Clinical and Prognostic Characteristics of 53 Cases of Extracranial Malignant Rhabdoid Tumor in Children. A Single-Institute Experience from 2007 to 2017

Tumoral EIF4EBP1 regulates the crosstalk between tumor-associated macrophages and tumor cells in MRTK

Malignant renal rhabdoid tumor (MRTK) is an aggressive and rare malignancy primarily affecting infants and young children. The intricate interactions within the Tumor Microenvironment (TME) are crucial in shaping MRTK's progression. This study elucidates the significance of tumor-associated macrophages(TAMs) within this milieu and their interplay with eukaryotic translation initiation factor 4E-binding protein 1 (EIF4EBP1) in tumor cells, collectively contributing to MRTK's malignant advancement. Through comprehensive analysis of clinical samples and the TARGET database, EIF4EBP1 emerges as a central macrophage-associated gene with robust prognostic implications. Elevated EIF4EBP1 expression correlates with poor prognosis and heightened infiltration of TAMs. Functional validation demonstrates that EIF4EBP1 knockdown in G401 cells significantly attenuates self-proliferation, migration, and invasion. Moreover, EIF4EBP1 regulates macrophage recruitment and M2 polarization through the ERK/P38 MAPK-MIF axis. Notably, M2 macrophages reciprocally foster the malignant behavior of MRTK tumor cells. This study unveils the pivotal role of EIF4EBP1 in propelling MRTK's malignant progression, unraveling a complex regulatory network involving EIF4EBP1 and TAMs. These findings underscore EIF4EBP1 as a promising biomarker and highlight its therapeutic potential in MRTK management.

Malignant Rhabdoid Tumor and Related Pediatric Tumors: Multimodality Imaging Review with Pathologic Correlation

Malignant rhabdoid tumors (MRTs) are rare but lethal solid neoplasms that overwhelmingly affect infants and young children. While the central nervous system is the most common site of occurrence, tumors can develop at other sites, including the kidneys and soft tissues throughout the body. The anatomic site of involvement dictates tumor nomenclature and nosology. While the clinical and imaging manifestations of MRTs and other more common entities may overlap, there are some site-specific distinctive imaging characteristics. Irrespective of the site of occurrence, somatic and germline mutations in SMARCB1, and rarely in SMARCA4, underlie the entire spectrum of rhabdoid tumors. MRTs have a simple and remarkably stable genome but can demonstrate considerable molecular and biologic heterogeneity. Related neoplasms encompass an expanding category of phenotypically dissimilar (nonrhabdoid tumors driven by SMARC-related alterations) entities. US, CT, MRI, and fluorodeoxyglucose PET/CT or PET/MRI facilitate diagnosis, initial staging, and follow-up, thus informing therapeutic decision making. Multifocal synchronous or metachronous rhabdoid tumors occur predominantly in the context of underlying rhabdoid tumor predisposition syndromes (RTPSs). These autosomal dominant disorders are driven in most cases by pathogenic variants in SMARCB1 (RTPS type 1) and rarely by pathogenic variants in SMARCA4 (RTPS type 2). Genetic testing and counseling are imperative in RTPS. Guidelines for imaging surveillance in cases of RTPS are based on age at diagnosis. ©RSNA, 2024 Supplemental material is available for this article.

Mediastinal malignant rhabdoid tumor in an infant: A rare case report

Mediastinal malignant rhabdoid tumor (MRT) is an exceedingly rare and aggressive neoplasm, particularly uncommon in infants. We present the case of a previously healthy 7-month-old male infant with mediastinal MRT. The patient initially presented with left eyelid ptosis and was otherwise asymptomatic. Initial investigations, including brain MRI, yielded unremarkable results, and the infant was discharged with vitamin B supplements. However, he was readmitted a week later with prolonged fever, poor feeding, diarrhea, and respiratory distress. Despite an initial diagnosis of bronchiolitis/viral respiratory tract infection, the patient's condition rapidly deteriorated. Subsequent evaluation revealed mediastinal MRT as the underlying cause. This case underscores the diagnostic challenges associated with mediastinal MRT in infants and highlights the importance of considering rare neoplastic etiologies in atypical clinical presentations.

Extracranial malignant rhabdoid tumors in children: high mortality even with the help of an aggressive clinical approach

This paper aims to explore the epidemiology, clinical characteristics, and prognosis of extracranial malignant rhabdoid tumors (eMRTs) in children. A systematic review and meta-analysis of studies published in PUBMED, MEDLINE, Web of Science, Embase, Cochrane, and China National Knowledge Infrastructure (CNKI) was conducted. The search was limited to studies published between Jan 1, 1990 to Dec 31, 2022, with the last search done on Jan 31, 2023. We identified 496 papers through the literature search, and 12 retrospective cohort studies with 398 patients were included. The pooled age at diagnosis for malignant rhabdoid tumor of the kidney (MRTK) was 10.009 months (95%CI (7.542-12.476)), while extracranial malignant rhabdoid tumor (EERT) was 25.917 months (95%CI (17.304-34.530)). Among the 398 patients with eMRTs, chemotherapy treatment rate (86.8% (95%CI (74.4-96.0%))) was more frequently than radiotherapy treatment (45.4% (95%CI (38.1-52.6%))). The rate of metastasis in all patients was 41.4% (95%CI (33.9-48.9%)), in which the lung metastasis was occupied 70.4% (95%CI (58.0-81.6%)). SMARCB1/INI1 mutation was up to 93.2% (95%CI (81.3-99.8%)). The rate of total surgical resection was 50.4% (95%CI (35.2-65.6%)), while pooled proportion of death in all patients was 68.7% (95%CI (56.9-79.5%)).     Conclusion: EMRTs are highly malignant tumors associated with high mortality rates. The loss of SMARCB1/INI1 gene and the protein expression is observed in the vast majority of eMRTs patients. Patients that suffered MRTK are younger than patients with extrarenal EERT and are more prone to lung metastasis, but there is no significant difference in overall survival, possibly due to the higher rate of R0 resection of primary tumors in MRTK.     Trial registration: The study was registered on PROSPERO with registration number CRD42023400985. What is Known: • Malignant rhabdoid tumor (MRT) is a rare and highly malignant tumor that may originate from embryonic stem cells. The incidence of MRT is exceptionally low, estimated at 0.00006%. • Malignant rhabdoid tumor of the kidney (MRTK) and extrarenal extra-cranial malignant rhabdoid tumor (EERT) tend to manifest between 11 to 18 months of age, with a 5-year survival rate of approximately 17%-36%. What is New: • There is no comprehensive meta-analysis or large-scale case series that reported to systematically introduce the eMRTs clinic outcome and prog-nosis based on largely pooled data. • This study performed a meta-analysis through an extensive literature search and clinical data analysis in order to mainly explore the clinical characteris-tics and prognosis of eMRTs, improving the understanding of eMRTs in children..

Extra-renal rhabdoid tumor in an adult presenting as cervical adenopathy with spondylodiscitis

INTRODUCTION AND IMPORTANCE

Rhabdoid tumor (RT) is among the most aggressive and lethal types of cancer. It most commonly arises in the central nervous system, kidney, or soft tissues. It typically affects young children.

CASE PRESENTATION

We present a case of a 21 years old man with an extrarenal rhabdoid tumor (ERRT) in the neck extending to the vertebra and epidural space. Clinical presentation was at first misleading as it presented as infectious spondylodiscitis with cervical adenopathies. The patient developed quadriplegia a few days after biopsy was taken and succumbed to his disease a week later.

CLINICAL DISCUSSION

The diagnosis of MRT is mainly based on histopathology, immunohistochemistry and molecular studies. Loss of INI1 expression due to biallelic mutation of the SMARCB1 gene is characteristic. Because of the lack of standardized treatment protocols for MRT, various combinations of chemotherapeutic drugs are used. However, prognosis remains poor especially for cervical vertebral localization as it results in a rapid fatal outcome secondary to respiratory failure.

CONCLUSION

SMARCB1-related biology and potential therapeutic targets are the main focus of preclinical investigations that aim to expand treatment options and improve patient's survival.

CT and MR imaging features of soft tissue rhabdoid tumor: compared with rhabdomyosarcoma in children

Objective

To assess the computed tomography (CT) and magnetic resonance (MR) imaging characteristics of soft tissue rhabdoid tumors (RT) and compare them with those of rhabdomyosarcoma (RMS).

Methods

We conducted a retrospective analysis of 49 pediatric patients from 2011 to 2022, comprising 16 patients with soft tissue RT and 33 patients with RMS who underwent CT or MRI scans. Key imaging features, as well as clinical and pathological data, were compared between the two groups. The multivariate logistic regression analysis was used to determine independent differential factors for distinguishing soft tissue RT from RMS, and the model was established. The final prediction model was visualized by nomograms and verified internally by using a bootstrapped resample 1,000 times. The diagnostic accuracy of the combined model was assessed in terms of discrimination, calibration, and clinical utility.

Results

Age, sex, number of lesions, and primary locations were similar in both groups. The imaging characteristics, including margin, calcification, surrounding blood vessels, and rim enhancement, were associated with the two groups of soft tissue tumors, as determined by univariate analysis (all p < 0.05). On multivariate logistic regression analysis, the presence of unclear margin (p-value, adjusted odds ratio [95% confidence interval]: 0.03, 7.96 [1.23, 51.67]) and calcification (0.012, 30.37 [2.09, 440.70]) were independent differential factors for predicting soft tissue RT over RMS. The presence of rim enhancement (0.007, 0.05 [0.01, 0.43]) was an independent differential factor for predicting RMS over soft tissue RT. The comprehensive model established by logistic regression analysis showed an AUC of 0.872 with 81.8% specificity and 81.3% sensitivity. The decision curve analysis (DCA) curve displayed that the model achieved a better net clinical benefit.

Conclusion

Our study revealed that the image features of calcification, indistinct margins, and a lack of rim enhancement on CT and MRI might be reliable to distinguish soft tissue RT from RMS.

Extrarenal malignant rhabdoid tumor infiltrating the brachial plexus and spinal canal

Extrarenal malignant rhabdoid tumors are rare, aggressive lesions that primarily affect infants and children with characteristic SMARCB1/INI1 mutations. While rhabdoid tumors are most commonly found in the kidneys and central nervous system, they have been reported in virtually every soft tissue in the body. A 20-year-old previously healthy male presented with a 4-month history of left upper extremity weakness and pain and a 1-week history of lower extremity weakness. MRI showed a combined intradural and extradural mass arising from the C8 root and involving the lower trunk of the brachial plexus. CT guided biopsy followed with onsite cytologic analysis initially concerning for plasma cell etiology. Full body PET/CT showed no evidence of metastases. The tumor was surgically resected and debulked. Extensive immunohistochemical testing on the resected specimen revealed a diagnosis of extrarenal malignant rhabdoid tumor. Recurrence invading paraspinous muscles, left lateral paravertebral space, left apical lung, and brachial plexus was noted within 2 months. Radiation and chemotherapy were initiated. Here we present imaging findings, image-guided biopsy, surgical management, and pathologic diagnosis of a rare case of extrarenal, extracranial malignant rhabdoid tumor of the brachial plexus and surrounding paraspinous muscles in a young adult male.

Multidisciplinary management of pediatric malignant rhabdoid tumor based on 5 years of experience at a tertiary care center

OBJECTIVE

Malignant rhabdoid tumor (MRT) is a highly aggressive tumor that occurs mostly in young children with extremely poor prognosis. Standardized and effective treatment strategies for MRT have yet to be established because of its rarity. Here, we report our single-institutional experience involving MRT treatment.

METHODS

Patients with newly diagnosed MRT between March 2016 and October 2021 were included. The clinical characteristic, treatment-related toxicities, clinical outcomes, and prognostic factor were retrospectively analyzed.

RESULTS

A total of 18 patients with MRT were enrolled during the 5 years. The median age was 42.8 months (range 10 to 82 years). Among the 18 patients, 9 patients died after a median of follow-up 26 months (range 3 to 42 months). The 1-year event-free survival (EFS) and 3-year overall survival (OS) rates of the entire cohort were 63% (95% CI 46% to 74%) and 67% (95% CI 49% to 82%), respectively. Univariate analysis of patients who underwent gross or total resection followed by adjuvant chemotherapy and radiotherapy demonstrated an improvement in 1-year EFS. However, only gross resection and total resection predicted a better 3-year OS.

CONCLUSIONS

Surgical excision is still the mainstream treatment for MRT. Postoperative adjuvant treatments including chemotherapy and radiotherapy contribute to improved disease control rate. Our single-institute experience may provide insights into the multimodal treatment of MRT.

Dual targeting of EZH1 and EZH2 for the treatment of malignant rhabdoid tumors

Malignant rhabdoid tumors (MRTs) are rare and highly aggressive pediatric cancers with no standard of care. MRTs are characterized by loss of SMARCB1, which results in upregulated expression of enhancer of zeste homolog 2 (EZH2), which is responsible for the methylation of lysine 27 of histone H3 (H3K27me3), leading to the repression of gene expression. Although previous reports suggest EZH2 as an effective therapeutic target, the functions of EZH1, the other homolog of EZH, in MRT remain unknown. Here, we show that EZH1, as well as EZH2, contributes to MRT cell growth and H3K27 methylation. Depletion or selective inhibition of EZH2 led to a compensatory increase in EZH1 expression, and depletion of EZH1 enhanced the effect of EZH2 inhibition. EZH1/2 dual inhibitors suppressed MRT cell growth markedly, reflecting the reduction of H3K27me3 accumulation at one of the EZH1/2 targets, the CDKN2A locus. Dual inhibition of EZH1/2 in vivo suppressed tumor growth completely, with no significant adverse effects. These findings indicate that both EZH1 and EZH2 are potential targets for MRT therapy, and that EZH1/2 dual inhibitors may be promising therapeutic strategies for MRT.

Congenital Malignant Rhabdoid Tumor of Neck

Malignant rhabdoid tumors (MRT) are uncommon, highly aggressive tumors arising usually from the central nervous system and kidneys. Nonrenal and noncentral nervous systems MRT are rare in neonates. To the best of our knowledge, only five cases of congenital MRT of neck have been described till date. We present a rare case of congenital MRT of the neck in a neonate along with review of literature.

Fetal-onset malignant rhabdoid tumor: a case report

Background

A fetal-onset cervical mass may cause postnatal airway obstruction, and ex utero intrapartum treatment (EXIT) to secure the airway while maintaining fetal-placental circulation may be life-saving. Malignant rhabdoid tumors (MRT) are highly aggressive tumors, and when they develop in utero, the prognosis is even worse, with almost no reports of survival beyond the neonatal period. Herein, we report a case of a primary cervical MRT and describe our treatment using EXIT for securing the airway, wherein the infant’s life was saved.

Case presentation

A 40-year-old Japanese woman with no relevant medical or surgical history was diagnosed with a fetal left cervical mass and polyhydramnios during the third trimester. Fetal magnetic resonance imaging indicated the possibility of postnatal airway obstruction, and delivery using EXIT was planned. The infant was delivered by a planned cesarean section at 39 weeks and 5 days gestation, and tracheostomy was performed using EXIT. Postnatal contrast-enhanced computed tomography revealed suspected metastatic lesions in the subcutaneous tissue, lungs, and thymus, in addition to the mass in the left cervical region. MRT was diagnosed by biopsy of a subcutaneous mass in the left thigh, and chemotherapy with vincristine, doxorubicin, cyclophosphamide, ifosfamide, and etoposide was initiated. The tumors regressed, and the infant was successfully weaned from artificial ventilation. After discharge from the hospital, she had a recurrent cervical mass and intracranial metastasis, and radiotherapy was initiated.

Conclusions

In our case, fetal diagnosis enabled advance planning of delivery using EXIT, thus saving the infant’s life. The use of chemotherapy for MRT, which has a poor prognosis, allowed tumor regression and enabled the infant to survive beyond the neonatal period.

Immune-Related LncRNAs as Prognostic Factors for Pediatric Rhabdoid Tumor of the Kidney

Background

Immune-related long noncoding RNAs (IrlncRNAs) are recognized as important prognostic factors in a variety of cancers, but thus far, their prognostic value in pediatric rhabdoid tumor of the kidney (pRTK) has not been reported. Here, we clarified the associations between IrlncRNAs and overall survival (OS) of pRTK patients and constructed a model to predict their prognosis.

Methods

We accessed RNA sequencing data and corresponding clinical data of pRTK from the Therapeutically Applicable Research to Generate Effective Treatments (TARGET) database. An expression profile of immune-related genes (Irgenes) and lncRNAs of pRTK was extracted from the RNA sequencing data. IrlncRNAs were defined by co-expression analysis of lncRNAs and Irgenes. The limma R package was used to identify differential expression IrlncRNAs. Univariate and multivariate Cox regression analyses were conducted to build a prognostic IrlncRNAs model. The performance of this prognostic model was validated by multimethods, like ROC curve analysis.

Results

A total of 1097 IrlncRNAs were defined. Univariate Cox regression analysis identified 7 IrlncRNAs (AC004791.2, AP003068.23, RP11-54O7.14, RP11-680F8.1, TBC1D3P1-DHX40P1, TUNAR, and XXbac-BPG308K3.5) and were significantly associated with OS. Multivariate regression analysis constructed the best prognostic model based on the expression of AC004791.2, AP003068.23, RP11-54O7.14, TBC1D3P1-DHX40P1, and TUNAR. According to the prognostic model, a risk score of each patient was calculated, and patients were divided into high-risk and low-risk groups accordingly. The survival time of low-risk patients was significantly better than high-risk patients (p < 0.001). Univariate (hazard ratio 1.098, 95% confidence interval 1.048-1.149, p value <0.001) and multivariate (hazard ratio 1.095, 95% confidence interval 1.043-1.150, p value <0.001) analyses confirmed that the prognostic model was reliable and independent in prediction of OS. Time-dependent ROC analysis showed that 1-year survival AUC of prognostic model, stage, age, and sex was 0.824, 0.673, 0.531, and 0.495, respectively, which suggested that the prognostic model was the best predictor of survival in pRTK patients.

Conclusions

The prognostic model based on 5 IrlncRNAs was robust and could better predict the survival of pRTK than other clinical factors. Additionally, the mechanism of regulation and action of prognosis-associated lncRNAs could provide new avenues for basic research to explore the mechanism of tumor initiation and development in order to prevent and treat pRTK.

Diverse outcomes in extra-cranial rhabdoid tumors: A single institute experience

Rhabdoid tumors (RTs) are a rare and aggressive pediatric cancer that commonly presents with alterations in the tumor suppressor gene SMARCB1. However, RT prognosis is still poor, with no standard treatment available. Moreover, no predictive biomarkers have been identified for determining its aggressiveness or chemo- and radio-sensitivities. Herein, four cases of extra-cranial RTs (ERTs) are described, two of whom are long-term survivors. These two surviving patients were positive for p16, whereas the other two were p16-negative. Our findings suggest that biologically distinct types of ERTs exist and that p16 expression may be a potential positive prognostic biomarker of ERTs. Nevertheless, further studies are required to confirm our findings.

Current and Emerging Therapeutic Approaches for Extracranial Malignant Rhabdoid Tumors

Extracranial malignant rhabdoid tumors (extracranial MRT) are rare, highly aggressive malignancies affecting mainly infants and children younger than 3 years. Common anatomic sites comprise the kidneys (RTK – rhabdoid tumor of kidney) and other soft tissues (eMRT – extracranial, extrarenal malignant rhabdoid tumor). The genetic origin of these diseases is linked to biallelic pathogenic variants in the genes SMARCB1, or rarely SMARCA4, encoding subunits of the SWI/SNF chromatin-remodeling complex. Even if extracranial MRT seem to be quite homogeneous, recent epigenome analyses reveal a certain degree of epigenetic heterogeneity. Use of intensified therapies has modestly improved survival for extracranial MRT. Patients at standard risk profit from conventional therapies; most high-risk patients still experience a dismal course and often therapy resistance. Discoveries of clinical and molecular hallmarks and the exploration of experimental therapeutic approaches open exciting perspectives for clinical and molecularly stratified experimental treatment approaches. To ultimately improve the outcome of patients with extracranial MRTs, they need to be characterized and stratified clinically and molecularly. High-risk patients need novel therapeutic approaches including selective experimental agents in phase I/II clinical trials.

A Systematic Review and Meta-Analysis of Malignant Rhabdoid and Small Cell Undifferentiated Liver Tumors: A Rational for a Uniform Classification

Simple Summary

Malignant rhabdoid tumors of the liver are very rare pediatric liver tumors with a devastating prognosis. It is currently unclear which histological subtypes of pediatric liver tumors belong to this entity and how these tumors should be treated. In this systematic review with meta-analysis, we analyzed all reports on pediatric patients with malignant rhabdoid liver tumors, but also with so-called small cell undifferentiated liver tumors. This is another rare liver tumor subtype that has recently been regarded to belong to the entity of rhabdoid tumors by some authors. The main result of this study is that these two tumor subtypes show large overlap on several levels and even mixtures of both histological patterns have been documented. Our meta-analysis provides an evidence base for the recommendation to classify these two tumor subtypes as one entity. We showed that treatment of these tumors with hepatoblastoma directed chemotherapy is ineffective and that a therapy with chemotherapy regimens initially applied for soft tissue sarcoma is associated with a significantly better survival. This study represents the highest level of evidence available for these rare liver tumors.

Abstract

Background: Rhabdoid liver tumors in children are rare and have a devastating prognosis. Reliable diagnosis and targeted treatment approaches are urgently needed. Immunohistochemical and genetic studies suggest that tumors formerly classified as small cell undifferentiated hepatoblastoma (SCUD) belong to the entity of malignant rhabdoid tumors of the liver (MRTL), in contrast to hepatoblastomas with focal small cell histology (F-SCHB). This may have relevant implications on therapeutic approaches. However, studies with larger cohorts investigating the clinical relevance of the histological and genetic similarities for patients are lacking. Purpose: To analyze possible similarities and differences in patient characteristics, tumor biology, response to treatment, and clinical course of patients with MRTL, SCUD and F-SCHB. Applied therapeutic regimens and prognostic factors are investigated. Methods: A systematic literature search of MEDLINE, Web of Science, and CENTRAL was performed for this PRISMA-compliant systematic review. All studies of patients with MRTL, SCUD and F-SCHB that provided individual patient data were included. Demographic, histological, and clinical characteristics of the three subgroups were compared. Overall survival (OS) was estimated with the Kaplan–Meier method and prognostic factors investigated in a multivariable Cox regression model. Protocol registered: PROSPERO 2021 CRD42021258760. Results: Fifty-six studies with a total of 118 patients were included. The two subgroups MRTL and SCUD did not differ significantly in baseline patient characteristics. However, heterogenous diagnostic and therapeutic algorithms were applied. Large histological and clinical overlap between SCUD and MRTL could be shown. Two-year OS was 22% for MRTL and 13% for SCUD, while it was significantly better in F-SCHD (86%). Chemotherapeutic regimens for hepatoblastoma proved to be ineffective for both SCUD and MRTL, but successful in F-SCHB. Soft tissue sarcoma chemotherapy was associated with significantly better survival for MRTL and SCUD, but was rarely applied in SCUD. Patients who did not undergo surgical tumor resection had a significantly higher risk of death. Conclusions: While F-SCHB is a subtype of HB, SCUD should be classified and treated as a type of MRTL. Surgical tumor resection in combination with intensive, multi-agent chemotherapy is the only chance for cure of these tumors. Targeted therapies are highly needed to improve prognosis. Currently, aggressive regimens including soft tissue sarcoma chemotherapy, extensive resection, radiotherapy or even liver transplantation are the only option for affected children.

Non-rhabdomyosarcoma soft tissue sarcomas diagnosed in patients at a young age. An overview of clinical, pathological, and molecular findings

OBJECTIVE

Disease spectrum in pediatric sarcoma differs substantially from adults. We report a cohort of very young children with non-rhabdomyosarcoma soft tissue sarcoma (NRSTS) detailing their molecular features, treatment, and outcome.

METHODS

We report features of consecutive children (age <2 years) with NRSTS (2000-2017). Archival pathological material was re-reviewed, with additional molecular techniques applied where indicated.

RESULTS

Twenty-nine patients (16 females, 55%) were identified (median age 6 months; range 0-23). Most common diagnoses included infantile fibrosarcoma (IFS, n = 14, 48%), malignant rhabdoid tumor (MRT, n = 4, 14%), and undifferentiated sarcoma (n = 4, 14%). Twenty-seven of 29 (93%) had tumor molecular characterization to confirm diagnosis. Clinical presentation included a swelling/mass (n = 23, 79%). Disease extent was localized (n = 20, 69%), locoregional (n = 6, 21%), or metastatic (n = 3, 10%). Seventeen of 29 (59%) who underwent surgery achieved complete resection (R0). Other treatments included conventional chemotherapy (n = 26, 90%), molecularly targeted therapies (n = 3, 10%), and radiation (n = 5, 17%). At last follow-up (median 3 years; range 0.3-16.4), 23 (79%) were alive, disease-free and six (21%) had died of disease. All patients with IFS were alive and all those with MRT died. A cancer predisposition syndrome (CPS) was confirmed in three of 10 (30%) genetically tested patients.

CONCLUSION

We recommend tumor molecular characterization in all young patients including evaluation for CPS to optimize treatment options and prognostication.

An analysis of the diagnosis, clinical characteristics, treatment, and survival outcomes of 36 extracranial malignant rhabdoid tumor patients

BACKGROUND

Extracranial malignant Rhabdoid tumors (eMRTs) are rare but aggressive lesions in young children. This work aimed to review and analyze the diagnosis, clinical characteristics, treatment, and survival of eMRTs so as to summarize experience for future therapy.

METHODS

A total of 36 eMRT cases were treated between January 2008 and August 2019 according to Shanghai Children's Medical Center (SCMC) multimodal protocol of mixed surgery, radiation and chemotherapy involving vincristine, carboplatin, doxorubicin, etoposide, cyclophosphamide and ifosfamide. We collected information including: age at diagnosis, tumor location, disease stage, therapy, outcomes, etc. Overall survival (OS) and event free survival (EFS) were calculated and risk factors for survival were analyzed.

RESULTS

The patients had a median age of 1.80 years at diagnosis (range, 1.4 m-13.42 years), and were followed up for 9.17 months in median (range, 4 d-11.14 y). A total of 16 patients achieved complete remission (CR), and 7 survived without reoccurrence till December 2019. The 3-year EFS was 17.4% (95% CI: 11.0-23.8%) with a 3-year OS of 23.4% (95% CI: 15.8-31.0%). Recurrence was found only in children younger than the median age (1.80 y). Localized staging (Log Rank P=0.039 for OS and P=0.021) and older age (Log Rank P=0.016 for OS and P=0.002 for EFS) were associated with improved outcome. Younger age (Cox regression, OS, OR =2.610, 95% CI: 1.147-5.937, P=0.022; EFS, OR =3.401, 95% CI: 1.495-7.752, P=0.004) were independent risk factors for death and recurrence.

CONCLUSIONS

Those eMRTs treated according to SCMC protocol turned out to have poor outcomes. Higher staging at diagnosis and reoccurrence in younger patients remain major threats to the prognosis.

Infantile Extracranial Rhabdoid Tumor of the Scalp

Extracranial rhabdoid tumor is a rare tumor that can originate in multiple organs, and it is most commonly seen in the kidneys. This tumor has a grave prognosis. We report to the best of our knowledge the first case of infantile scalp extracranial rhabdoid tumor in a 6-month-old male baby who presented with a right parietal scalp mass since the age of 1 month. This mass was initially diagnosed as scalp hemangioma based on clinical and imaging findings. However, this mass was growing fast which necessitated excision. Pathologic examination after excision showed a malignant tumor composed of sheets of rhabdoid cells. Immunohistochemically, this tumor tested positive for vimentin, CD 99, glypican-3, synaptopysin, WT-1, CK, and EMA. INI-1 immunostain was lost in the tumor cells. Subsequently, this tumor was pathologically diagnosed as extracranial scalp rhabdoid tumor. After tumor excision, the patient was referred to pediatric oncology to receive chemotherapy. Experience with scalp extracranial rhabdoid tumors is limited. However, this tumor in other organs carries a grave prognosis. Although scalp extracranial rhabdoid tumor is an extremely rare tumor, it should be kept in mind in the differential diagnosis of infantile scalp masses given the need of combined surgical and chemotherapeutic treatment.

Identification of prognostic immune-related genes in rhabdoid tumor of kidney based on TARGET database analysis

Background: Malignant rhabdoid tumor of the kidney (RTK) is a rare and highly aggressive pediatric malignancy. Immune system dysfunction is significantly correlated with tumor initiation and progression.

Methods: We integrated and analyzed the expression profiles of immune-related genes (IRGs) in 65 RTK patients based on the Therapeutically Applicable Research to Generate Effective Treatments (TARGET) database. Prognostic related IRGs in RTK patients were analyzed using univariate and multivariate analysis, based on which a prognostic model with IRGs was constructed. Correlation analysis between the risk score of our model and tumor-infiltrating cell were also investigated.

Results: Twenty two IRGs were significantly associated with the clinical outcomes of RTK patients. Gene ontology (GO) analysis revealed that inflammatory pathways were most frequently implicated in RTK. A prognostic model was constructed using 7 IRGs (MMP9, SERPINA3, FAM19A5, CCR9, PLAUR, IL1R2, PRKCG), which were independent prognostic indices that could differentiate patients based on their survival outcomes. Furthermore, the risk scores from our prognostic model was positively associated with cancer-associated fibroblasts (CAFs).

Conclusions: We screened seven IRGs of clinical significance to distinguish patients with different survival outcomes. This may enhance our understanding of the immune microenvironment of RTK, and could use to design individualized treatments for RTK patients.

Background: Malignant rhabdoid tumor of the kidney (RTK) is a rare and highly aggressive pediatric malignancy. Immune system dysfunction is significantly correlated with tumor initiation and progression.

Methods: We integrated and analyzed the expression profiles of immune-related genes (IRGs) in 65 RTK patients based on the Therapeutically Applicable Research to Generate Effective Treatments (TARGET) database. Prognostic related IRGs in RTK patients were analyzed using univariate and multivariate analysis, based on which a prognostic model with IRGs was constructed. Correlation analysis between the risk score of our model and tumor-infiltrating cell were also investigated.

Results: Twenty two IRGs were significantly associated with the clinical outcomes of RTK patients. Gene ontology (GO) analysis revealed that inflammatory pathways were most frequently implicated in RTK. A prognostic model was constructed using 7 IRGs (MMP9, SERPINA3, FAM19A5, CCR9, PLAUR, IL1R2, PRKCG), which were independent prognostic indices that could differentiate patients based on their survival outcomes. Furthermore, the risk scores from our prognostic model was positively associated with cancer-associated fibroblasts (CAFs).

Conclusions: We screened seven IRGs of clinical significance to distinguish patients with different survival outcomes. This may enhance our understanding of the immune microenvironment of RTK and could use to design individualized treatments for RTK patients.

Malignant rhabdoid tumours of the small intestine with multiple organ involvement: Case report

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Malignant rhabdoid tumours (MRTs) are aggressive disease with poor prognosis.

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Small intestine is the rare site of MRTs and curative resection is important.

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Effective systemic therapies are needed for MRTs with multiple organ involvement.

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Clinical trials are ongoing to develop new therapies for MRTs.

Introduction and importance

Malignant rhabdoid tumours (MRTs) were first described as an infrequent variant of Wilms’ tumour and have been reported in several organs. The small intestine is a rare site for MRTs.

Case presentation

A 70-year-old man presented with appetite loss and melena. Haemorrhagic small intestinal tumours, swollen mesenteric and paraaortic lymph nodes, a tumour in the left kidney, and multiple tumours in the lung were found. He underwent partial resection of two haemorrhagic small intestinal tumours classified as MRTs based on the results of a pathological examination. However, melena appeared again on postoperative day 6. We performed another operation and resected approximately 180 cm of the small intestine that contained multiple tumours. All lesions were classified as MRTs. Unfortunately, melena appeared again 4 days after the second operation. He did not want invasive therapy and died from massive melena 2 months after the initial surgery.

Clinical discussion

MRTs of the small intestine are uncommon and have an extremely poor prognosis. Although curative resection is an important treatment, cases of metastasis at diagnosis and postoperative early recurrence have been observed, as was the case for the patient described herein. In these cases, effective systemic therapy is necessary. Recently, tumour suppressor genes were shown to be involved in the occurrence of MRT, and new therapies for MRT have been studied.

Conclusion

We herein conclude effective systemic therapy is necessary for MRTs with multiple organ involvement. The development of new drugs for this disease is ongoing.

Clinical and genetic risk factors define two risk groups of extracranial malignant rhabdoid tumours (eMRT/RTK)

INTRODUCTION

Extracranial rhabdoid tumours are rare, highly aggressive malignancies primarily affecting young children. The EU-RHAB registry was initiated in 2009 to prospectively collect data of rhabdoid tumour patients treated according to the EU-RHAB therapeutic framework.

METHODS

We evaluated 100 patients recruited within EU-RHAB (2009-2018). Tumours and matching blood samples were examined for SMARCB1 mutations by sequencing and cytogenetics.

RESULTS

A total of 70 patients presented with extracranial, extrarenal tumours (eMRT) and 30 with renal rhabdoid tumours (RTK). Nine patients demonstrated synchronous tumours. Distant metastases at diagnosis (M+) were present in 35% (35/100), localised disease (M0) with (LN+) and without (LN-) loco-regional lymph node involvement in 65% (65/100). SMARCB1 germline mutations (GLM) were detected in 21% (17/81 evaluable) of patients. The 5-year overall survival (OS) and event-free survival (EFS) rates were 45.8 ± 5.4% and 35.2 ± 5.1%, respectively. On univariate analyses, age at diagnosis (≥12 months), M0-stage, absence of synchronous tumours, absence of a GLM, gross total resection (GTR), radiotherapy and achieving a CR were significantly associated with favourable outcomes. In an adjusted multivariate model presence of a GLM, M+ and lack of a GTR were the strongest significant negative predictors of outcome.

CONCLUSIONS

We suggest to stratify patients with localised disease (M0), GTR+ and without proof of a GLM (5-year OS 72.2 ± 9.9%) as 'standard risk'. Patients presenting with one of the features M+ and/or GTR- and/or GLM+ belong to a high risk group (5-year, OS 32.5 ± 6.2%). These patients need novel therapeutic strategies such as combinations of targeted agents with conventional chemotherapy or novel experimental approaches ideally within international phase I/II trials.