Sclerosing spindle cell rhabdomyosarcoma in an adult: report of a new case and review of the literature

Transcriptional activation of PINK1 by MyoD1 mediates mitochondrial homeostasis to induce renal calcification in pediatric nephrolithiasis

This study aims to uncover the molecular mechanisms underlying pediatric kidney stone formation induced by renal calcium deposition by utilizing high-throughput sequencing data to reveal the regulation of PINK1 by MyoD1. We performed transcriptome sequencing on peripheral blood samples from healthy children and children with kidney stones to obtain differentially expressed genes (DEGs). Genes related to mitochondrial oxidative stress were obtained from the Genecards website and intersected with DEGs to obtain candidate target genes. Additionally, we conducted protein-protein interaction (PPI) analysis using the STRING database to identify core genes involved in pediatric kidney stone disease (KSD) and predicted their transcription factors using the hTFtarget database. We assessed the impact of MyoD1 on the activity of the PINK1 promoter using dual-luciferase reporter assays and investigated the enrichment of MyoD1 on the PINK1 promoter through chromatin immunoprecipitation (ChIP) experiments. To validate our hypothesis, we selected HK-2 cells and established an in vitro kidney stone model induced by calcium oxalate monohydrate (COM). We evaluated the expression levels of various genes, cell viability, volume of adherent crystals in each group, as well as mitochondrial oxidative stress in cells by measuring mitochondrial membrane potential (Δψm), superoxide dismutase (SOD) activity, reactive oxygen species (ROS), and malondialdehyde (MDA) content. Mitochondrial autophagy was assessed using mtDNA fluorescence staining and Western blot analysis of PINK1-related proteins. Apoptosis-related proteins were evaluated using Western blot analysis, and cell apoptosis was measured using flow cytometry. Furthermore, we developed a rat model of KSD and assessed the expression levels of various genes, as well as the pathologic changes in rat renal tissues using H&E and von Kossa staining, transmission electron microscopy (TEM), and the expression of creatinine, blood urea nitrogen, neutrophil gelatinase-associated lipocalin (NGAL), and kidney injury molecule-1 (KIM-1) to evaluate the mitochondrial oxidative stress in vivo (through measurement of Δψm, SOD activity, ROS, and MDA content). Mitochondrial autophagy was evaluated by Western blot analysis of PINK1-associated proteins. Apoptosis-related proteins were detected using Western blot analysis, and cellular apoptosis was examined using cell flow cytometry and TUNEL staining. Bioinformatics analysis revealed that the PINK1 gene is upregulated and vital in pediatric kidney stone patients. Our in vitro and in vivo experiments demonstrated that silencing PINK1 could inhibit kidney stone formation by suppressing mitochondrial oxidative stress both in vitro and in vivo. We identified MyoD1 as an upstream transcription factor of PINK1 that contributes to the occurrence of pediatric kidney stones through the activation of PINK1. Our in vivo and in vitro experiments collectively confirmed that silencing MyoD1 could inhibit mitochondrial oxidative stress, mitochondrial autophagy, and cellular apoptosis in a rat model of kidney stones by downregulating PINK1 expression, consequently suppressing the formation of kidney stones. In this study, we discovered that MyoD1 may promote kidney stone formation and development in pediatric patients by transcriptionally activating PINK1 to induce mitochondrial oxidative stress.

Epithelioid and spindle rhabdomyosarcoma with TFCP2 rearrangement in abdominal wall: a distinctive entity with poor prognosis

BACKGROUND

Epithelioid and spindle rhabdomyosarcoma (ES-RMS) with TFCP2 rearrangement is a recently discovered rare variant of rhabdomyosarcoma composed of epithelioid and spindle cells, because it shows extraordinarily adverse prognosis and is easily misdiagnosed as other epithelioid or spindle cell tumors.

METHODS

A rare case of ES-RMS with TFCP2 rearrangement was presented and English literatures in Pubmed online up to 01 July 2022 were gathered by two authors for a systematic review according to the inclusion and exclusion criteria.

CASE PRESENTATION/RESULTS

We report a case of ES-RMS in an early 30s-years-old female, the neoplastic cells are remarkably immunoreactive with CK(AE1/AE3), and partially with ALK protein. Unexpectedly, the tumor shows TFCP2 rearrangement with coexistence of increased copy numbers of EWSR1 and ROS1 gene and MET gene mutation. Besides, Next-generation sequencing for genetic mutational profiling revealed frequent MET exon14 mutations in chromosome 7, most of which are C > T nonsynonymous SNV, and exon42 of ROS1 in chromosome 6 showed frequent G > T mutation up to 57.54%. In addition, neither MyoD1 mutation nor gene fusions were detected. Moreover, the patient shows high tumor mutational burden (TMB) up to 14.11 counts/Mb. Finally, as many cases of ES-RMS including our case had local progression or metastasis, we find, similar to epithelioid rhabdomyosarcoma (median survival time is 10 month), ES-RMS shows a more aggressive behavior and adverse prognosis (median survival time is 17 month) than spindle cell/sclerosing rhabdomyosarcoma (median survival time is 65 month) according previous studies.

CONCLUSIONS

ES-RMS with TFCP2 rearrangement is a rare malignant tumor and easily confused with other epithelioid or spindle cell tumors, it may harbor additional gene alteration in addition to TFCP2 rearrangement, such as MET mutation, increased copy numbers of EWSR1 and ROS1 gene, high TMB. Most importantly, it may show very poor outcome with extensive metastasis.

Genetic Characterization, Current Model Systems and Prognostic Stratification in PAX Fusion-Negative vs. PAX Fusion-Positive Rhabdomyosarcoma

Rhabdomyosarcoma (RMS) is the most common soft tissue sarcoma in children and adolescents and accounts for approximately 2% of soft tissue sarcomas in adults. It is subcategorized into distinct subtypes based on histological features and fusion status (PAX-FOXO1/VGLL2/NCOA2). Despite advances in our understanding of the pathobiological and molecular landscape of RMS, the prognosis of these tumors has not significantly improved in recent years. Developing a better understanding of genetic abnormalities and risk stratification beyond the fusion status are crucial to developing better therapeutic strategies. Herein, we aim to highlight the genetic pathways/abnormalities involved, specifically in fusion-negative RMS, assess the currently available model systems to study RMS pathogenesis, and discuss available prognostic factors as well as their importance for risk stratification to achieve optimal therapeutic management.

Combined Sclerosing and Spindle Cell Rhabdomyosarcoma in Previous Craniotomy Site: A Case Report and a Review of the Literature

Sclerosing rhabdomyosarcoma (RMS) is a rare subtype of RMS with unique prominent stromal hyalinization and a pseudovascular architecture. It overlaps morphologically with spindle cell RMS and poses both diagnostic and therapeutic challenges because of its rarity and aggressive clinical course. In this article, we report a case of sclerosing RMS arising from a prior craniotomy site, which demonstrated both sclerosing and spindle cell components. A literature review of RMS with sclerosing morphology identified 122 cases. Our review documents the following: sclerosing RMS occurs in both childhood and adult populations, has a predilection for the head and neck areas, and has a worse prognosis in adults. Sclerosing RMS harbors a high frequency of MYOD1 mutations, conferring a poor clinical outcome. Sclerosing RMS and spindle RMS likely represent a morphologic spectrum of one entity.

Spindle cell/sclerosing rhabdomyosarcoma with intracranial invasion without destroying the bone of the skull base: a case report and literature review

Spindle cell/sclerosing rhabdomyosarcoma (ssRMS) is a new subtype of rhabdomyosarcoma included in the World Health Organization soft tissue and bone tumor classification in 2013. Despite the increasing number of reported cases of ssRMS, the imaging characteristics of ssRMS are not established. Herein, we present the case of an elderly Japanese woman with ssRMS of the masticator space with intracranial invasion without destruction of the adjacent bone. Attention should be paid to the presence of intracranial infiltration that may indicate a worse prognosis. Tumor growth without bone destruction could be a key finding to differentiate ssRMSs from conventional subtypes of rhabdomyosarcoma.

Histopathological, immunohistochemical and molecular cytogenetic analysis of 21 spindle cell/sclerosing rhabdomyosarcomas

Recently, spindle cell/sclerosing rhabdomyosarcoma (RMS) has been recognized as another distinct variant of a RMS. We evaluated clinicopathological features of 21 cases of spindle cell and sclerosing RMS and performed fluorescent in situ hybridization (FISH) testing in 10 (47.6%) tumours. Twenty-one tumours occurred in 16 males and 5 females (mean age, 19.7 years); commonly in the head and neck region (8) (38%) and extremities (7) (33.3%), followed by paratesticular region (2) (9.5%), chest wall (1), abdomen (1), pelvis (1) and paraspinal region (1). Average tumour size was 7.9 cm. Histopathologically, tumours that were spindle cell type (8) (38%) mostly occurred in the head and neck region, while sclerosing type (10) (47.6%) mostly occurred in the extremities. Remaining three (14.2%) tumours were mixed (sclerosing with spindle cell type). Tumour areas resembling embryonal RMS (ERMS) and alveolar RMS (ARMS) were noted in eight and three tumours respectively. Immunohistochemically, tumour cells were positive for desmin (21/21) (100%), MyoD1 (19/19) (100%), myogenin (13/15) (86.6%), SMA (2/3) and MIC2 (1/8) (12.5%). On FISH testing, none of the 10 tumours exhibited RMS1 (PAX3-FOXO1) or RMS 2 (PAX7-FOXO1) fusion. Eighteen patients underwent surgical resection and were offered adjuvant chemotherapy (CT) (4 cases), adjuvant CT + radiotherapy (RT) (4 cases) and adjuvant RT (1 case). Two patients underwent CT and a single patient received CT + RT. On follow-up (16 cases) (2-36 months), six tumours recurred and nine metastasized. Spindle/sclerosing RMSs are aggressive tumours and occur commonly in the head and neck and extremity sites. These tumours are histopathologically interrelated. Their immunohistochemical and cytogenetic profile is closer to ERMS than ARMS.

Sclerosing rhabdomyosarcoma: presentation of a rare sarcoma mimicking myoepithelial carcinoma of the parotid gland and review of the literature

Sclerosing rhabdomyosarcoma (SRMS), a recently characterized variant of rhabdomyosarcoma, can pose a significant diagnostic challenge given its rarity and its histological similarity to other malignancies. SRMS is characterized by dense hyalinized or sclerosing collagenous matrix and a pseudovascular pattern of growth. SRMS shares histologic similarities with several mesenchymal tumors including: leiomyosarcoma, osteosarcoma, chondrosarcoma, angiosarcoma, and sclerosing epithelioid fibrosarcoma. We herein report a case of SRMS mimicking a myoepithelial carcinoma of the parotid gland. The tumor contained small, spindled, and epithelioid tumor cells lining pseudovascular spaces within a dense hyalinized stroma. Initial stains for keratins, S100 and p63 were negative. However the tumor cells showed desmin and myogenin positivity. The tumor was negative for FKHR gene rearrangements and showed no MDM2 gene amplification. This is the second case of SRMS to be diagnosed in the parotid gland highlighting the potential for misdiagnosis as a primary salivary gland epithelial malignancy.

Sclerosing rhabdomyosarcoma of a chest wall in an adult: a case report and review of the literature

Sclerosing rhabdomyosarcoma (SRMS) is a newly recognized and rare variant of rhabdomyosarcoma. This soft tissue tumor has not yet been reported as a thoracic lesion. We report a case of a 26-year-old woman who presented with a large chest wall tumor. The tumor originated from the right anterior chest wall and protruded into the intra- and extrapleural cavity. A transcutaneous needle biopsy revealed spindle cells in an abundant hyalinized and fibrous stroma. Although the tumor was considered as a malignant soft-tissue neoplasm, a definitive diagnosis could not be established. A wide excision of the chest wall including the second, third and fourth rib and a part of sternum was performed. Histologically, cytoplasmic cross-striations were found in a portion of the tumor cells. The tumor cells were positive for muscle markers, and the tumor was diagnosed as rhabdomyosarcoma consistent with a sclerosing type of rhabdomyosarcoma. Eighteen months after the complete resection, the patient has pleural disseminations but is alive and undergoing chemotherapy. This case highlights the histologic features of a rare form of rhabdomyosarcoma, and emphasizes the importance of awareness of its existence and the utility of skeletal muscle markers in distinguishing sclerosing rhabdomyosarcoma from its mimics.

Sclerosing rhabdomyosarcoma presenting in the masseter muscle: a case report

Abstract

Sclerosing rhabdomyosarcoma (SRMS) is exceedingly rare, and may cause a great diagnostic confusion. Histologically, it is characterized by abundant extracellular hyalinized matrix mimicking primitive chondroid or osteoid tissue. So, it may be easily misdiagnosed as chondrosarcoma, osteosarcoma, angiosarcoma and so on. Herein, we report a case of SRMS occurring in the masseter muscle in a 40-year-old male. The tumor showed a diverse histological pattern. The tumor cells were arranged into nests, cords, pseudovascular, adenoid, microalveoli and even single-file arrays. Immunostaining showed that the tumor was positive for the Vimentin, Desmin and MyoD1, and was negative for CK, P63, NSE, CD45, CD30, S-100, CD99, Myoglobin, CD68, CD34, CD31, and α–SMA. Based on the morphological finding and immunostaining, it was diagnosed as a SRMS. In addition, focally, our case also displayed a cribriform pattern resembling adenoid cystic carcinoma. This may represent a new histological feature which can broaden the histological spectrum of this tumor and also may lead to diagnostic confusion.

Virtual slides

The virtual slide(s) for this article can be found here: http://www.diagnosticpathology.diagnomx.eu/vs/1615846455818924

Sclerosing rhabdomyosarcoma: report of a case arising in the head and neck of an adult and review of the literature

Sclerosing rhabdomyosarcoma is a unique rhabdomyosarcoma variant, characterized by a prominent hyalinizing matrix. A notable pitfall is the potential for the unusual matrix and often pseudovascular growth pattern of this lesion to lead to confusion with other sarcoma types, including osteosarcoma, chondrosarcoma, and angiosarcoma. Here we report a case of sclerosing rhabdomyosarcoma arising in a 40-year old male. The tumor was centered in the pterygomaxillary fossa with extensive infiltration into adjacent structures. Fine needle aspiration yielded a preliminary diagnosis of high-grade pleomorphic undifferentiated sarcoma, for which he received neoadjuvant chemotherapy and surgical resection. Microscopic examination showed a malignant spindled to round cell neoplasm with prominent osteoid-like, hyaline stroma. Focal rhabdomyoblastic differentiation and diffuse immunoreactivity for desmin and myogenin aided in diagnosis. Nineteen months status post primary resection, the patient expired with multiple lung and bony metastases. Among 39 cases reported thus far (including the present case), there is a broad age range (0.3-79 years), with an average age at presentation of 27 years. The most commonly involved sites are the extremities (n = 19) and head and neck (n = 15). Most cases have been treated by resection, often combined with radiation and/or chemotherapy. Out of 31 cases with follow-up information provided, 6 patients developed local recurrence, 7 patients developed regional or distant metastasis, and 5 patients died of disease. Herein we discuss the ongoing controversy regarding how sclerosing rhabdomyosarcoma might best fit into existing rhabdomyosarcoma classification schemes, based upon current clinicopathologic and molecular genetic evidence.

Testicular fusocellular rhabdomyosarcoma as a metastasis of elbow sclerosing rhabdomyosarcoma: A clinicopathologic, immunohistochemical and molecular study of one case

Sclerosing rhabdomyosarcoma (SRMS) is an infrequent variant of rhabdomyosarcoma characterized by extensive intercellular hyaline fibrosis. We report the case of a 37 year-old male with a 9 x 6 cm SRMS on the right elbow. Histologically, the tumor showed an abundant extracellular hyaline matrix with extratumoral vascular emboli and microscopic foci of fusocellular embryonal rhabdomyosarcoma (FRMS) separated by a fibrotic band from the sclerosing areas. One year later the patient presented with a right intratesticular tumor of 1.2 x 0.8 cm, which was reported as pure FRMS. Immunohistochemically, SRMS was positive only for MyoD1 and Vimentin and negative for Myogenin and Desmin. Both the elbow emboli with the extratumoral foci of FRMS and the intratesticular tumor were positive for Myogenin, MyoD1, Vimentin and Desmin. Using fluorescent in situ hybridization (FISH), the SRMS and the FRMS tumor cells of the elbow and the FRMS tumor cells of the testis were found to be negative for FOXO1A translocation in chromosome 13. PCR chimeric transcriptional products PAX3-FKHR and PAX7-FKHR were not found. Six months following testicular resection, the patient died of multiple metastases in the mediastinum, lung and right thigh.