomyosarcoma.

METHODS

A comprehensive review of the current literature on pediatric rhabdomyosarcoma, including the most recent Children's Oncology Group studies and several international collaboratives, was performed by the authors and key findings were summarized in the manuscript.

RESULTS

FOXO1 fusion status is a stronger prognostic factor than histology and is now used for risk stratification in treatment protocols. For assessment of regional nodal involvement, FDG-PET-CT shows poor sensitivity and specificity to detect histologically confirmed nodal metastasis. Thus, surgical assessment of regional lymph nodes is required for rhabdomyosarcoma of the extremities or trunk as well as paratesticular rhabdomyosarcoma in patients ≥10 years of age, although adherence to surgical guidelines remains poor. Hemiscrotectomy performed for scrotal violation in paratesticular rhabdomyosarcoma has not shown an improvement in event free survival and is not recommended.

CONCLUSIONS

Surgical and medical treatment strategies for rhabdomyosarcoma in children continue to evolve. This review provides current evidence-based treatment standards with an emphasis on surgical care.

TYPE OF STUDY

Review.

LEVEL OF EVIDENCE

Level IV.

Intracranial Rhabdomyosarcoma of the Cerebellopontine Angle in a 6-year-old Child: A Case Report

Rhabdomyosarcoma (RMS) is the most common soft-tissue malignancy in children under 15 years of age. Approximately, 35% of RMS cases originate from the head and neck region. Among various sites in the head and neck region, intracranial extension is more likely to occur with parameningeal tumors, which is also considered an unfavorable prognostic factor in children with RMS. About 20% of RMS occurs in a parameningeal site. Intracranial RMS are rare tumors that usually arise from parameningeal sites or metastasis from an extracranial site. Primary intracranial types are even rarer, with only 50 reported cases of primary intracranial RMS in the literature.

Hereby, we report the case of a 6-year-old boy who presented with clinical and radiologic features of a cerebellopontine angle lesion, which turned out to be a RMS.

Case Report of a Local Recurrence of Spindle Cell Embryonal Rhabdomyosarcoma

INTRODUCTION

Rhabdomyosarcoma (RMS) is the most common soft tissue sarcoma in children and adolescents. Spindle cell RMS is a rare variant of embryonal RMS that has a predilection for young males.

AIM

We are presenting here a case of a local recurrence of an embryonal variant of the spindle cell RMS in a 19-year-old male.

CASE REPORT

In this report it is described the study of patient with local recurrence of spindle cell embryonal RMS of the left testis after left orchiectomy and adjuvant chemotherapy. Computed tomography of the abdomen was used to evaluate the tumor. The recurrent mass was about 7,5cm and the patient was operated and discharged after 6 days in a good condition. Six months after the operation the patient had a new recurrence of RMS in the left retroperitoneal space.

CONCLUSION

RMS is a malignant tumor of mesenchymal origin that is treated by a combination of surgery, chemotherapy, and radiation. However, up to one-third of patients experience recurrence.

Patterns of failure and toxicity profile following proton beam therapy for pediatric bladder and prostate rhabdomyosarcoma

PURPOSE/OBJECTIVE(S)

Bladder and prostate are unfavorable sites for rhabdomyosarcoma (B/P-RMS), and represent a challenging location for radiotherapy.

MATERIALS/METHODS

Nineteen patients with B/P-RMS were enrolled on a prospective registry protocol (2008-2017) and treated with chemotherapy, proton beam therapy (PBT), and surgical resection (n = 8; 42%). Emphasis was given to treatment technique, disease-related outcomes, and toxicity associated with PBT.

RESULTS

The majority of patients had bladder RMS (74%) of embryonal histology (95%), Group III (68%), and intermediate-risk disease by Children's Oncology Group (COG) risk stratification (89%). Seven patients (37%) had primary tumors >5 cm in size. All patients were treated according to COG protocols. With a median follow-up of 66.2 months, 5-year overall survival (OS) and progression-free survival (PFS) were 76%. Four patients (21%) experienced disease relapse, all presenting with local failure. The 5-year local control (LC) rate was 76%. Tumor size predicted LC, with 5-year LC for patients with >5 cm tumors being 43% versus 100% for those with ≤5 cm tumors (P = .006). Univariate analysis demonstrated an effect of tumor size on OS (tumor >5 cm, hazard ratio [HR] 17.7, P = .049) and PFS (HR 17.7, P = .049). Acute grade 2 toxicity was observed in two patients (11%, transient proctitis). Late grade 2+ toxicity was observed in three patients (16%; n = 1 grade 2 skeletal deformity; n = 3 transient grade 2 urinary incontinence; one patient experienced both).

CONCLUSIONS

PBT for B/P-RMS affords promising disease-related outcomes with an acceptable toxicity profile. Higher local failure rates were observed for larger tumors, supporting dose-escalation components of ongoing RMS clinical trials.

Epidemiology, Incidence, and Survival of Rhabdomyosarcoma Subtypes: SEER and ICES Database Analysis

Rhabdomyosarcoma is the most common soft-tissue sarcoma in children and adolescents and accounts for 3% of all pediatric tumors. Subtypes include alveolar, spindle cell, embryonal, mixed-type, pleomorphic, and rhabdomyosarcoma with ganglionic differentiation. The National Cancer Institute's Surveillance, Epidemiology, and End Results (SEER) database was queried for patients diagnosed with any type of rhabdomyosarcoma between 1973 and 2014. Patient demographics, tumor characteristics, and incidence were studied with χ² analysis. Survival was modeled with Kaplan-Meier survival curves and Cox proportional hazards models were used to assess the effect of age and gender on survival. Pleomorphic subtype had higher grade and larger sized tumors compared to other subtypes (p < 0.05). Pleomorphic and alveolar rhabdomyosarcoma had the worst overall survival with a 26.6% and 28.9% 5-year survival, respectively. Embryonal rhabdomyosarcoma had the highest 5-year survival rate (73.9%). Tumor size was negatively correlated with survival months, indicating patients with larger tumors had shorter survival times (p < 0.05). Presence of higher-grade tumors and metastatic disease at presentation were negatively correlated with survival months (p < 0.05). No significant differences in the survival were found between gender or race between all of the subtypes (p > 0.05). This study highlights key differences in the demographic and survival rates of the different types of rhabdomyosarcoma that can be used for more tailored patient counseling. We also demonstrate that large, population-level databases provide sufficient data that can be used in the analysis of rare tumors. © 2019 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 37:2226-2230, 2019.

Rhabdomyosarcoma of the Adult Prostate: A Case Report With Complete Molecular Profile

Primary rhabdomyosarcoma of the adult prostate is rare and associated with an aggressive clinical course. Given the limited number of cases reported about the prostate, little is known about the impact of molecular mutations on tumor biology and prognosis in adults. In this article, we present a case of primary embryonal rhabdomyosarcoma of the adult prostate with a complete molecular mutational profile of the tumor.

[Paratesticular rhabdomyosarcoma: a case report]

Le rhabdomyosarcome (RMS) para-testiculaire est une tumeur rare. Le traitement doit être multimodal et fait appel à la chirurgie, à la chimiothérapie et à la radiothérapie. À la lumière de cette observation et d'une revue de la littérature, les auteurs discuteront les modalités diagnostiques et thérapeutiques.

The palladacycle complex AJ-5 induces apoptotic cell death while reducing autophagic flux in rhabdomyosarcoma cells

Rhabdomyosarcoma (RMS) forms in skeletal muscle and is the most common soft tissue sarcoma in children and adolescents. Current treatment is associated with debilitating side effects and treatment outcomes for patients with metastatic disease are dismal. Recently, a novel binuclear palladacycle, AJ-5, was shown to exert potent cytotoxicity in melanoma and breast cancer and to present with negligible adverse effects in mice. This study investigates the anti-cancer activity of AJ-5 in alveolar and embryonal RMS. IC50 values of ≤ 0.2 µM were determined for AJ-5 and it displayed a favourable selectivity index of >2. Clonogenic and migration assays showed that AJ-5 inhibited the ability of RMS cells to survive and migrate, respectively. Western blotting revealed that AJ-5 induced levels of key DNA damage response proteins (γH2AX, p-ATM and p-Chk2) and the p38/MAPK stress pathway. This correlated with an upregulation of p21 and a G1 cell cycle arrest. Annexin V-FITC/propidium iodide staining revealed that AJ-5 induced apoptosis and necrosis. Apoptosis was confirmed by the detection of cleaved PARP and increased levels and activity of cleaved caspases-3, -7, -8 and -9. Furthermore, AJ-5 reduced autophagic flux as shown by reduced LC3II accumulation in the presence of bafilomycin A1 and a significant reduction in autophagosome flux J. Finally, pharmacokinetic studies in mice show that AJ-5 has a promising half-life and that its volume of distribution is high, its clearance low and its intraperitoneal absorption is good. Together these findings suggest that AJ-5 may be an effective chemotherapeutic with a desirable mechanism of action for treating drug-resistant and advanced sarcomas.

Pediatric Robotic Prostatectomy and Pelvic Lymphadenectomy for Embryonal Rhabdomyosarcoma

We present the first published case of a pediatric robot-assisted prostatectomy and pelvic lymphadenectomy for refractory prostatic embryonal rhabdomyosarcoma. The patient is a 7-year-old male who had been treated with 3 cycles of chemotherapy and radiation, who underwent prostatectomy and lymphadenectomy for a recurrent mass. Surgery was uncomplicated and yielded negative surgical margins. We highlight the surgical technique and feasibility of utilizing robotic surgery for pediatric prostatectomy.

Current Treatment of Pediatric Bladder and Prostate Rhabdomyosarcoma

PURPOSE OF REVIEW

Rhabdomyosarcoma (RMS) is the most common sarcoma diagnosed in the first 20 years of life; bladder/prostate (BP) RMS accounts for 5% of all cases. Through efforts from multiple cooperative study groups, survival has improved significantly. This article aims to review the complex RMS classification system and treatment of BP RMS, with a focus on developing aspects of treatment.

RECENT FINDINGS

Recent advancements in technology are responsible for most of the progress in RMS treatment. PET-CT scanning has been shown to be superior to conventional metastatic workup. The use of proton beam therapy and brachytherapy to reduce the side effects of radiation is also showing promise. All cooperative oncology groups agree on surgical biopsy for diagnosis and staging of BP RMS. Patients are then grouped and risk classified before receiving chemotherapy. Regardless of local control strategy, oncologic outcomes appear to be similar for BP RMS. Alternative treatment strategies, which remain unproven, include brachytherapy and proton therapy.

Pediatric soft tissue sarcoma of the limbs: clinical outcome of 97 patients

PURPOSE

Soft tissue sarcomas (STS) of the extremities in children are a heterogeneous group of tumors with a very different prognosis for which optimal treatment remains controversial.

PATIENTS AND METHODS

We retrospectively evaluated 97 patients younger than 15 years old affected by limb soft tissue sarcomas. All cases were histologically revised, and tumor grade was assessed according to the FNLCC system. Thirty-two were rhabdomyosarcoma (RMS) and 65 non-rhabdomyosarcoma (NRMSTS); among these, 40 (61.5%) were grade 3 according to FNLCC classification. Overall survival, local recurrence and distant metastasis were analyzed.

RESULTS

Overall survival was 77.8% at 5 years and 69.7% at 10 years. Among grade 3 tumors, RMS had a worse prognosis over NRSTS. Similarly, tumors larger than 5 cm had a worse prognosis compared to smaller ones. Local recurrence-free survival was 90.7% at 5 years and 87.1% at 10 years with a better local control in grade 3 NRSTS over RMS and in tumors smaller than 2 cm.

CONCLUSION

Children affected by extremities RMS were confirmed to have the worst prognosis, in particular in case of metastasis at presentation. Differently from adult patients, hand and feet locations are frequent site for STS and 2 cm diameter should be taken as cut off for higher risk of LR. Similarly to adulthood STS, grading correlates with prognosis in NRSTS. The identification of prognostic variables should enable risk-adapted therapies to be planned.

Minimally Invasive Approach for Resection of Parameningeal Rhabdomyosarcoma

Background  About one-third of rhabdomyosarcomas arise in the head and neck, with parameningeal primaries accounting for half of these. Principles of management involve chemotherapy, radiation, or both, in addition to surgical biopsy, debulking, and complete or near-complete resection. In the head and neck, diagnostic biopsies have historically been performed without attempt at resection due to proximity to critical structures and cosmetic considerations. Methods  Retrospective chart review of three cases of rhabdomyosarcoma at the cranial base managed through minimally invasive endoscopic surgical resection and adjuvant therapy. Results  Three patients were identified as having undergone endoscopic surgical debulking or margin-negative resection of a rhabdomyosarcoma of the cranial base. Two of three patients had complete resection based on intraoperative margin control. All three patients underwent adjuvant therapy within 1 month of diagnosis. Follow-up time ranged from 5 months to 3 years with all patients disease-free at last follow-up. Conclusion  Skull base surgeons should routinely be involved in multidisciplinary treatment planning for parameningeal rhabdomyosarcomas, as surgical options have evolved to allow for potential endoscopic resection with low morbidity and no or minimal delay in additional treatment options.

A rare case of embryonal rhabdomyosarcoma of the parapharyngeal space

A 24-year-old man was admitted to our Otolaryngology Department following a head and neck CT scan performed for cranial trauma that showed a bulky neoformation in the right parapharyngeal space. Magnetic resonance imaging confirmed the presence of an oval formation with sharp margins and colliquative areas of necrosis involving the right parapharyngeal space. The mass was completely excised by a latero-cervical approach. Based on histological features and immunohistochemical analysis, a diagnosis of embryonal rhabdomyosarcoma of the parapharyngeal space was made. The incidental detection at this site of an embryonal rhabdomyosarcoma has never been reported in adult males.

Clinical Study on Female Genital Tract Rhabdomyosarcoma in Childhood: Changes During 20 Years in One Center

Objective

Rhabdomyosarcoma (RMS) is a rare tumor in girls. We intend to analyze the clinical feature, therapeutic effect, and prognosis of pediatric and adolescent RMS of the female genitourinary tract.

Methods

Pediatric or adolescent patients with female genital tract RMS in 1 tertiary hospital from 1995 to 2015 were retrospectively reviewed. The medical records were collected, including general information, tumor primary site, stage, histology, treatments, adverse effects, and survival outcomes.

Results

There were 8 girls with genital tract tumor in 403 patients with RMS during 20 years in 1 hospital: 5 originated in the vagina, 2 in the cervix, and 1 in the pelvis. Except for the patient with pelvic RMS who was diagnosed after acute abdominal pain, all the other patients presented with polypoid masses protruding from the vagina accompanied by mucosanguineous discharge. Mean age of patients at diagnosis was 5.4 years (8 months-14 years). Patients were categorized by using clinical group and TNM classification of malignant tumours staging system, 7 with stage I and 1 with stage II; none of them were classified to a higher stage. Histologically, all RMS were embryonal tumors with 3 botryoid variants. Patients were treated with surgery and adjuvant chemotherapy during which 6 patients developed fourth degree myelosuppression. All patients achieved complete remission. Two patients with vaginal RMS and the patient with pelvic RMS experienced tumor relapse and 2 patients died.

Conclusions

Rhabdomyosarcoma is a rare malignant sarcoma with a higher incidence in children and adolescents. Tumor sites are strongly associated with age at diagnosis. After combined therapy with local excision and chemotherapy, most patients can achieve a good prognosis. The prognosis is highly correlated with tumor site and histologic type.

Mixed Botryoid and Spindle Cell Bladder Rhabdomyosarcoma: An Outstanding Pediatric Case

We report a case of a 3-year-old North African child, initially assessed for nonspecific urinary symptoms such as haematuria and burning urination. The ultrasound evaluation showed a vegetating mass occupying the lumen with weak vascular signs at the Colour-Doppler evaluation. An explorative cystoscopy was performed and it revealed a nonbleeding lesion, white in colour, pedunculated, projecting into the lumen, and associated with a brown satellite formation. Histological examination showed a mixed Botryoid and Spindle Cell Rhabdomyosarcoma. This mixed histology has not been described before and no statistical data are reported in literature so far. Despite the Embryonal Rhabdomyosarcoma variant being the most common, the association characterized by two histological Rhabdomyosarcoma subtypes such as Botryoid and Spindle Cell is rarely observed and it is important to get an accurate histological diagnosis in order to immediately start the correct treatment protocol.

Outcomes of chest wall resections in pediatric sarcoma patients

PURPOSE

Chest wall tumors in pediatric patients are rare. This study evaluates outcomes in pediatric patients who have undergone chest wall resections secondary to sarcomas.

METHODS

A retrospective review was performed for patients <19years old who underwent chest wall resections for sarcoma 1999-2014 at the University of Texas MD Anderson Cancer Center.

RESULTS

Of 44 patients, Ewing's sarcoma (n=18) and osteosarcoma (n=16) were most common. Other sarcomas included synovial sarcoma, chondrosarcoma, and rhabdomyosarcoma. Gore-Tex® or a Marlex™ mesh and methyl methacrylate sandwich was used in 22 patients, and 9 children did not require reconstruction. Twenty-four (54.5%) patients had normal activity, 3 (6.8%) had occasional discomfort, 2 (4.5%) had pain impairing function, 7 (15.9%) required medication or physical therapy for impairment, and 8 (18.2%) needed additional surgery. Five children (11.4%) developed scoliosis, and all of these patients had posterior rib tumors. Median overall survival for the entire cohort was 41.9±11.82months. Histology (p=0.003), location of tumor on the ribs (p=0.007), and surgical margins (p=0.011) were significantly associated with overall survival. Tumors on the middle and posterior (p=0.003) portions of the ribs had a lower chance of death.

CONCLUSION

Scoliosis is more common in posterior rib resections. Histology, location of the tumor, and surgical margins impact survival, but, type of reconstruction does not.

LEVEL OF EVIDENCE

III.

TYPE OF STUDY

Treatment Study.

Management of pediatric head and neck rhabdomyosarcoma: A case-series of 36 patients

Rhabdomyosarcoma (RMS) is the most common soft tissue sarcoma in the pediatric population. In 35% of cases, RMS develops in the head and neck (H&N) region, and only combined therapy is recognized as a curative treatment. However, recent advances in skull base and reconstructive surgery, along with microsurgery and endoscopic surgery, have strengthened the role of surgery as an important part of RMS treatment. In the present study, 36 pediatric RMS cases (24 males and 12 females) were analyzed after surgical treatment. The average age at diagnosis was 7 years. In total, 67% of tumors were localized in the parameningeal region. Alveolar RMS was the most common histopathological type. A total of 16 patients were treated due to disease recurrence or a previous non-radical surgical procedure, while 19 cases had inductive chemotherapy and/or radiotherapy preceding surgical treatment due to locally advanced disease. In 1 case, only diagnostic biopsy was performed. It is recommended that the management of H&N RMS is interdisciplinary from the beginning. Extensive surgical dissection in the H&N region for RMS may result in severe cosmetic defects and functional impairment; thus, these risks should be considered during treatment planning, and the surgical approach should be based on the individual characteristics of each patient.

Current standards of care in bladder and prostate rhabdomyosarcoma

Rhabdomyosarcoma (RMS) is the most common soft tissue tumor in children, and 15% to 20% arise from the genitourinary tract. Multicenter collaborative studies have improved survival substantially, and in addition to excellent oncologic control, current treatment focuses on organ preservation and minimization of late treatment effects. The multiple modalities needed to treat RMS dictate that treating physicians must be familiar with the disease as well as the goals and possible sequelae of treatment with chemotherapy, radiotherapy, and surgery. This article discusses the current standards of care for bladder and prostate RMS.

Uncovering metabolism in rhabdomyosarcoma

Rhabdomyosarcoma (RMS) is a myogenic tumor classified as the most frequent soft tissue sarcoma affecting children and adolescents. The histopathological classification includes 5 different histotypes, with 2 most predominant referred as to embryonal and alveolar, the latter being characterized by adverse outcome. The current molecular classification identifies 2 major subsets, those harboring the fused Pax3-Foxo1 transcription factor generating from a recurrent specific translocation (fusion-positive RMS), and those lacking this signature but harboring mutations in the RAS/PI3K/AKT signaling axis (fusion-negative RMS). Since little attention has been devoted to RMS metabolism until now, in this review we summarize the "state of art" of metabolism and discuss how some of the molecular signatures found in this cancer, as observed in other more common tumors, can predict important metabolic challenges underlying continuous cell growth, oxidative stress resistance and metastasis, which could be the subject of future targeted therapies.