Multimodality Imaging Evaluation of Nasal Rhabdomyosarcoma in Adults: A Case Report and Literature Review

BACKGROUND

Alveolar rhabdomyosarcoma (ARMS) predominantly affects adolescents aged 10-15 years and is distinguished by its high aggressiveness and adverse prognosis compared with other sarcomas. It exhibits a pronounced tendency for lymphatic and hematogenous metastases at early stages. ARMS commonly manifests in the limbs and genitourinary system, with occurrences in the head and neck region being relatively uncommon. The role of CT, MRI, and 18F-FDG positron emission tomography combined with computed tomography (PET/CT) in the diagnostic process of ARMS is yet to be fully established.

CASE REPORT

We report the case of a 49-year-old woman who presented with hematological nasal discharge for one month. CT imaging revealed a soft tissue mass in the left nasal cavity. MRI demonstrated a marginally hypo- to isointense signal on T1-weighted images, a hyperintense signal on T2-weighted images, and heterogeneous enhancement post-contrast. 18F-FDG PET/CT identified a hypermetabolic lesion located within the left nasal cavity. Surgical intervention entailed the excision of the left intranasal mass and the skull base lesion. Postoperative pathological analysis indicated ARMS.

CONCLUSION

Sinus ARMS is notably malignant and associated with a dismal prognosis. Accurate diagnosis depends on histopathological and immunohistochemical evaluation, complemented by genetic analysis for specific chromosomal translocations and fusion genes. Imaging techniques, including CT, MRI, and PET/CT, are crucial for assessing lesion extent and metastasis, supporting disease diagnosis, informing treatment choices, facilitating surgical planning, and monitoring response to therapy.

FOXO1 and PAX5 Rearrangement in Alveolar Rhabdomyosarcoma in Saudi Pediatric Patients

Objective: In this study, we investigate the molecular rearrangement of FOXO1 in alveolar rhabdomyosarcoma (ARHS) in Saudi pediatric patients. Method: We performed a molecular detection of molecular translocation in 30 pediatric cases of ARHS using FOXO1 dual color break-apart FISH probe (ZytoLight®, 13q14.11) and PAX5 dual color break-apart FISH probe (ZytoLight®, 9p13.2). Results: All analyzable cases of ARHS demonstrated FOXO1 translocation whereas PAX5 translocation was not detected in any case. Conclusion: Although the testing for PAX5 rearrangement was based on protein-protein network analysis, our study showed that PAX5 translocation is not conspicuous in ARHS. PAX7/3::FOXO1 fusion genes feature ARMS, rendering crossreactivity between PAX7 and PAX3 a possible explanation. Nevertheless, PAX5 immunoreactivity and molecular translocation could be an adjunctive pathway that is confined to aggressive ARMS.

Exon skipping in genes encoding lineage-defining myogenic transcription factors in rhabdomyosarcoma

Rhabdomyosarcoma (RMS) is a childhood sarcoma composed of myoblast-like cells, which suggests a defect in terminal skeletal muscle differentiation. To explore potential defects in the differentiation program, we searched for mRNA splicing variants in genes encoding transcription factors driving skeletal muscle lineage commitment and differentiation. We studied two RMS cases and identified altered splicing resulting in "skipping" the second of three exons in MYOD1. RNA-Seq data from 42 tumors and additional RMS cell lines revealed exon 2 skipping in both MYOD1 and MYF5 but not in MYF6 or MYOG. Complementary molecular analysis of MYOD1 mRNA found evidence for exon skipping in 5 additional RMS cases. Functional studies showed that so-called MYODΔEx2 protein failed to robustly induce muscle-specific genes, and its ectopic expression conferred a selective advantage in cultured fibroblasts and an RMS xenograft. In summary, we present previously unrecognized exon skipping within MYOD1 and MYF5 in RMS, and we propose that alternative splicing can represent a mechanism to alter the function of these two transcription factors in RMS.

[Alveolar rhabdomyosarcoma: Two fusion-negative cases lacking PAX3-FOXO1 and PAX7-FOXO1]

Rhabdomyosarcoma is the most common soft tissue sarcoma in childhood and adolescence. Morphologically, two major forms are described: alveolar and embryonal rhabdomyosarcoma. The former is generally associated with a poorer prognosis and it usually harbors a characteristic fusion gene, PAX3/7-FOXO1, that is used to confirm the diagnosis. We present two cases, both of which exhibited the classic alveolar histology with immunohistochemical myogenic differentiation (Desmin, MYOD-1 and Myogenin expression) and lacked the characteristic fusion gene PAX3/7-FOXO1. The aim of this report is to highlight the importance of the molecular status in the study and diagnosis of these cases, as it seems to be not only a useful diagnostic tool, but also an important prognostic factor.

Autoantibody profiling of alveolar rhabdomyosarcoma patients unveils tumor-associated antigens with diagnostic and prognostic significance

Alveolar rhabdomyosarcoma (ARMS) is a highly aggressive subtype of childhood cancer for which efficacious treatments are needed. Immunotherapy represents a new therapeutic opportunity to pursue, but it requires the identification of worthwhile tumor antigens. Herein, we exploited the capacity of ARMS autoantibodies to recognize tumor self-antigens, probing human protein microarrays with plasma from ARMS patients and healthy subjects. We assessed the autoantibody response in ARMS, validated data with independent techniques, and estimated autoantibodies diagnostic and prognostic significance by receiver-operator characteristic curves (ROC), uni- and multivariate analysis. Of the 48 tumor antigens identified, General Transcription Factor II-I (GTF2i) and Protocadherin Gamma Subfamily C5 (PCDHGC5) were selected as candidate targets to validate tumor-restricted antigen expression and autoantibody reactivity through an independent technique and wider cohort of cases. GTF2i and PCDHGC5 overexpression was observed in tumor tissues compared to normal counterparts, and anti-GTF2i and -PCDHGC5 autoantibodies were found able to distinguish ARMS patients from healthy subjects as well as cases with different histology. Moreover, low levels of PCDHGC5 autoantibodies characterized patients with worse event-free survival and proved to be an independent negative prognostic factor. This approach provided the first comprehensive autoantibody profile of ARMS, gave novel insights into the immune response of this malignancy and paved the way toward novel potential antibody-based therapeutic applications suitable to improve the survival of ARMS patients.

Magnetic resonance features and cranial nerve involvement in pediatric head and neck rhabdomyosarcomas

PURPOSE

Rhabdomyosarcoma (RMS) is a malignant tumor frequent in children. The frequency and characteristics of cranial nerve involvement in pediatric head and neck (H&N) RMS have been scarcely reported. The aim of this study is to review a large cohort of pediatric head and neck RMS with an emphasis on cranial nerve involvement.

METHODS

We retrospectively reviewed H&N RMS cases from 3 tertiary hospitals over a 10-year period. Cranial nerve involvement was defined as radiologically apparent tumor extension along a nerve and/or the presence of secondary signs. Scans were reviewed by two pediatric neuroradiologists, blinded to clinical data.

RESULTS

A total of 52 patients met the inclusion criteria. Histologically, 39/52 were embryonal RMS, while 13/52 were alveolar RMS. Regional lymph nodes metastases were present in 19.2%. Cranial nerve involvement was present in 36.5%. Nerves were mainly involved as a direct extension of the mass through skull base foramina or after invasion of cavernous sinus, Meckel's cave, orbital apex, or stylomastoid foramen.

CONCLUSION

Cranial nerve involvement is frequent in pediatric head and neck RMS and occurs secondary to "geographic" invasion due to direct extension through skull base foramina or cavernous sinus. These tumors never showed distant perineural metastatic disease as is seen in cases of adult head and neck carcinomas. This implies a different biological interaction between the nerves and these tumors in comparison to adult H&N tumors.

GEIS-SEHOP clinical practice guidelines for the treatment of rhabdomyosarcoma

Rhabdomyosarcoma (RMS) is the most frequent soft tissue sarcoma (STS) in children and adolescents. In Spain the annual incidence is 4.4 cases per million children < 14 years. It is an uncommon neoplasm in adults, but 40% of RMS are diagnosed in patients over 20 years of age, representing 1% of all STS in this age group. RMS can appear anywhere in the body, with some sites more frequently affected including head and neck, genitourinary system and limbs. Assessment of a patient with suspicion of RMS includes imaging studies (MRI, CT, PET-CT) and biopsy. All patients with RMS should receive chemotherapy, either at diagnosis in advanced or metastatic stages, or after initial resection in early local stages. Local control includes surgery and/or radiotherapy depending on site, stage, histology and response to chemotherapy. This guide provides recommendations for diagnosis, staging and treatment of this neoplasm.

DCX and CRABP2 are candidate genes for differential diagnosis between pre-chemotherapy embryonic and alveolar rhabdomyosarcoma in pediatric patients

IMPORTANCE

Rhabdomyosarcoma (RMS) is the most common soft tissue sarcoma in children. More than 90% of cases are classified as embryonic RMS (ERMS) or alveolar RMS (ARMS). ERMS has a worse prognosis than ARMS. Early differential diagnosis is of paramount importance for optimization of treatment.

OBJECTIVE

To identify genes that are differentially expressed between ARMS and ERMS, which can be used for accurate rhabdomyosarcoma classification.

METHODS

Three Gene Expression Omnibus datasets composed of ARMS and ERMS samples were screened and 35 differentially expressed genes (DEGs) were identified. Receiver operating characteristic curve analysis and area under the curve analysis was performed for these 35 DEGs and seven candidate genes with the best differential expression scores between ARMS and ERMS were determined. The expression of these seven candidate genes was validated by immunohistochemical analysis of pre-chemotherapy ARMS and ERMS specimens.

RESULTS

The levels of DCX and CRABP2 were confirmed to be remarkably different between paraffin-embedded ARMS and ERMS tissues, while EGFR abundance was only marginally different between these two RMS subtypes.

INTERPRETATION

DCX and CRABP2 are potential biomarkers for distinguishing ARMS from ERMS in pre-chemotherapy pediatric patients.

Vincetoxicum arnottianum modulates motility features and metastatic marker expression in pediatric rhabdomyosarcoma by stabilizing the actin cytoskeleton

Background

Prevention of metastatic invasion is one of the main challenges in the treatment of alveolar rhabdomyosarcoma. Still the therapeutic options are limited. Therefore, an anti-tumor screening was initiated focusing on the anti-metastatic and anti-invasion properties of selected medicinal plant extracts and phytoestrogens, already known to be effective in the prevention and treatment of different cancer entities.

Methods

Treatment effects were first evaluated by cell viability, migration, invasion, and colony forming assays on the alveolar rhabdomyosarcoma cell line RH-30 in comparison with healthy primary cells.

Results

Initial anti-tumor screenings of all substances analyzed in this study, identified the plant extract of Vincetoxicum arnottianum (VSM) as the most promising candidate, harboring the highest anti-metastatic potential. Those significant anti-motility properties were proven by a reduced ability for migration (60%), invasion (99%) and colony formation (61%) under 48 h exposure to 25 μg/ml VSM. The restricted motility features were due to an induction of the stabilization of the cytoskeleton – actin fibers were 2.5-fold longer and were spanning the entire cell. Decreased proliferation (PCNA, AMT, GCSH) and altered metastasis (e. g. SGPL1, CXCR4, stathmin) marker expression on transcript and protein level confirmed the significant lowered tumorigenicity under VSM treatment. Finally, significant alterations in the cell metabolism were detected for 25 metabolites, with levels of uracil, N-acetyl serine and propanoyl phosphate harboring the greatest alterations. Compared to the conventional therapy with cisplatin, VSM treated cells demonstrated a similar metabolic shutdown of the primary cell metabolism. Primary control cells were not affected by the VSM treatment.

Conclusions

This study revealed the VSM root extract as a potential, new migrastatic drug candidate for the putative treatment of pediatric alveolar rhabdomyosarcoma with actin filament stabilizing properties and accompanied by a marginal effect on the vitality of primary cells.

Graphical abstract

Supplementary Information

The online version contains supplementary material available at 10.1186/s12906-021-03299-x.

Differential regulation of autophagy by STAU1 in alveolar rhabdomyosarcoma and non-transformed skeletal muscle cells

PURPOSE

Recent work has highlighted the therapeutic potential of targeting autophagy to modulate cell survival in a variety of diseases including cancer. Recently, we found that the RNA-binding protein Staufen1 (STAU1) is highly expressed in alveolar rhabdomyosarcoma (ARMS) and that this abnormal expression promotes tumorigenesis. Here, we asked whether STAU1 is involved in the regulation of autophagy in ARMS cells.

METHODS

We assessed the impact of STAU1 expression modulation in ARMS cell lines (RH30 and RH41), non-transformed skeletal muscle cells (C2C12) and STAU1-transgenic mice using complementary techniques.

RESULTS

We found that STAU1 silencing reduces autophagy in the ARMS cell lines RH30 and RH41, while increasing their apoptosis. Mechanistically, this inhibitory effect was found to be caused by a direct negative impact of STAU1 depletion on the stability of Beclin-1 (BECN1) and ATG16L1 mRNAs, as well as by an indirect inhibition of JNK signaling via increased expression of Dual specificity phosphatase 8 (DUSP8). Pharmacological activation of JNK or expression silencing of DUSP8 was sufficient to restore autophagy in STAU1-depleted cells. By contrast, we found that STAU1 downregulation in non-transformed skeletal muscle cells activates autophagy in a mTOR-dependent manner, without promoting apoptosis. A similar effect was observed in skeletal muscles obtained from STAU1-overexpressing transgenic mice.

CONCLUSIONS

Together, our data indicate an effect of STAU1 on autophagy regulation in ARMS cells and its differential role in non-transformed skeletal muscle cells. Our findings suggest a cancer-specific potential of targeting STAU1 for the treatment of ARMS.

ACTA1 is inhibited by PAX3-FOXO1 through RhoA-MKL1-SRF signaling pathway and impairs cell proliferation, migration and tumor growth in Alveolar Rhabdomyosarcoma

Background

Alveolar Rhabdomyosarcoma (ARMS) is a pediatric malignant soft tissue tumor with skeletal muscle phenotype. Little work about skeletal muscle proteins in ARMS was reported. PAX3-FOXO1 is a specific fusion gene generated from the chromosomal translocation t (2;13) (q35; q14) in most ARMS. ACTA1 is the skeletal muscle alpha actin gene whose transcript was detected in ARMS. However, ACTA1 expression and regulation in ARMS have not been well investigated. This work aims to explore the expression, regulation and potential role of ACTA1 in ARMS.

Results

ACTA1 protein was detected in the studied RH30, RH4 and RH41 ARMS cells. ACTA1 was found to be inhibited by PAX3-FOXO1 at transcription and protein levels by employing western blot, luciferase reporter, qRT-PCR and immunofluorescence assays. The activities of ACTA1 gene reporter induced by RhoA, MKL1, SRF, STARS or Cytochalasin D molecule were reduced in the presence of overexpressed PAX3-FOXO1 protein. CCG-1423 is an inhibitor of RhoA-MKL1-SRF signaling, we observed there was a synergistic effect between this inhibitor and PAX3-FOXO1 to suppress ACTA1 reporter activity. Furthermore, PAX3-FOXO1 overexpression decreased ACTA1 protein level and knockdown of PAX3-FOXO1 by siRNA enhanced ACTA1 expression. In addition, both MKL1 and SRF, but not RhoA were also found to be inhibited by PAX3-FOXO1 gene at protein levels and increased once knockdown of PAX3-FOXO1 expression. The association between MKL1 and SRF in cells was decreased accordingly with ectopic expression of PAX3-FOXO1. However, the distribution of MKL1 and SRF in nuclear or cytoplasm fraction was not changed by PAX3-FOXO1 expression. Finally, we showed that ACTA1 overexpression in RH30 cells could inhibit cell proliferation and migration in vitro and impair tumor growth in vivo compared with the control groups.

Conclusions

ACTA1 is inhibited by PAX3-FOXO1 at transcription and protein levels through RhoA-MKL1-SRF signaling pathway and this inhibition may partially contribute to the tumorigenesis and development of ARMS. Our findings improved the understanding of PAX3-FOXO1 in ARMS and provided a potential strategy for the treatment of ARMS in future.

Alveolar rhabdomyosarcoma of the mandible in an adult invading the parotid gland: A rare case report

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Rhabomyosarcoma (RMS) can be localized in the cervico-facial region and in an adult.

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Its diagnosis is histological with an immunohistochemical study.

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RMS in adults require neoadjuvant chemotherapy combined with locoregional treatment by tumor excision surgery followed by radiotherapy.

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RMS of the head and neck of adults have a poor prognosis.

Introduction

Rhabdomyosarcoma (RMS) is a malignant mesenchymal neoplasm uncommon in adults.

Presentation of case

We report the case of an alveolar rhabdomyosarcoma in a rare location and in an adult. It concerns a 46-year-old woman with a mandibular location invading the parotid gland. The Immunohistochemical analysis revealed intense positivity for myogenin and desmin, favoring the diagnosis of alveolar rhabdomyosarcoma. The patient had a right hemi-mandibulectomy with parotidectomy and received chemotherapy with radiotherapy. The evolution was good up to 2 years postoperatively then the patient relapsed with a recurrence of tumour rapidly progressing and metastases in the cervical spine.

Discussion

RMS is an aggressive but rare disease that is one of the most common malignant head and neck tumors in children. The predilection sites of adult rhabdomyosarcoma are the extremities. Current treatment includes a combination of ablative surgery, chemotherapy, and radiation therapy.

Conclusion

The prognosis of head and neck rhabdomyosarcomas in adults remains very poor given the often initially advanced stage of the disease and the high metastatic potential.

Adult parameningial alveolar rhabdomyosarcoma: Case report and literature review

Alveolar rhabdomyosarcoma (ARMS) represents the most common childhood soft tissue sarcoma, but they are rarely seen among adults. Most of the protocols for adults are adapted from pediatric protocols. Here we report a case of a 53-year-old woman diagnosed with a nasal alveolar rhabdomyosarcoma, stage IV at diagnosis, treated by chemotherapy (a regimen inspired from the pediatric protocole pEpSSG RMS 2005) which led to partial response followed by chemo-radiotherapy. We performed a systematic review of adult head and neck ARMS and found 29 cases. Primary chemotherapy with different protocols (VAC, VAI or VIE) should be done followed by surgery and/or external beam radiotherapy (preferably with IMRT). EBRT seems beneficial to every ARMS with a dose around 50Gy in a conventional fractionation, eventually completed with a boost on residual tumor. The target volume must be defined on pre-chemotherapy imaging. Brachytherapy and proton therapy are under evaluation.

Intratumoral Translocation Positive Heterogeneity in Pediatric Alveolar Rhabdomyosarcoma Tumors Correlates to Patient Survival Prognosis

Alveolar rhabdomyosarcoma (ARMS) is characterized by one of three translocation states: t(2;13) (q35;q14) producing PAX3-FOXO1, t(1;13) (p36;q14) producing PAX7-FOXO1, or translocation-negative. Tumors with t(2;13) are associated with greater disease severity and mortality than t(1;13) positive or translocation negative patients. Consistent with this fact, previous work concluded that a molecular analysis of RMS translocation status is essential for the accurate determination of prognosis and diagnosis. However, despite this knowledge, most diagnoses rely on histology and in some cases utilize fluorescence in situ hybridization (FISH) probes unable to differentiate between translocation products. Along these same lines, diagnostic RT-PCR analysis, which can differentiate translocation status, is unable to determine intratumoral translocation heterogeneity, making it difficult to determine if heterogeneity exists and whether correlations exist between this heterogeneity and patient outcomes. Using newly developed FISH probes, we demonstrate that intratumoral heterogeneity exists in ARMS tumors with respect to the presence or absence of the translocation product. We found between 3 and 98% of cells within individual tumor samples contained a translocation event with a significant inverse correlation (R² = 0.66, p = 0.001) between the extent of intratumoral translocation heterogeneity and failure-free survival of patients. Taken together, these results provide additional support for the inclusion of the molecular analysis of these tumors and expand on this idea to support determining the extent of intratumoral translocation heterogeneity in the diagnosis of ARMS to improve diagnostic and prognostic indicators for patients with these tumors.

Assessing alveolar rhabdomyosarcoma cell lines as tumor models by comparison of mRNA expression profiles

Numerous cell lines for human alveolar rhabdomyosarcoma (ARMS) have been developed and are widely used to study biological processes of this myogenic cancer. The present study investigated the resemblance of commonly used ARMS cell lines to primary tumors in regards to gene expression. RNA-sequencing data was retrieved from published datasets for 4 commonly used ARMS cell lines and 35 ARMS primary tumors. The genes with most variable expression across primary tumors were used to calculate rank-based Spearman's correlation. The observed median correlations ranged from 0.36 to 0.61. RH-41 showed the highest median correlation while KYM-1 was the least correlated cell line. A significant number of genes dysregulated between tumors and non-tumors also exhibited similar expression patterns between tumors and cell lines, including The findings suggest that ARMS cell lines exhibit changes in gene expression compared to primary tumors and may not be completely representative of the disease process.

Establishment and characterization of a novel alveolar rhabdomyosarcoma cell line, NCC-aRMS1-C1

Alveolar rhabdomyosarcoma (aRMS) is a histological subtype of RMS, which is the most common pediatric and adolescent soft-tissue sarcoma, accounting for 3-4% of all pediatric malignancies. Patient-derived cells are essential tools for understanding the molecular mechanisms of poor prognosis and developing novel anti-cancer drugs. However, only a limited number of well-characterized cell lines for rhabdomyosarcoma from public cell banks is available. Therefore, we aimed to establish a novel cell line of aRMS from the tumor tissue of a patient with aRMS. The cell line was established from surgically resected tumor tissue from a 4-year-old male patient diagnosed with stage III, T2bN1M0 aRMS and was named as NCC-aRMS1-C1. The cells were maintained for more than 3 months under tissue culture conditions and passaged more than 20 times. We confirmed the presence of identical fusion gene such as PAX7-FOXO1 in both the original tumor and NCC-aRMS1-C1. The cells exhibited spheroid formation and invasion. We found that docetaxel, vincristine, ifosfamide, dacarbazine, and romidepsin showed remarkable growth-suppressive effects on the NCC-aRMS1-C1 cells. In conclusion, the NCC-aRMS1-C1 cell line exhibited characteristics that may correspond to the lymph node metastasis in aRMS and mirror its less aggressive features. Thus, it may be useful for innovative seeds for novel therapeutic strategies.

Soft Tissue Special Issue: Skeletal Muscle Tumors: A Clinicopathological Review

Skeletal muscle tumors are classified into rhabdomyoma and embryonal, alveolar, spindle cell/sclerosing and pleomorphic rhabdomyosarcoma according to WHO classifications of tumors. These tumors arise mostly in the head and neck and, in childhood, represent the largest subset of soft tissue tumors. Although these skeletal muscle tumors show common immunoexpression of two myogenic regulatory factors, MyoD1 and myogenin, their molecular biological backgrounds are quite different. Therefore, treatment regimens vary a great deal depending on the histological subtype. Histopathologically, rhabdomyoma is characterized by well-demarcated lesions with no invasion of the surrounding tissue. Embryonal rhabdomyosarcoma is composed of primitive mesenchymal cells in various stages of myogenesis and shows heterogeneous nuclear staining for myogenin. Alveolar rhabdomyosarcoma, on the other hand, shows a proliferation of uniform primitive round cells arranged in alveolar patterns. The tumor cells at the periphery of alveolar structures adhere in a single layer to the fibrous septa. Diffuse and strong nuclear immunoexpression for myogenin is observed. In genetic backgrounds, almost all alveolar rhabdomyosarcomas contain a characteristic fusion gene such as PAX3/7-FOXO1. Spindle cell/sclerosing rhabdomyosarcoma is characterized by fascicularly arranged spindle-shaped cells or dense hyalinized collagenous matrix. NCOR2- or VGLL2-related gene fusions or MYOD1 (p.L122R) mutation is commonly recognized. Epithelioid rhabdomyosarcoma is a rare variant of rhabdomyosarcoma that shows a proliferation of epithelioid tumor cells having large vesicular nuclei, prominent nucleoli, and amphophilic to eosinophilic cytoplasm arranged in sheets. As these characteristic histological and molecular features are present in each subtype, it is possible to diagnose skeletal muscle tumors accurately.

LOXL2 promotes oncogenic progression in alveolar rhabdomyosarcoma independently of its catalytic activity

Rhabdomyosarcoma (RMS) is the most common soft tissue malignancy in childhood and adolescence. Patients with the most aggressive histological variant have an unfavorable prognosis due to a high metastasis incidence. Lysyl oxidase-like 2 (LOXL2) is a lysyl oxidase, member of a family of extracellular matrix (ECM) crosslinking enzymes that recently have emerged as important regulators of tumor progression and metastasis. We report that LOXL2 is overexpressed in RMS, suggesting a potential role for LOXL2 in RMS oncogenic progression. Consistently, transient and stable LOXL2 knockdown decreased cell migratory and invasive capabilities in two ARMS cell lines. Furthermore, introduction of LOXL2 in RMS non-expressing cells using wild type or mutated (catalytically inactive) constructs resulted in increased cell migration, cell invasion and number and incidence of spontaneous lung metastasis in vivo, independently of its catalytic activity. To further study the molecular mechanism associated with LOXL2 expression, a pull-down assay on LOXL2-transfected cells was performed and analyzed by mass spectrometry. The intermediated filament protein vimentin was validated as a LOXL2-interactor. Thus, our results suggest an oncogenic role of LOXL2 in RMS by regulating cytoskeleton dynamics and cell motility capabilities.

The clinical and radiologic features of paediatric rhabdomyosarcoma

Rhabdomyosarcoma is the most common soft-tissue sarcoma in children. The most common sites are head and neck, genitourinary tract and extremities. In this review we outline the clinical and radiologic features of paediatric rhabdomyosarcoma, as well as imaging considerations and imaging of relapse.

Isolated Breast Relapse after Metastatic Alveolar Rhabdomyosarcoma in a Young Premenarcheal Girl: What Could Have Been Done?

Alveolar rhabdomyosarcoma (RMS) is one of the most common pediatric soft-tissue neoplasms. Breast involvement either as primary tumor or metastasis is extremely rare. Herein, we report a case of primary limb alveolar RMS with breast metastases in a young premenarcheal girl that relapsed only to the metastatic breast site after achieving complete response. Accordingly, we believe that investigations of the mammary glands should be part of the routine diagnostic workup in adolescent females with RMS. Local therapeutic measures to control breast disease, including surgery or radiotherapy has to be considered for better prognosis. Newer radiation modalities aiming at reducing side effects should be developed.

[Round-cell sarcomas]

Round-cell sarcomas represent highly malignant tumors that occur predominantly in children, adolescents, and young adults. Round-cell sarcomas are caused by recurrent translocations that involve certain transcription factors. Ewing's sarcoma, Ewing-like sarcomas (e.g. CIC-DUX positive or BCOR positive sarcomas), desmoplastic small round-cell tumors (DSRCTs), and alveolar rhabdomyosarcomas (ARMs) are typical examples of this particular group of sarcomas. These entities differ in their tumor genetics, which is correlated with immunohistochemical expression profiles and with clinical phenotypes. Classification should be based on molecular findings. Immunohistochemistry may serve as a surrogate marker.

Adult Alveolar Rhabdomyosarcoma on Extremity, Successful Treatment with Radiotherapy following Chemotherapy: Serial Case Report

Alveolar rhabdomyosarcoma (RMS) is one of the four subtypes of RMS. Alveolar RMS is the rare type found in adults, with the worse prognosis. We report 2 serial cases of alveolar RMS on extremity which was only treated with subtotal excision or incision biopsy. We further gave a total dose of 70 Gy radiotherapy on the local tumor and 50 Gy prophylaxis dose on regional lymph node after 6 cycles of anthracyclines-based chemotherapy. Postradiotherapy, contrast computed tomography scan revealed no tumor mass left (complete response).

Berberis orthobotrys - A promising herbal anti-tumorigenic candidate for the treatment of pediatric alveolar rhabdomyosarcoma

ETHNOPHARMACOLOGICAL RELEVANCE

Berberis orthobotrys (BORM) is a medical plant with a long history in traditional usage for the treatment of wounds, cancer, gastrointestinal malady and several other diseases. Our previous studies identified the endemic Pakistani plant Berberis orthobotrys Bien. ex Aitch. as promising source for the treatment of breast cancer and osteosarcoma.

AIM OF THE STUDY

The present study was aimed to evaluate the anti-cancer properties of 26 plant derived extracts and compounds including the methanolic root extract of Berberis orthobotrys (BORM) on pediatric alveolar rhabdomyosarcoma (RMA), which is known to develop drug resistance, metastatic invasion and potential tumor progression.

MATERIALS AND METHODS

The main anti-tumor activity of BORM was verified by focusing on morphological, cell structural and metabolic alterations via metabolic profiling, cell viability measurements, flow cytometry, western blotting and diverse microscopy-based methods using the human RMA cell line Rh30.

RESULTS

Exposure of 25 µg/ml BORM exerts an influence on the cell stability, the degradation of oncosomes as well as the shutdown of the metabolic activity of RMA cells, primarily by downregulation of the energy metabolism. Therefore glycyl-aspartic acid and N-acetyl serine decreased moderately, and uracil increased intracellularly. On healthy, non-transformed muscle cells BORM revealed very low metabolic alterations and nearly no cytotoxic impact. Furthermore, BORM is also capable to reduce Rh30 cell migration (~50%) and proliferation (induced G2/M cycle arrest) as well as to initiate apoptosis confirmed by reduced Bcl-2, Bax and PCNA expression and induced PARP-1 cleavage.

CONCLUSIONS

The study provides the first evidence, that BORM treatment is effective against RMA cells with low side effects on healthy cells.

Clinicopathologic features of 300 rhabdomyosarcomas with emphasis upon differential expression of skeletal muscle specific markers in the various subtypes: A single institutional experience

The present study was aimed at evaluating clinicopathologic and immunohistochemical (IHC) features of 300 rhabdomyosarcomas (RMSs), including differential IHC expression and prognostic value of myogenin and MyoD1 across various subtypes of RMSs. IHC expression of myogenin and MyoD1 was graded on the basis of percentage of tumor cells displaying positive intranuclear immunostaining i.e. grade 1 (1-25%); grade 2 (26-50%); grade 3 (51-76%) and grade 4 (76-100%).Clinical follow-up was available in 238 (79.3%) patients. Various clinicopathologic parameters were correlated with 3-year disease free survival (DFS) and overall survival (OS). There were 140 cases (46.7%) of alveolar RMS (ARMS), 90 of embryonal RMS (ERMS) (30%), 61 (20.3%) of spindle cell/sclerosing RMS and 9 cases (3%) of pleomorphic RMS. Most cases, barring pleomorphic RMSs, occurred in the first two decades (228 cases) (76%), frequently in males, in the head and neck region (126) (42%). By immunohistochemistry, desmin was positive in 292/299 (97.6%) tumors; myogenin in 238/267 (89.1%) and MyoD1 in 192/266 (72.2%) tumors. High myogenin expression (in ≥51% positive tumor cells) was significantly associated with ARMSs (95/121, 78.5%), as compared to other subtypes (48/117, 41%) (p value < 0.001). High MyoD1 expression (≥51% tumor cells) was seen in more cases of pure sclerosing, combined with spindle cell/sclerosing RMSs (10/10, 100%), as compared to the other subtypes (91/141, 67.4%) (p = 0.032). There was no significant difference between high myogenin expression and clinical outcomes. Patients without metastasis and harbouring tumors, measuring ≤5 cm showed a significant increase in OS, with p values = 0.01 and <0.001, respectively. ARMS was the most frequent subtype. There was a significant association between high myogenin expression and ARMSs and high MyoD1 expression and spindle cell/sclerosing RMSs. High myogenin expression did not correlate with clinical outcomes. Patients with smaller sized tumors and without metastasis had significantly better clinical outcomes.

Importance of whole-body imaging with complete coverage of hands and feet in alveolar rhabdomyosarcoma staging

BACKGROUND

Alveolar rhabdomyosarcoma commonly arises in the extremities and is characterized by aggressive biology and high frequency of metastases. Whole-body imaging is increasingly employed in pediatric oncology but not recommended as standard in the staging of soft-tissue sarcomas.

OBJECTIVE

After observing patients with a large symptomatic alveolar rhabdomyosarcoma lesion and a smaller silent lesion in the more distal part of an extremity we sought to estimate the frequency of this constellation.

MATERIALS AND METHODS

We retrospectively evaluated the data of prospectively registered paediatric patients (age <21 years) with alveolar rhabdomyosarcoma in the SoTiSaR (Soft Tissue Sarcoma Registry) of the Cooperative Weichteilsarkom Studiengruppe (CWS) 09/2011-04/2015 with regard to whole-body imaging.

RESULTS

Seventy-five patients were eligible. Images of 57 patients had been submitted for reference consultation, including 80 whole-body examinations in 36 patients. Among them were 5 patients (14%, 95% confidence interval 3-25%) who had been diagnosed because of a symptomatic lesion while an additional silent lesion in the distal part of an extremity had remained unnoticed and had only been detected by later whole-body imaging. It is noteworthy that in 42 (53%) of all 80 whole-body examinations, the hands and feet had been only partially covered or completely excluded.

CONCLUSION

In alveolar rhabdomyosarcoma silent lesions can be overlooked when the distal parts of the limbs are not thoroughly examined and not completely covered by imaging. Missing them influences treatment decisions and prognosis. Our results should be considered when evaluating the potential role of whole-body imaging in rhabdomyosarcoma.

Synchronous breast cancer and alveolar rhabdomyosarcoma bone marrow metastases

Alveolar rhabdomyosarcoma (RMS) is primarily a malignancy of childhood and adolescence. While RMS is rare in adults, the breast and the bone marrow are known but uncommon sites for metastatic disease. Bone marrow is also a known sanctuary site for metastatic breast cancer. We present the case of a woman with a remote history of breast cancer and RMS who developed anemia and thrombocytopenia of unknown etiology. Additional laboratory tests were negative for a cause; therefore, the decision was made to proceed with a bone marrow biopsy. The initial biopsy results were consistent with breast cancer metastasis. Subsequent diagnostic imaging of the breast led to biopsy of an enlarging morphologically benign breast mass, unexpectedly yielding alveolar RMS. This unanticipated diagnosis led to revaluation of the bone marrow, this time showing synchronous metastases from breast carcinoma and alveolar RMS. Imaging findings of this patient, along with literature review of RMS imaging characteristics, will be reviewed.

The tyrosine kinase inhibitor crizotinib does not have clinically meaningful activity in heavily pre-treated patients with advanced alveolar rhabdomyosarcoma with FOXO rearrangement: European Organisation for Research and Treatment of Cancer phase 2 trial 90101 'CREATE'

BACKGROUND

Alveolar rhabdomyosarcomas (ARMSs) can harbour MET and anaplastic lymphoma kinase (ALK) alterations. We prospectively assessed crizotinib in patients with advanced/metastatic ARMS.

METHODS

Eligible patients with a central diagnosis of ARMS received oral crizotinib 250 mg twice daily. Patients were attributed to MET/ALK+ or MET/ALK- subcohorts by assessing the presence or absence of the forkhead box O1 (FOXO1; a marker of MET upregulation) and/or ALK gene rearrangement. The primary end-point was the objective response rate (ORR). Secondary end-points included duration of response (DOR), disease control rate (DCR), progression-free survival (PFS), progression-free rate (PFR), overall survival (OS) and safety.

FINDINGS

Nineteen of 20 consenting patients had centrally confirmed ARMS. Molecular assessment revealed rearrangement of FOXO1 in 17 tumours and ALK in none. Thirteen eligible patients were treated, but only eight were evaluable for the primary end-point because of the observed aggressiveness of the disease. Among seven evaluable MET+/ALK- patients, only one achieved a confirmed partial response (ORR: 14.3%; 95% confidence interval [CI]: 0.3-57.8) with a DOR of 52 d. Further MET+/ALK- efficacy end-points were DCR: 14.3% (95% CI: 0.3-57.8), median PFS: 1.3 months (95% CI: 0.5-1.5) and median OS: 5.6 months (95% CI: 0.7-7.0). The remaining MET+/ALK- and MET-/ALK- patients had early progression as best response. Common treatment-related adverse events were fatigue (5/13 [38.5%]), nausea (4/13 [30.8%]), anorexia (4/13 [30.8%]), vomiting (2/13 [15.4%]) and constipation (2/13 [15.4%]). All 13 treated patients died early because of progressive disease.

INTERPRETATION

Crizotinib is well tolerated but lacks clinically meaningful activity as a single agent in patients with advanced metastatic ARMS. Assessing single agents in aggressive, chemotherapy-refractory ARMS is challenging, and future trials should explore established chemotherapy ± investigational compounds in earlier lines of treatment.

CLINICAL TRIAL NUMBER

EORTC 90101, ClinicalTrials.gov NCT01524926.

Rhabdomyosarcoma mimicking as pleural effusion

Rhabdomyosarcoma (RMS), a malignant neoplasm of skeletal muscle origin, is the most common soft tissue sarcoma caused by infectious disease etiology, especially in nondeveloped countries. Despite being a relatively rare cancer, it accounts for approximately 40% of all recorded soft tissue sarcomas. Alveolar RMSs are seen to occur in children, while around 80% cases occur in the first three decades of life. We present here, a case of a 12-year-old child having alveolar RMS, presenting clinically and radiologically with pleural effusion.

Regulatory landscape fusion in rhabdomyosarcoma through interactions between the PAX3 promoter and FOXO1 regulatory elements

Background

The organisation of vertebrate genomes into topologically associating domains (TADs) is believed to facilitate the regulation of the genes located within them. A remaining question is whether TAD organisation is achieved through the interactions of the regulatory elements within them or if these interactions are favoured by the pre-existence of TADs. If the latter is true, the fusion of two independent TADs should result in the rewiring of the transcriptional landscape and the generation of ectopic contacts.

Results

We show that interactions within the PAX3 and FOXO1 domains are restricted to their respective TADs in normal conditions, while in a patient-derived alveolar rhabdomyosarcoma cell line, harbouring the diagnostic t(2;13)(q35;q14) translocation that brings together the PAX3 and FOXO1 genes, the PAX3 promoter interacts ectopically with FOXO1 sequences. Using a combination of 4C-seq datasets, we have modelled the three-dimensional organisation of the fused landscape in alveolar rhabdomyosarcoma.

Conclusions

The chromosomal translocation that leads to alveolar rhabdomyosarcoma development generates a novel TAD that is likely to favour ectopic PAX3:FOXO1 oncogene activation in non-PAX3 territories. Rhabdomyosarcomas may therefore arise from cells which do not normally express PAX3. The borders of this novel TAD correspond to the original 5'- and 3'- borders of the PAX3 and FOXO1 TADs, respectively, suggesting that TAD organisation precedes the formation of regulatory long-range interactions. Our results demonstrate that, upon translocation, novel regulatory landscapes are formed allowing new intra-TAD interactions between the original loci involved.

Electronic supplementary material

The online version of this article (doi:10.1186/s13059-017-1225-z) contains supplementary material, which is available to authorized users.

Alveolar rhabdomyosarcoma: origin and prognostic implications of molecular findings

We present the case of a 2-year-old male patient with a facial tumor partially treated with chemotherapy before his admission to our institution. The tumor involved from the frontal region to the maxillary floor, the orbit, and the maxillary and sphenoid sinuses. The histopathological diagnosis revealed a stage IV alveolar rhabdomyosarcoma with infiltration to bone marrow and cerebrospinal fluid. He was managed with four cycles of adriamycin, actinomycin, cyclophosphamide and vincristine; cisplatin and irinotecan were added to the last cycle. The tumor had a 50% size reduction, but the patient died after a neutropenia and fever episode. The aggressive behavior of alveolar rhabdomyosarcoma has been associated with the expression of oncogenic fusion proteins resulting from chromosomal translocations, particularly t(2;13) (q35;q14) PAX3/FOXO1, and t(1;13) (p36;q14) PAX7/FOXO1 which were present in this patient.

Fusion RNA profiling provides hints on cell of origin of mysterious tumor

Biological samples can be grouped into separate clusters based on their gene expression profiles. This approach has yielded meaningful biological insights and facilitated biomarker discoveries. Recently, we developed another approach to study connections between biological samples based on their fusion RNA expression. We have used this approach to provide insights into the cell of origin for a mysterious tumor, alveolar rhabdomyosarcoma.

A clinicopathologic study of head and neck rhabdomyosarcomas showing FOXO1 fusion-positive alveolar and MYOD1-mutant sclerosing are associated with unfavorable outcome

BACKGROUND

Based on their distinctive histologic and genetic features, the latest WHO classification of soft tissue tumors includes four pathologic variants of rhabdomyosarcoma (RMS): embryonal (ERMS), alveolar (ARMS), spindle cell-sclerosing (SRMS-ScRMS) and pleomorphic RMS. The aim of this study focused on a detailed clinicopathologic and survival analysis of head and neck RMS (HNRMS) using the latest pathologic and molecular criteria reflecting this new subclassification in a large cohort.

PATIENTS AND METHODS

Patients managed for HNRMS in our institution (1996-2015) were analyzed. The presence of a FOXO1 fusion was required for the classification of ARMS. MYOD1 mutations in SRMS-ScRMS were tested when material available. Univariate and multivariate analyses were performed to evaluate variables related to overall survival (OS).

RESULTS

Ninety-nine HNRMS patients (52 males and 47 females, mean of 16years) were included in the study after pathologic re-review. The most common location was parameningeal (PM) (n=64), followed by non-orbital/non-PM (n=25) and orbital (n=10). There were 53 ERMS, 33 fusion-positive ARMS and 13 SRMS-ScRMS [SRMS (8); ScRMS (5)]. The 5-year OS rate for ERMS patients was significantly higher (82%) compared to ARMS (53%) and SRMS-ScRMS (50%) [SRMS (75%); ScRMS (30%)]. Univariate analysis showed that survival was dependent on histology (P=0.012), tumor size >5cm (P<0.001), regional lymph node involvement (P=0.002), metastasis at initial presentation (P<0.001), stage (P<0.001), and recurrence (P=0.002). Multivariate analysis confirmed histologic subtype to be significant (P=0.043).

CONCLUSION

Our findings reinforce that HNRMS is a heterogenous disease with ARMS and SRMS-ScRMS having an equally unfavorable outcome.

Resilience Through Squamous Cell Carcinoma and Rhabdomyosarcoma of Oral Cavity: A Unique Case Report

Rhabdomyosarcoma (RMS) is a soft tissue neoplasm of mesenchymal origin. It is a commonly encountered malignant tumor amongst pediatric patients, yet relatively rare in adults. It usually involves the head and neck region, genitourinary organs and retroperitoneal structures. In adults, the most commonly affected area is the head and neck region. We present here a case of a 30-year-old male patient with a primary squamous cell carcinoma of the tongue (T1, N0, M1), successfully cured with surgery and chemoradiotherapy and later on development of metachronous ipsilateral lesion on the left lower alveolus. Biopsy was consistent with spindle cell RMS. Immunohistochemistry demonstrated positivity for desmin, vimentin and myogenin, thus confirming the mesenchymal origin. With the best of our literature search, this is an exceptional case presenting two malignant lesions with diverse genetic origins, diagnosed at stage 1 and giving a favorable outcome.

RGD liposome-protamine-siRNA (LPR) nanoparticles targeting PAX3-FOXO1 for alveolar rhabdomyosarcoma therapy

Alveolar rhabdomyosarcoma (ARMS) are aggressive soft tissue tumors harboring specific fusion transcripts, notably PAX3-FOXO1 (P3F). Current therapy concepts result in unsatisfactory survival rates making the search for innovative approaches necessary: targeting PAX3-FOXO1 could be a promising strategy. In this study, we developed integrin receptor-targeted Lipid-Protamine-siRNA (LPR) nanoparticles using the RGD peptide and validated target specificity as well as their post-silencing effects. We demonstrate that RGD-LPRs are specific to ARMS in vitro and in vivo. Loaded with siRNA directed against the breakpoint of P3F, these particles efficiently down regulated the fusion transcript and inhibited cell proliferation, but did not induce substantial apoptosis. In a xenograft ARMS model, LPR nanoparticles targeting P3F showed statistically significant tumor growth delay as well as inhibition of tumor initiation when injected in parallel with the tumor cells. These findings suggest that RGD-LPR targeting P3F are promising to be highly effective in the setting of minimal residual disease for ARMS.

Alveolar rhabdomyosarcoma of maxilla

Rhabdomyosarcoma (RMS), a malignant neoplasm of skeletal muscle origin, is the most common soft tissue sarcoma seen in childhood and adolescence. The most frequent site is the head and neck accounting for 40% of all cases and other involved sites are genitourinary tract, retroperitoneum, and to a lesser extent, the extremities. RMS is relatively uncommon in the oral cavity and the involvement of the jaws is extremely rare. Here, we report a case of 50-year-old female with oral RMS involving maxillary alveolar region with clinical, radiological, histopathological and immunohistochemical findings.

Alveolar rhabdomyosarcoma confined to the bone marrow with no identifiable primary tumour using FDG-PET/CT

Background

Rhabdomyosarcoma (RMS), a malignant tumour of mesenchymal origin which can occur at various sites in the body, is one of the most common soft tissue sarcomas in both children and adolescents, but is rare in adults with a prevalence of less than 1 %. The alveolar subtype of rhabdomyosarcoma (ARMS) is typically characterized by a specific reciprocal chromosomal translocation involving the PAX3 and FKHR or PAX7 and FKHR genes, respectively. ARMS is most frequently seen in childhood, and typically affects the sinuses and soft tissue of the extremities, with approximately 23 % exhibiting metastasis to the marrow. Non-invasive F-18-fluorodeoxyglucose positron-emission tomography (FDG-PET) scans have a high ability to detect lymph nodes, bone, and bone marrow involvement in patients with metastatic RMS, often with higher sensitivity and specificity compared with conventional modalities.

Case presentation

Here, we report an unusual case of ARMS confined to the bone marrow in an older adult that lacked an identifiable primary tumour using FDG-PET/CT and mimicked a haematological disease with pancytopenia but without abnormal findings by FDG-PET/CT. The patient was initially treated with topotecan/cyclophosphamide and subsequently switched to vinorelbine. Due to severe toxicity the treatment was discontinued, however after 7-months follow-up, the patient is still alive with an improved general state of health and only a mild pancytopenia with no need for blood transfusions.

Conclusion

Rhabdomyosarcoma can be limited to the bone marrow with no identifiable primary tumour. This case shows that the use of a bone marrow biopsy in suspected malignancies affecting the bone marrow is irreplaceable.

Cryptic insertion of 3'FOXO1 into inverted chromosome arm 2q in the presence of two normal chromosome 13s and 13 small interstitial duplications in a patient with alveolar rhabdomyosarcoma

Alveolar rhabdomyosarcoma (ARMS) is a pediatric soft tissue neoplasm with a characteristic translocation, t(2;13)(q35;q14), which is detected in 70-80% of cases. This well-described translocation produces the gene fusion product PAX3-FOXO1. Cryptic rearrangements of this fusion have never before been reported in ARMS. Here we describe a patient with ARMS that showed, by fluorescence in situ hybridization and G-banded chromosomes, a cryptic insertion of 3'FOXO1 into inverted chromosome 2q. The inversion breakpoints were depicted by array comparative genomic hybridization as two small interstitial duplications, one of which involved the PAX3 gene. In addition, the array comparative genomic hybridization results revealed 1q gain, 16q loss, and 11 more small duplications, with one of them involving the FOXO1 gene. Although the pathogenesis in classic ARMS cases is thought to be driven by the 5'PAX3-3'FOXO1 fusion on derivative chromosome 13, here we report a novel cryptic insertion of 3'FOXO1 resulting in a pathogenic fusion with 5'PAX3 on inverted chromosome 2q.

Detection of common chromosomal translocations in small round blue cell pediatric tumors

BACKGROUND AND AIMS

Recurrent and specific chromosomal translocations have been described in four pediatric sarcomas belonging to the small round blue cell (SRBC) group of tumors. Identification of mRNA chimeras using RT-PCR discriminates among alveolar rhabdomyosarcoma (ARMS), Ewing's sarcoma (ES/pPNET), synovial sarcoma (SS) and desmoplastic small round cell tumor (DSRCT); however, frequencies of these translocations are variable. We present a retrospective study comparing histological examination and occurrence of major chromosomal translocations to validate the diagnosis and to assess the frequency of these molecular markers in a group of 92 small round blue cell (SRBC) tumor samples from Hospital Infantil de Mexico.

METHODS

We tested a panel of RT-PCR assays to each RNA tumor sample from formalin-fixed, paraffin-embedded tumors to detect specific mRNA chimeras in 47 ES/pPNET, 19 ARMS, four SS, three DSRCT, and 19 other SRBC tumors.

RESULTS

After excluding poor RNA quality samples, we found translocations in 17/31 ES/pPNET (54.8%), 10/19 ARMS (52.6%), 4/4 SS (100%) and 4/4 DSRCT (100%). We found disagreement in only three samples: one ES/pPNET and one embryonal rhabdomyosarcoma harbor a PAX3-FOXO1 translocation (for ARMS), and one neuroepithelioma harboring a EWS-WT1 (for DSRCT). Unsuitable RNA was found in 20/92 samples (21.7%) and was related to necrosis, small amount of tumor tissue, and use of nitric acid in bone biopsies, but was not related to age of the block.

CONCLUSIONS

We found a significantly lower occurrence of chromosomal translocations in ES/pPNET compared to reports from other groups. Differences may exist in the frequencies of these molecular markers among different populations.

State of the art in oncology: high risk neuroblastoma, alveolar rhabdomyosarcoma, desmoplastic small round cell tumor, and POST-TEXT 3 and 4 hepatoblastoma

Despite advances in the treatment of pediatric cancers during the past few decades, high-risk neuroblastoma, alveolar rhabdomyosarcoma, desmoplastic small round cell tumor, and hepatoblastomas with 3 or 4 sector involvement after chemotherapy continue to present significant challenges. This review summarizes recent research on the management of these diseases, with a special focus on the use of surgical debulking, genetic analysis, immunotherapy, and chemotherapy in improving outcomes of patients with these solid tumors.

Nasopharyngeal alveolar rhabdomyosarcoma expressing CD56: a mimicker of extranodal natural killer/T-cell lymphoma

Alveolar rhabdomyosarcoma (ARMS) is remarkably rare in adults older than 45 years. Histologically, the tumor is composed of blue round cells with frequent expression of CD56 in addition to myogenic markers. Recent studies of ARMS have shown two specific recurrent translocations: PAX3-FKHR [t(2;13)(q35;q14)] or PAX7-FKHR [t(1;13)(p36;q14)]. Extranodal natural killer (NK)/T-cell lymphoma (ENKTL) occurs most frequently in the upper aerodigestive tract with a male preference in East Asia and Central and South Americas with neoplastic cells frequently expressing CD56. We report a 53-year-old Taiwanese man presenting with a nasopharyngeal mass, cervical lymphadenopathy, and multiple bone metastases. Histologically, the nasopharyngeal biopsy revealed diffuse sheets of small blue round tumor cells without obvious alveolar pattern, angioinvasion or tumor necrosis. An initial erroneous diagnosis of ENKTL was made due to CD56 expression using fresh tumor tissue with flow cytometric analysis and the patient was treated accordingly. Retrospective study showed that the tumor cells expressed CD56, desmin, and myogenin. Fluorescence in situ hybridization revealed that the tumor cells were positive for FKHR gene rearrangement, confirming the diagnosis of ARMS. Our case illustrates that a diagnosis of ENKTL based solely on CD56 expression can be misleading for a nasopharyngeal small blue round cell tumor. ARMS should be included as a differential diagnosis, and a correct diagnosis can be reached only after a high index of suspicion and a thorough histological examination with the aid of ancillary studies.

Rare adult masseteric rhabdomyosarcoma and a review of the literature

BACKGROUND

Rhabdomyosarcomas (RMSs) are a group of soft-tissue malignant tumors which derive from primitive skeletal muscle tissue that mainly affect children and adolescents. RMSs are very rare in adults, where they are usually located in the extremities.

CASE PRESENTATION

A previously healthy 32-year-old male presented at our ENT (ear, nose and throat) outpatient clinic after experiencing a parotid region swelling for 2 months. The patient was treated surgically by excising the mass and by modified radical ipsilateral neck dissection. Histological and immunohistochemical examination indicated masseteric alveolar RMS with lymphatic metastasis. The patient received radiochemotherapy, and he is still alive with no evidence of disease spread 1 year after diagnosis.

CONCLUSION

This is the first case of a masseter alveolar RMS to be reported in the literature in a patient older than 25 years; it highlights the broad spectrum of neoplasms that cause parotid region swellings and the importance of considering rare tumors during differential diagnosis.

Simultaneous targeting of insulin-like growth factor-1 receptor and anaplastic lymphoma kinase in embryonal and alveolar rhabdomyosarcoma: a rational choice

BACKGROUND

Rhabdomyosarcoma (RMS) is an aggressive soft tissue tumour mainly affecting children and adolescents. Since survival of high-risk patients remains poor, new treatment options are awaited. The aim of this study is to investigate anaplastic lymphoma kinase (ALK) and insulin-like growth factor-1 receptor (IGF-1R) as potential therapeutic targets in RMS.

PATIENTS AND METHODS

One-hundred-and-twelve primary tumours (embryonal RMS (eRMS)86; alveolar RMS (aRMS)26) were collected. Expression of IGF-1R, ALK and downstream pathway proteins was evaluated by immunohistochemistry. The effect of ALK inhibitor NVP-TAE684 (Novartis), IGF-1R antibody R1507 (Roche) and combined treatment was investigated by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assays in cell lines (aRMS Rh30, Rh41; eRMS Rh18, RD).

RESULTS

IGF-1R and ALK expression was observed in 72% and 92% of aRMS and 61% and 39% of eRMS, respectively. Co-expression was observed in 68% of aRMS and 32% of eRMS. Nuclear IGF-1R expression was an adverse prognostic factor in eRMS (5-year survival 46.9 ± 18.7% versus 84.4 ± 5.9%, p=0.006). In vitro, R1507 showed diminished viability predominantly in Rh41. NVP-TAE684 showed diminished viability in Rh41 and Rh30, and to a lesser extent in Rh18 and RD. Simultaneous treatment revealed synergistic activity against Rh41 and Rh30.

CONCLUSION

Co-expression of IGF-1R and ALK is detected in eRMS and particularly in aRMS. As combined inhibition reveals synergistic cytotoxic effects, this combination seems promising and needs further investigation.

Dense pattern of embryonal rhabdomyosarcoma, a lesion easily confused with alveolar rhabdomyosarcoma: a report from the Soft Tissue Sarcoma Committee of the Children's Oncology Group

OBJECTIVES

To examine whether the frequency of fusion-negative alveolar rhabdomyosarcoma (ARMSn) increased coincident with changes in the definition of alveolar histology.

METHODS

We re-reviewed alveolar rhabdomyosarcoma (ARMS) in the Children's Oncology Group study D9803, comparing histopathology with fusion status.

RESULTS

Our review of 255 original ARMS cases (compared with a control group of 38 embryonal rhabdomyosarcomas [ERMS] cases) revealed that many had an ARMS-like densely cellular pattern with cytologic features and myogenin expression more typical of ERMS. Following re-review, 84 (33%) cases of original ARMS were rediagnosed as ERMS. All reclassified ERMS, including dense ERMS, were fusion negative, whereas 82% of confirmed ARMS cases were fusion positive. Total ARMS diagnoses returned to historic rates of 25% to 30% of all rhabdomyosarcomas, and ARMSn decreased from 37% to 18% of ARMS cases. The outcome of reclassified ERMS was similar to confirmed ERMS.

CONCLUSIONS

To address the role of fusion status in risk stratification, pathologists should include both a histologic diagnosis and an evaluation of fusion status for all new ARMS diagnoses.

Cytological diagnosis of metastatic alveolar rhabdomyosarcoma in the ascitic fluid: Report of a case highlighting the diagnostic difficulties

Alveolar rhabdomyosarcoma is an uncommon tumor affecting adolescents and young adults that is only rarely encountered in body fluid cytology. We report the cytological features of metastatic alveolar rhabdomyosarcoma in the ascitic fluid of a 17-year-old female patient, who had presented with abdominal distention, 21 months after being diagnosed with perirectal alveolar rhabdomyosarcoma. The rare single neoplastic cells that were admixed with abundant reactive mesothelial cells were initially misinterpreted as reactive mesothelial cells. However, their neoplastic nature was established after a careful review of their cytological features and the performance of immunoperoxidase stains. Compared to the reactive mesothelial cells that were present in the sample, the malignant cells were smaller, with less ample and more homogenous cytoplasm. They had slightly larger, more hyperchromatic, and more frequently eccentric nuclei, with larger nucleoli. This case highlights the potential pitfall of the misinterpretation of metastatic alveolar rhabdomyosarcoma cells for reactive mesothelial cells. Awareness of this potential diagnostic problem and recognition of the cytomorphological features of this neoplasm in the body fluids allows the identification of malignant cells, even when they are rare and intimately associated with mesothelial cells.

Fine needle aspiration cytology of metastatic alveolar rhabdomyosarcoma

Rhabdomyosarcoma (RMS) is an aggressive malignant soft tissue tumor that arises from primitive striated muscle cells called rhabdomyoblasts. RMS is a rare tumor in adults, and involvement of the sinonasal area is extremely rare, comprising only 1.5% of all reported head and neck RMSs. Alveolar RMS, mainly seen in adults, has the worst prognosis. Incidence of lymph node metastases is more common in this type compared with the other forms. Fine needle aspiration cytology (FNAC) has been used extensively in the diagnosis of metastatic malignancies. However, metastatic soft tissue sarcomas are often overlooked, primarily due to the low frequency with which they occur. Here, we report a rare case of metastatic alveolar RMS in the cervical lymph nodes of an 18-year-old girl that was detected by FNAC. After 6 months, the patient came with a huge mass involving the nasal vestibule and the upper lip. Histology of both the main mass and the lymph nodes revealed alveolar RMS.

Rhabdomyosarcoma of the oral cavity: a case report

Rhabdomyosarcoma (RMS), a tumor of skeletal muscle origin, is the most common soft tissue sarcoma encountered in childhood and adolescence. The common sites of occurrence are the head and neck region, genitourinary tract, retroperitonium, and, to a lesser extent, the extremities. In the head and neck region, the most commonly affected sites are the orbit, paranasal sinuses, soft tissues of the cheek, and the neck. RMS is relatively uncommon in the oral cavity, and the involvement of the jaws is extremely rare. Here, we report a case of oral RMS in a 13-year-old child and describe the clinical, radiological, histopathological, and immunohistochemical findings.