The 2020 WHO Classification of Tumors of Soft Tissue: Selected Changes and New Entities

Primary mediastinal Ewing's sarcoma presenting with sudden and severe chest pain: a case report

Ewing's sarcoma, characterized by small round cell morphology, is a rare malignancy, with mediastinal Ewing's sarcoma being even less common. This case describes a distinctive presentation of primary mediastinal Ewing's sarcoma in a 32-year-old male presenting with sudden and severe chest pain. Initial evaluation excluded cardiac and pulmonary emergencies, revealing a posterior mediastinal mass through advanced imaging. The patient's clinical symptoms significantly improved following the complete resection of the tumor via thoracoscopy. Subsequent analysis incorporating imaging, histological, immunohistochemical and genetic findings led to the conclusive diagnosis of primary mediastinal Ewing's sarcoma.

[Chest wall reconstruction with a non-rigid synthetic rib prosthesis: a multicenter study]

Chest wall resection is performed for a variety of diseases, for primary rib and soft tissue tumors, metastatic lesions, or locally invasive growth of lung and mediastinal tumors being the most common indications. Following the resection phase, it is essential to determine the method of chest wall reconstruction that will restore the structural function, preserve pulmonary biomechanics, reduce the likelihood of residual pleural space, pulmonary hernia, and protect intrathoracic organs. The main objective of this study is to investigate the outcomes of chest wall resection with reconstruction using Codubix material.

MATERIAL AND METHODS

This retrospective multicenter study included 22 patients who underwent chest wall tumor resection with subsequent Codubix rib endoprosthesis reconstruction from 2019 to 2023. Four medical institutions participated in the study: P.A. Herzen Moscow Cancer Research Institute, Sverdlovsk Regional Oncology Hospital, Morozov Children's City Clinical Hospital and Kaluga Regional Oncology Hospital. Inclusion criteria were the presence of chest wall tumors, both primary and secondary, removal of more than 2 ribs, resection of the rib arch and the sternum.

RESULTS

The median age was 60 years (48-66), 11 (50%) patients were females and 11 (50%) males. Operations for chest wall sarcoma, metastatic lesions, and lung cancer were performed in 9 (40.9%), 4 (18.2%), and 3 (13.6%) patients, respectively. The median number of removed ribs was 3 (2-4), with a maximum of 7. Sternotomy was performed in 9 (40.9%) patients, and subtotal resection of the body or handle of the sternum was carried out in 77.7%. Combined resections were performed in 14 (63.6%) patients. Radical tumor removal (R0) was achieved in 21 (95.5%) patients. Complications were observed in 9 (40.9%) patients, with intermuscular seroma being the most common in three (33.3%), followed by hydrothorax in 2 (22.2%), bilateral pneumonia, acute respiratory failure, and postoperative delirium in 1 (11.1%) patient each. One patient had the Codubix plate removed due to postoperative wound infection. The median overall and recurrence-free survival was not reached, and the 1-year recurrence-free survival was 63.9%, with an overall survival of 86.8%.

CONCLUSION

Reconstruction with Codubix material allows for satisfactory functional and cosmetic results, characterized by a low complication rate and good adaptive properties.

Update of cartilaginous tumours according to the WHO classification 2020

Cartilaginous tumours are a large and heterogeneous group of neoplasms characterised by the presence of a chondroid matrix, with lobular growth and arcuate, ring-like or popcorn-like calcification patterns. MRI shows hyperintensity in T2-weighted sequences and a lobulated or septal relief in postcontrast images. In the WHO 2020 classification, chondral tumours are classified as benign, intermediate or malignant. Despite technological advances, they continue to pose a challenge for both the radiologist and the pathologist, being the main difficulty the differentiation between benign and malignant tumours, which is why they require a multidisciplinary approach. This paper describes the main changes introduced in the 2020 update, describes the imaging characteristics of the main cartilaginous tumours and provides the radiological keys to differentiate between benign and malignant tumours.

Denosumab Induces Neoplastic Stromal Cell Apoptosis Via p62 Downregulation Dependent on Autophagy Pathway in Giant Cell Tumour of Bone

BACKGROUND

As the only humanized monoclonal antibody against receptor activator of nuclear factor-κB ligand (RANKL) for giant cell tumour of bone (GCTB) therapy, denosumab has limited antitumour effect on neoplastic stromal cells. Nevertheless, its mechanism of action has not yet been clarified. A previous study has revealed that p62 may play an important role in the antitumour activity of denosumab.

OBJECTIVE

The study aimed to investigate if the mechanism by which denosumab inhibits GCTB neoplastic stromal cells growth is via p62 modulation and other related mechanisms.

METHODS

p62 expression before and after denosumab therapy was analysed by RT‒qPCR, western blot, ELISA, and immunohistochemical assays. Two primary neoplastic stromal cells were isolated from fresh GCTB tumour tissue (L cell) and metastatic tissue (M cell). Cell proliferation, migration, apoptosis, and autophagy were investigated in p62 knockdown neoplastic stromal cells transfected by short hairpin RNA lentivirus in vitro. Tumor growth was evaluated in the chick chorioallantoic membrane model in vivo.

RESULTS

p62 expression was found to be downregulated following denosumab therapy. The patients with a decrease in p62 expression had lower recurrence-free survival rates. The proliferation of M cells was not inhibited by denosumab therapy, but it was restored by p62 knockdown. Moreover, p62 knockdown inhibited tumour growth in vivo. Denosumab induced M cell apoptosis and arrested the cell cycle at the G1/G0 transition and these effects were also enhanced by p62 knockdown. Autophagic flux assays revealed p62 modulation to be dependent on autophagy following denosumab incubation.

CONCLUSION

Denosumab induced neoplastic stromal cells apoptosis via p62 downregulation dependent on autophagy pathway. The combination of p62 and RANKL knockdown might be a better strategy than RANKL knockdown alone for GCTB targeted therapy.

PROGNOSTIC IMPLICATIONS OF PD-L1 EXPRESSION AND LOSS OF PTEN IN PATIENTS WITH RHABDOMYOSARCOMA, EWING'S SARCOMA AND OSTEOSARCOMA

BACKGROUND

In children, osteosarcoma (OS), Ewing's sarcoma (ES), and rhabdomyosarcoma (RMS) are the most common sarcomas. A link between the anti-programmed death ligand-1 PD-L1 and the tumor suppressor phosphatase and tensin homologue (PTEN) expression has been described in many tumors. The aim of this work is to determine clinicopathological relationships and the possible prognostic significance of PD-L1 and PTEN expression in rhabdomyosarcoma (RMS), Ewing's sarcoma (ES), and osteosarcoma (OS).

MATERIALS AND METHODS

Expression of PD-L1 and PTEN were examined by immunohistochemistry in 45 archival RMS, ES, and OS cases.

RESULTS

The positive expression of PD-L1 was found in 16.7% and 31.6% of ES and OS, respectively. The negative PD-L1 was related to a substantially longer survival in ES cases (p = 0.045), but positive PD-L1 expression was significantly associated with the increased tumor stage and vascular invasion in the OS cases (p = 0.005 and p = 0.002), respectively. On the other hand, PTEN loss was strongly associated with deep tumor, high tumor grade, and recurrence in RMS (p = 0.002, p = 0.045, and p = 0.026, respectively). However, PTEN loss was significantly absent in ES as tumor grade increased (p = 0.031). It is noteworthy that tumor recurrence, the loss of PTEN, and positive PD-L1 were all considered predictive factors in OS patients (p = 0.045, p = 0.032, and p = 0.02, respectively).

CONCLUSIONS

In children, OS and ES have positive PD-L1 expression, which has an independent unfavorable prognostic effect and raises the possibility of using PD-L1 as a therapeutic target. OS, ES, and RMS prognosis are all predicted by PTEN loss.

Case Report: Colon malignant tumor caused by retroperitoneal small round cell undifferentiated sarcoma

Small round cell undifferentiated sarcoma is a rare and highly invasive group of malignant bone and soft tissue tumors, often associated with a high misdiagnosis rate. The patient in this case was a 34-year-old male who presented with a two-month history of abdominal pain that worsened over the past two weeks. Elevated levels of tumor markers CA19-9 and CA72-4 were observed. Imaging revealed a substantial, well-vascularized mass in the lower left abdomen, located in the posterior abdominal cavity, invading the descending colon and the root of the small mesentery, and infiltrating the serous layer. The lesion was extensively resected without any postoperative complications. Microscopic examination indicated a combination of mucinous adenocarcinoma (approximately 30%) and small round cell undifferentiated sarcoma (approximately 70%). The patient was followed up for six months, and one month after surgery, a recurrence of the tumor was observed in the left paracolonic sulcus area, with metastases to the abdominal wall, peritoneum, and medial iliac muscles. Chemotherapy and targeted therapy were administered, and the patient currently survives with the presence of tumors. Small round cell undifferentiated sarcoma is an uncommon and highly invasive tumor, and clinical surgeons need to raise their awareness and realize to the maximum extent possible that this disease can be described through a multi-modal combination of immunohistochemistry and genetic test to improve diagnostic accuracy and reduce missed diagnoses. Further research in the field of biology is necessary to explore targeted drugs specifically suitable for this disease.

Prevalence and clinical implications of germline pathogenic variants in cancer predisposing genes in young patients across sarcoma subtypes

BACKGROUND

Sarcomas are a rare and diverse group of cancers occurring mainly in young individuals for which an underlying germline genetic cause remains unclear in most cases.

METHODS

Germline DNA from 177 children, adolescents and young adults with soft tissue or bone sarcomas was tested using multigene panels with 113 or 126 cancer predisposing genes (CPGs) to describe the prevalence of germline pathogenic/likely pathogenic variants (GPVs). Subsequent testing of a subset of tumours for loss of heterozygosity (LOH) evaluation was performed to investigate the clinical and molecular significance of these variants.

RESULTS

GPVs were detected in 21.5% (38/177) of the patients (15.8% in children and 21.6% in adolescents and young adults), with dominant CPGs being altered in 15.2% overall. These variants were found in genes previously associated with the risk of developing sarcomas (TP53, RB1, NF1, EXT1/2) but also in genes where that risk is still emerging/limited (ERCC2, TSC2 and BRCA2) or unknown (PALB2, RAD50, FANCM and others). The detection rates of GPVs varied from 0% to 33% across sarcoma subtypes and GPV carriers were more likely to present more than one primary tumour than non-carriers (21.1%×6.5%; p=0.012). Loss of the wild-type allele was detected in 48% of tumours from GPV carriers, mostly in genes definitively associated with sarcoma risk.

CONCLUSION

Our findings reveal that a high proportion of young patients with sarcomas presented a GPV in a CPG, underscoring the urgency of establishing appropriate genetic screening strategies for these individuals and their families.

Benefit of Using Both Ultrasound Imaging and Clinical Information for Predicting Malignant Soft Tissue Tumors

OBJECTIVE

Ultrasonography (US) is the primary imaging method for soft tissue tumors (STTs), the diagnostic performance of which still requires improvement. To achieve an accurate evaluation of STTs, we built the diagnostic nomogram for STTs using the clinical and US features of patients with STTs.

METHODS

A total of 613 patients with 195 malignant and 418 benign STTs were retrospectively recruited. We used a blend of clinical and ultrasonic features, as well as exclusively US features, to develop two distinct diagnostic models for STTs: the clinical-US model and the US-only model, respectively. The two models were evaluated and compared by measuring their areas under the receiver operating characteristic curve (AUC), calibration, integrated discrimination improvement (IDI) and decision curve analysis. The performance of the clinical-US model was also compared with that of two radiologists.

RESULTS

The clinical-US model had better diagnostic performance than the model based on US imaging features alone (AUCs of the clinical-US and US-only models: 0.95 [0.93-0.97] vs. 0.89 [0.87-0.92], p < 0.001; IDI of the two models: 0.15 ± 0.03, p < 0.001). The clinical-US model was also superior to the two radiologists in diagnosing STTs (AUCs of clinical-US model and two radiologists: 0.95 [0.93-0.97] vs. 0.79 [0.75-0.82] and 0.83 [0.80-0.85], p < 0.001).

CONCLUSION

The diagnostic model based on clinical and US imaging features had high diagnostic performance in STTs, which could help identify malignant STTs for radiologists.

Transformation of a long-standing phosphaturic tumor-inducing osteomalacia into malignancy

Key Clinical Message

Tumor-induced osteomalacia is a paraneoplastic syndrome characterized by renal phosphate wasting and deranged bone turnover. Clinicians should consider tumor-induced osteomalacia in unexplained hypophosphatemia and investigate for underlying tumors.

Abstract

Tumor-induced osteomalacia (TIO) is a rare paraneoplastic syndrome characterized by renal phosphate wasting, which leads to deranged bone turnover. TIO is usually associated with benign mesenchymal tumors, although it has also been reported in malignant tumors. We present the case of a 56-year-old individual who experienced a protracted 6-year clinical course characterized by hypophosphatemia, weakness, and kyphosis, alongside the presence of a foot tumor. Subsequently, this lesion displayed malignant behavior and was ultimately diagnosed as a high-grade sarcoma. To date, this case is among the 10 reported cases in the literature of a mesenchymal tumor associated with TIO undergoing malignant transformation. This report underscores the importance of a comprehensive evaluation of patients with unexplained hypophosphatemia and highlights the need for diligent follow-up to detect possible malignant transformation of the underlying tumor. Clinicians should consider TIO in the differential diagnosis of hypophosphatemia and promptly investigate for the presence of an underlying tumor, as early detection may improve the patient's prognosis.

Undifferentiated Pleomorphic Sarcoma of a Chronic Burn Scar of the Knee With Lymph Node Metastasis

Malignant transformation of chronic burn scars are usually toward cutaneous lineages, including squamous cell carcinoma, basal cell carcinoma, and malignant melanoma. Sarcomas are less common. Undifferentiated pleomorphic sarcoma(UPS) is a subtype of soft tissue sarcoma with storiform-pleomorphic cells of uncertain origin, and has sparingly been reported to arise from burn scars. The majority are localized lesions probably due to the spatial distance of mesenchymal cells from the epithelium. The authors describe a rare case of UPS of the chronic burn scar of his knee with ipsilateral femoral and external iliac lymph node metastasis.

Comprehensive analysis reveals potential therapeutic targets and an integrated risk stratification model for solitary fibrous tumors

Solitary fibrous tumors (SFTs) are rare mesenchymal tumors with unpredictable evolution and with a recurrence or metastasis rate of 10-40%. Current medical treatments for relapsed SFTs remain ineffective. Here, we identify potential therapeutic targets and risk factors, including IDH1 p.R132S, high PD-L1 expression, and predominant macrophage infiltration, suggesting the potential benefits of combinational immune therapy and targeted therapy for SFTs. An integrated risk model incorporating mitotic count, density of Ki-67+ cells and CD163+ cells, MTOR mutation is developed, applying a discovery cohort of 101 primary non-CNS patients with negative tumor margins (NTM) and validated in three independent cohorts of 210 SFTs with the same criteria, and in 36 primary CNS SFTs with NTM. Compared with the existing models, our model shows significantly improved efficacy in identifying high-risk primary non-CNS and CNS SFTs with NTM for tumor progression.Our findings hold promise for advancing therapeutic strategies and refining risk prediction in SFTs.

PROTAC-Based Protein Degradation as a Promising Strategy for Targeted Therapy in Sarcomas

Sarcomas are heterogeneous bone and soft tissue cancers representing the second most common tumor type in children and adolescents. Histology and genetic profiling discovered more than 100 subtypes, which are characterized by peculiar molecular vulnerabilities. However, limited therapeutic options exist beyond standard therapy and clinical benefits from targeted therapies were observed only in a minority of patients with sarcomas. The rarity of these tumors, paucity of actionable mutations, and limitations in the chemical composition of current targeted therapies hindered the use of these approaches in sarcomas. Targeted protein degradation (TPD) is an innovative pharmacological modality to directly alter protein abundance with promising clinical potential in cancer, even for undruggable proteins. TPD is based on the use of small molecules called degraders or proteolysis-targeting chimeras (PROTACs), which trigger ubiquitin-dependent degradation of protein of interest. In this review, we will discuss major features of PROTAC and PROTAC-derived genetic systems for target validation and cancer treatment and focus on the potential of these approaches to overcome major issues connected to targeted therapies in sarcomas, including drug resistance, target specificity, and undruggable targets. A deeper understanding of these strategies might provide new fuel to drive molecular and personalized medicine to sarcomas.

Novel PD-L1- and collagen-expressing patient-derived cell line of undifferentiated pleomorphic sarcoma (JBT19) as a model for cancer immunotherapy

Soft tissue sarcomas are aggressive mesenchymal-origin malignancies. Undifferentiated pleomorphic sarcoma (UPS) belongs to the aggressive, high-grade, and least characterized sarcoma subtype, affecting multiple tissues and metastasizing to many organs. The treatment of localized UPS includes surgery in combination with radiation therapy. Metastatic forms are treated with chemotherapy. Immunotherapy is a promising treatment modality for many cancers. However, the development of immunotherapy for UPS is limited due to its heterogeneity, antigenic landscape variation, lower infiltration with immune cells, and a limited number of established patient-derived UPS cell lines for preclinical research. In this study, we established and characterized a novel patient-derived UPS cell line, JBT19. The JBT19 cells express PD-L1 and collagen, a ligand of the immune checkpoint molecule LAIR-1. JBT19 cells can form spheroids in vitro and solid tumors in immunodeficient nude mice. We found JBT19 cells induce expansion of JBT19-reactive autologous and allogeneic NK, T, and NKT-like cells, and the reactivity of the expanded cells was associated with cytotoxic impact on JBT19 cells. The PD-1 and LAIR-1 ligand-expressing JBT19 cells show ex vivo immunogenicity and effective in vivo xenoengraftment properties that can offer a unique resource in the preclinical research developing novel immunotherapeutic interventions in the treatment of UPS.

Denosumab for giant cell tumors of bone from 2010 to 2022: a bibliometric analysis

Giant cell tumors of the bone (GCTB) are considered moderately malignant bone tumors. Denosumab, as a neoadjuvant therapy, provides new possibilities for treating GCTB. However, even after multiple studies and long-term clinical trials, there are limitations in the treatment process. Research data and Medical Subject Headings terms related to denosumab and GCTB were collected from January 2010 to October 2022 using the Web of Science and MeSH ( https://meshb.nlm.nih.gov ) browsers. These data were imported into CiteSpace and VOSviewer softwares for bibliometric analysis. Overall, 445 publications on denosumab and GCTB were identified. Over the last 12 years, the growth rate of the total number of publications has remained relatively stable. The USA published the highest number of articles (83) and had the highest centrality (0.42). Amgen Inc. and Istituto di Ricovero e Cura a Carattere Scientifico (IRCCS) First Ortoped Rizzoli were identified as the most influential institutions. Many authors have made outstanding contributions to this field. Lancet Oncology had the highest journal impact factor (54.433). Local recurrence and drug dosage are current research hotspots, and future development trends will mainly focus on prognostic markers of GCTB and the development of new therapies. Further research is required to analyze denosumab's safety and efficacy and understand its local recurrence of GCTB, to identify the optimal dose. Future progress in this field will likely focus on exploring new diagnostic and recurrence markers to monitor disease progression and examine new therapeutic targets and treatment strategies.

Enhancing Healthcare for Sarcoma Patients: Lessons from a Diagnostic Pathway Efficiency Analysis

Sarcomas, rare and with lower survival rates than common tumors, offer insights into healthcare efficiency via the analysis of the total interval of the diagnostic pathway, combining the patient interval (time between the first symptom and visit with a physician) and diagnostic interval (time between first physician visit and histological diagnosis). Switzerland's healthcare system, Europe's costliest, lacks research on treating rare conditions, like mesenchymal tumors. This study examines the total interval of the diagnostic pathway for optimization strategies. Analyzing a dataset of 1028 patients presented from 2018 to 2021 to the Swiss Sarcoma Board (MDT/SB-SSN), this retrospective analysis delves into bone sarcoma (BS), soft-tissue sarcoma (STS), and their benign counterparts. Demographic and treatment data were extracted from medical records. The patient interval accounted for the largest proportion of the total interval and secondary care interval for the largest proportion of the diagnostic interval. Age, grade, and localization could be elicited as influencing factors of the length of different components of the total interval. An increasing age and tumor size, as well as the axial localization, could be elicited as factors increasing the probability of sarcoma. The patient and secondary care interval (SCI) offer the greatest potential for optimization, with SCI being the bottleneck of the diagnostic interval. New organizational structures for care work-ups are needed, such as integrated practice units (IPU) as integral part of value-based healthcare (VBHC).

Synovial Sarcoma in the Extremity: Diversity of Imaging Features for Diagnosis and Prognosis

Synovial sarcomas are rare and highly aggressive soft-tissue sarcomas, primarily affecting adolescents and young adults aged 15-40 years. These tumors typically arise in the deep soft tissues, often near the large joints of the extremities. While the radiological features of these tumors are not definitely indicative, the presence of calcification in a soft-tissue mass (occurring in 30% of cases), adjacent to a joint, strongly suggests the diagnosis. Cross-sectional imaging characteristics play a crucial role in diagnosing synovial sarcomas. They often reveal significant characteristics such as multilobulation and pronounced heterogeneity (forming the "triple sign"), in addition to features like hemorrhage and fluid-fluid levels with septa (resulting in the "bowl of grapes" appearance). Nevertheless, the existence of non-aggressive features, such as gradual growth (with an average time to diagnosis of 2-4 years) and small size (initially measuring < 5 cm) with well-defined margins, can lead to an initial misclassification as a benign lesion. Larger size, older age, and higher tumor grade have been established as adverse predictive indicators for both local disease recurrence and the occurrence of metastasis. Recently, the prognostic importance of CT and MRI characteristics for synovial sarcomas was elucidated. These include factors like the absence of calcification, the presence of cystic components, hemorrhage, the bowl of grape sign, the triple sign, and intercompartmental extension. Wide surgical excision remains the established approach for definitive treatment. Gaining insight into and identifying the diverse range of presentations of synovial sarcomas, which correlate with the prognosis, might be helpful in achieving the optimal patient management.

Intracranial Relapse in Pediatric Sarcoma

Advances in local control techniques, chemotherapy regimens, and imaging modalities have led to improvements in both morbidity and mortality in pediatric sarcoma patients. However, approximately one-third of patients develop disease relapse and intracranial metastasis was considered rare. The incidence of sarcoma brain metastasis is thought to have increased and is associated with grim outcomes. This was a retrospective study of 3 deidentified patient charts illustrating the possibility of the central nervous system as a potential site for pediatric sarcoma relapse and investigate the patterns of such relapses. We note this is the first report of infantile fibrosarcoma brain metastasis and a rare report of sarcoma lymph node metastasis. In addition, each patient was treated with targeted therapies, including entrectinib, Ruxolitnib, and pazopanib. Caregivers in cases 2 and 3 reported new-onset neurological manifestations before identification of new brain metastasis, indicating a lag in detection of new intracranial relapse in asymptomatic sarcoma patients. We suggest implementing a brief review of systems screening tool focused on concerning neurological manifestations to screen for new brain metastasis.

Isolated lesions of the pubis

The osseous pelvis is a well-known area of various primary and secondary bone tumours, tumour mimics, and infections. Isolated lesions of the pubis (ILP) are rare, with few case reports in the literature. Given their sparsity, such lesions may pose a great diagnostic challenge due to varied clinical presentations and imaging features. In this study, we report the largest case series of ILP. We discuss the patient demographics, differentials, surgical approaches, and management.

Functional Profiling of Soft Tissue Sarcoma Using Mechanistic Models

Soft tissue sarcoma is an umbrella term for a group of rare cancers that are difficult to treat. In addition to surgery, neoadjuvant chemotherapy has shown the potential to downstage tumors and prevent micrometastases. However, finding effective therapeutic targets remains a research challenge. Here, a previously developed computational approach called mechanistic models of signaling pathways has been employed to unravel the impact of observed changes at the gene expression level on the ultimate functional behavior of cells. In the context of such a mechanistic model, RNA-Seq counts sourced from the Recount3 resource, from The Cancer Genome Atlas (TCGA) Sarcoma project, and non-diseased sarcomagenic tissues from the Genotype-Tissue Expression (GTEx) project were utilized to investigate signal transduction activity through signaling pathways. This approach provides a precise view of the relationship between sarcoma patient survival and the signaling landscape in tumors and their environment. Despite the distinct regulatory alterations observed in each sarcoma subtype, this study identified 13 signaling circuits, or elementary sub-pathways triggering specific cell functions, present across all subtypes, belonging to eight signaling pathways, which served as predictors for patient survival. Additionally, nine signaling circuits from five signaling pathways that highlighted the modifications tumor samples underwent in comparison to normal tissues were found. These results describe the protective role of the immune system, suggesting an anti-tumorigenic effect in the tumor microenvironment, in the process of tumor cell detachment and migration, or the dysregulation of ion homeostasis. Also, the analysis of signaling circuit intermediary proteins suggests multiple strategies for therapy.

The Potential for Targeting AVIL and Other Actin-Binding Proteins in Rhabdomyosarcoma

Rhabdomyosarcoma (RMS) is the most common pediatric soft-tissue cancer with a survival rate below 27% for high-risk children despite aggressive multi-modal therapeutic interventions. After decades of research, no targeted therapies are currently available. Therapeutically targeting actin-binding proteins, although promising, has historically been challenging. Recent advances have made this possibility more salient, including our lab's identification of advillin (AVIL), a novel oncogenic actin-binding protein that plays a role in many cytoskeletal functions. AVIL is overexpressed in many RMS cell lines, patient-derived xenograft models, and a cohort of 30 clinical samples of both the alveolar (ARMS) and embryonal (ERMS) subtypes. Overexpression of AVIL in mesenchymal stem cells induces neoplastic transformation both in vitro and in vivo, and reversing overexpression through genetic modulation reverses the transformation. This suggests a critical role of AVIL in RMS tumorigenesis and maintenance. As an actin-binding protein, AVIL would not traditionally be considered a druggable target. This perspective will address the feasibility of targeting differentially expressed actin-binding proteins such as AVIL therapeutically, and how critical cell infrastructure can be damaged in a cancer-specific manner.

Giant liposarcoma of esophagus: a rare case report

BACKGROUND

Liposarcoma is a malignant mesenchymal tumor that most commonly involves the retroperitoneum and lower extremities. However, liposarcoma of esophagus has been rarely reported in the literature.

CASE PRESENTATION

We report a case of a 46-year-old man with complaint of intermittent dysphagia for 6 years, accompanied with paroxysmal vomiting of pedicled tumor to the mouth. Imaging studies showed a huge mixed density lesion in the middle esophageal lumen. Surgical resection of the tumor was performed through an external cervical approach. Microscopically, the tumor was composed of mature adipocytes in normal adipose tissue prominently intersected by sparsely cellular fibrous septa containing atypical, enlarged spindle cells with hyperchromatic nuclei. Immunohistochemically, the tumor cells were positive for Vimentin, S-100, CD34 and MDM2. Besides, fluorescence in situ hybridization (FISH) analysis indicated the presence of amplification involving MDM2 gene. The patient was diagnosed as having esophageal well-differentiated liposarcoma and recovered well after the operation.

CONCLUSIONS

Esophageal liposarcoma is an extremely rare tumor. Due to the nonspecific clinical manifestation and lack of experience, it is challenging to make a clear diagnosis before operation. Definite diagnosis of esophageal liposarcoma depends on histopathology, immunohistochemistry and molecular analysis.

Expanding the Clinical Utility of Targeted RNA Sequencing Panels beyond Gene Fusions to Complex, Intragenic Structural Rearrangements

Gene fusions are a form of structural rearrangement well established as driver events in pediatric and adult cancers. The identification of such events holds clinical significance in the refinement, prognostication, and provision of treatment in cancer. Structural rearrangements also extend beyond fusions to include intragenic rearrangements, such as internal tandem duplications (ITDs) or exon-level deletions. These intragenic events have been increasingly implicated as cancer-promoting events. However, the detection of intragenic rearrangements may be challenging to resolve bioinformatically with short-read sequencing technologies and therefore may not be routinely assessed in panel-based testing. Within an academic clinical laboratory, over three years, a total of 608 disease-involved samples (522 hematologic malignancy, 86 solid tumors) underwent clinical testing using Anchored Multiplex PCR (AMP)-based RNA sequencing. Hematologic malignancies were evaluated using a custom Pan-Heme 154 gene panel, while solid tumors were assessed using a custom Pan-Solid 115 gene panel. Gene fusions, ITDs, and intragenic deletions were assessed for diagnostic, prognostic, or therapeutic significance. When considering gene fusions alone, we report an overall diagnostic yield of 36% (37% hematologic malignancy, 41% solid tumors). When including intragenic structural rearrangements, the overall diagnostic yield increased to 48% (48% hematologic malignancy, 45% solid tumor). We demonstrate the clinical utility of reporting structural rearrangements, including gene fusions and intragenic structural rearrangements, using an AMP-based RNA sequencing panel.

Survival of a patient with five recurrences of retroperitoneal liposarcoma over a period of 13 years: A case report and review

Retroperitoneal liposarcoma (RPLS) is a rare tumor that occurs in the retroperitoneal region and accounts for ~0.2% of all malignant tumor incidence. The present study describes the treatment of a surviving patient with RPLS that recurred five times in 13 years. This case has a long survival time and numerous relapses, which is a rare occurrence. The 40-year-old female patient was admitted to Shaoxing Second Hospital (Shaoxing, China) with an abdominal mass. Abdominal computed tomography (CT) scan revealed multiple liposarcoma recurrences in the abdominal, pelvic and retroperitoneal areas. As the diagnosis of RPLS was the fifth recurrence, cytoreductive surgery was performed and post-operative pathology suggested mixed liposarcoma. The patient underwent six cycles of doxorubicin and ifosfamide regimen chemotherapy and targeted therapy with anlotinib following surgery; no evidence of disease progression was found on abdominal CT scan during follow-up. The present study also reviewed the literature in terms of the clinical diagnosis, treatment, pathological characteristics and similar cases of liposarcoma with the aim of improving diagnosis and treatment.

Differential impacts of initial treatment status on long-term survival in patients with sarcomas treated in a referral center according to histologic type and anatomic site

OBJECTIVE

The aim of this work was to estimate the magnitude of the differential impacts of initial treatment status relative to the impact of classic clinicopathologic factors on the long-term overall survival (OS) of sarcoma patients in a referral cancer center.

METHODS

From the institutional database, we identified 2185 patients who presented to the institutional multidisciplinary team (MDT) prior to (N = 717, 32.8%) or after (N = 1468, 67.2%) initial treatment, with a first diagnosis of sarcoma from January 1999 to December 2018. Descriptive, univariate and multivariate analyses were applied to identify the factors related to OS. By performing propensity score matching of each completely MDT-treated patient to a referral patient with similar characteristics, the differential impacts of the identified risk and prognostic factors on OS in the 2 groups were estimated by the Kaplan‒Meier survival curves, log-rank test and Cox proportional hazard regression; the results were compared using calibrated nomograph models and forest plots.

RESULTS

Adjusted for the clinicopathologic factors of patient age, sex, primary site, tumor grade, tumor size, resection margin and histology, hazard ratio-based modeling analysis indicated that the initial treatment status was an independent but intermediate prognostic factor associated with long-term OS. The major impacts of the initial and comprehensive MDT-based management on significant improvement of the 20-year OS of sarcomas were reflected in the subgroup of patients with stromal, undifferentiated pleomorphic, fibromatous, fibroepithelial, or synovial neoplasms and tumors in the breast, gastrointestinal tract, or soft tissues of limb and trunk.

CONCLUSIONS

This retrospective study supports early referral of patients with soft tissue masses of unknown identity to a specialized MDT before biopsy and initial resection to reduce the risk of death but highlights an unmet need for a greater understanding of some of the most difficult sarcoma subtypes and subsites and their management.

Beneath the Layers: Deciphering the Molecular Pathways, Therapeutic Avenues, and Neurological Connections of Soft Tissue Sarcomas

Soft tissue sarcomas (STSs) are a heterogeneous group of malignancies that have long posed challenges in terms of diagnosis, treatment, and management. This narrative review provides a comprehensive exploration into the multifaceted realm of STS, spanning from its historical origins to the latest advancements in research and clinical care. We delve into the molecular intricacies of STS, highlighting the genetic and epigenetic aberrations that drive these tumors. The review emphasizes the neurological implications of STS, a relatively underexplored area, shedding light on the interplay between tumor biology and neural processes. The evolving therapeutic landscape is discussed, with a focus on the promise of targeted therapies, immunotherapy, and precision medicine. A significant portion is dedicated to the patient-centric approach, underscoring the importance of holistic care that addresses both the physical and psychological needs of STS patients. Furthermore, we highlight the gaps in current research and clinical practices, offering insights into potential avenues for future exploration. This review serves as a valuable resource for clinicians, researchers, and the broader scientific community, encapsulating the current state of STS knowledge and pointing toward future directions in this dynamic field.

Unexpected Durable Complete Response With Anti-PD-L1 Blockade in Metastatic Undifferentiated Pleomorphic Sarcoma: A Case Report With Host and Tumor Biomarker Analysis

We extensively characterized a metastatic UPS with a 71-month lasting complete response to immunotherapy.

Novel-fosfamide monotherapy or in combination with doxorubicin versus doxorubicin alone in patients with advanced soft tissue sarcoma: A pooled analysis of randomized clinical trials

BACKGROUND

Novel-fosfamides (NFOs) belong to active metabolites of ifosfamide that bypass the generation of toxic byproducts. In this analysis, we aimed to comprehensively assess the benefits and risks of NFO monotherapy or in combination with doxorubicin (DOX) versus single-drug DOX in previously untreated patients with advanced soft-tissue sarcoma (ASTS).

METHODS

Online PubMed, Web of Science, Embase, and Cochrane CENTRAL databases were systematically searched on April 26, 2022. Objective response rate and disease control rate were primary outcomes. Overall survival (OS), progression-free survival (PFS), and grade ≥ 3 treatment-related adverse events were secondary outcomes.

RESULTS

In all, 3 randomized clinical trials with a total of 1207 ASTS patients were eligible. DOX plus NFO combination therapy showed higher risk ratios of objective response rate (1.50, 95% CI 1.20-1.68, P = .0003) and disease control rate (1.15, 95% CI 1.05-1.27, P = .0030) compared with DOX monotherapy. Nevertheless, NFO-based monotherapy and combination therapy were found no improvements on OS (hazard ratio 0.93, 95% CI 0.52-1.65, P = .8050) and PFS (hazard ratio 0.88, 95% CI 0.54-1.43, P = .6088) against DOX. More incidences of grade 3 or worse anemia, thrombocytopenia, stomatitis, diarrhea, constipation, and febrile neutropenia were observed in NFO-based treatments.

CONCLUSION

Adding NFO to DOX as first-line therapy improved the responses in ASTS patients but did not prolong OS and PFS. Grade 3 or worse treatment-related adverse events should be treated with caution during the NFO-based therapies.

Bilateral Renal Auto-Transplantation for Retroperitoneal Sarcomas: Is It Underutilized?

Sarcomas are a rare tumor of mesenchymal origin. The liposarcoma is the most common sarcoma of the retroperitoneum. Liposarcomas are typically low grade, and present at an advanced stage and a large size. We report a case of a large retroperitoneal liposarcoma, approximately 50 kg, encasing both kidneys, which was managed via a two-stage resection and staged renal auto-transplantation into the intra-peritoneal pelvis. The patient maintained normal renal function throughout, and remains disease free two years post-resection. Renal auto-transplantation with pelvic placement may facilitate improved margin-free resection. Renal relocation may allow the use of curative-intent ablative therapies such as radiofrequency ablation and radiation in cases of retroperitoneal recurrence.

Indicators of clinical performance in monitoring soft tissue sarcoma management: a population-based perspective

Background

Soft tissue sarcomas (STS) are rare malignancies which prognosis varies significantly by primary site, histological subtype, and tumor stage. Their low incidence, and the complexity of their clinico-pathological characteristics demand standardized, cancer-tailored diagnostics and therapies managed at high-volume, multidisciplinary care centers. This study evaluates the quality of STS management in north-east Italy (Veneto Region) through a list of ad hoc defined clinical indicators.

Methods

This population-based study concerns all incident cases of STS in 2018 (214 cases) recorded in the adult population censored by the Veneto's regional Cancer Registry. Based on the international literature, a multidisciplinary working group of experts identified a set of indicators for monitoring the quality of diagnostic, therapeutic, and end-of-life clinical interventions. The quality of care was assessed by comparing the reference thresholds with the indicators' values achieved in clinical practice.

Results

Diagnostic procedures showed poor adherence to the thresholds, with a low percentage of histological diagnoses validated by a second opinion. The indicators relating to the surgical treatment of superficial, small, low-grade STS, or of medium, high-grade STS of the head-neck, trunk, or limbs were consistent with the thresholds, while for intermediate, high-grade (large-sized, deep) and retroperitoneal STS they fell significantly below the thresholds.

Conclusion

A critical evaluation of the clinical indicators allowed to uncover the procedures needing corrective action. Monitoring clinical care indicators improves cancer care, confirms the importance of managing rare cancers at highly specialized, high-volume centers, and promotes the ethical sustainability of the healthcare system.

Primary pleomorphic liposarcoma of bone: A case report with literature review

INTRODUCTION AND IMPORTANCE

Primary pleomorphic liposarcoma of bone is an exceedingly rare sarcoma.

CASE PRESENTATION

We herein report the case of a primary pleomorphic liposarcoma of the distal femur in a 20-year-old female patient. Magnetic resonance imaging showed a 25.4-mm medullary necrotic tumor process in the lower third of the distal right femoral meta-diaphysis that was weakly enhanced after gadolinium injection. The patient first underwent an open biopsy. Microscopically, a pleomorphic liposarcoma were suspected. Immunohistochemically, tumor cells expressed the S-100 protein. Fluorescent in situ hybridization showed the absence of MDM2 gene amplification and the absence of EWING/PNET translocation. The diagnosis of primary pleomorphic liposarcoma of the bone was then retained. A wide resection and chemotherapy were performed. The patient died of liver metastasis after 8 months of follow-up.

CLINICAL DISCUSSION AND CONCLUSION

Primary pleomorphic liposarcoma has no specific clinical or radiological findings. Histological diagnosis and molecular study are crucial tools for making an accurate diagnosis.

The magnetic resonance characteristics of sinonasal rhabdomyosarcoma in adults: analysis of 27 cases and comparison with pathological subtypes

BACKGROUND

Sinonasal rhabdomyosarcoma (RMS) in adults is extremely rare, and early diagnosis and treatment are crucial to improve the patient's prognosis. The purpose of this study was to evaluate the magnetic resonance imaging (MRI) findings of sinonasal RMS in adults and analyze the correlations between the imaging features and pathological subtypes.

METHODS

We reviewed 27 patients with pathologically proven RMS of the nasal cavity and paranasal sinuses, including embryonal RMS (ERMS) in 14 patients, alveolar RMS (ARMS) in seven patients, and mixed-type RMS in six patients. Conventional MRI was performed in all 27 patients, and high-resolution diffusion-weighted imaging was conducted in 25 patients. The tumor location, size, morphological features, signal intensity, texture, contrast enhancement characteristics, lymph node metastases, apparent diffusion coefficients (ADCs), and involvement of local soft tissues were independently assessed by two authors.

RESULTS

On MR imaging, sinonasal RMS appeared isointense on T1-weighted imaging in 21 cases (77.8%) and heterogeneously hyperintense on T2-weighted imaging in 18 patients (66.7%). After enhancement, the tumors were heterogeneously enhanced in 24 cases (88.9%). Botryoid enhancement with multiple small rings resembling bunches of grapes was found in 15 cases (55.6%). Mucosal invasion of the maxillary sinus was identified in 51.9% patients. Skull and orbit involvement were found in 55.6% and 81.5% patients, respectively. Lymph node metastasis was seen in 18 cases (66.7%). There were significant differences in botryoid enhancement (P = 0.044) and skull involvement (P = 0.044) among different histological subtypes. The mean ADC value of RMS was 0.73 ± 0.082 × 10^-3 mm²/s, and there was no significant difference among different histological subtypes.

CONCLUSIONS

Some characteristic MRI findings such as botryoid enhancement in the ethmoid sinus, involvement of the orbit and skull, and a lower ADC value can provide important clues for preoperative diagnosis of sinonasal RMS in adults. Further, botryoid enhancement was more common in ERMS, while skull involvement was more common in ARMS.

Whole genome sequencing for metastatic mutational burden in extraskeletal myxoid chondrosarcoma

Extraskeletal myxoid chondrosarcoma (EMC) is an ultra-rare cancer that makes up less than 3% of all soft tissue sarcomas. It most often arises in the soft tissues of the proximal limbs and has a higher incidence in males. Though EMC has a good prognosis, it has an indolent course with high rates of local recurrence as well as metastasis to the lungs. EMC is characterized in 70% of cases by an EWS1-NR4A3 translocation, leading to constitutive expression of NR4A3. Structural variants (SVs) in EMC, especially large-scale genomic alterations, have not been well studied and studies are severely limited by sample size. In this study, we describe Whole Genome Sequencing (WGS) of a rare case of matched EMC primary tumor, lung metastasis, and pelvic metastasis to identify genomic alterations. We examined somatic variants, copy number variants (CNVs), and larger scale SVs such as translocations and breakend points. While the primary tumor and lung metastasis had similar somatic variations and CNVs, the pelvic metastasis had more unique SVs with especially increased mutational burden of SVs in chromosome 2. This suggests that different molecular drivers appear in more advanced, relapsing EMC compared with the primary tumor and early lung metastasis. Genomic studies such as ours may identify novel molecular complexities in rare cancers that may be leveraged for therapeutic strategies and precision medicine.

Identification and validation of a nomogram predicting cancer-specific survival for elderly patients with adult fibrosarcoma: a multicenter retrospective study

Background

Due to the low incidence of adult fibrosarcoma (AFS), it is difficult for clinicians to assess cancer-specific survival (CSS) in elderly patients based on this study. The study aimed to develop nomograms capable of accurately predicting 3-, 5-, and 8-year CSS in patients over 40 years of age with AFS.

Methods

Data were collected from The Surveillance, Epidemiology, and End Results (SEER) registry. 586 patients were included in this study. Univariate as well as multivariate Cox regression analyses were applied to identify independent risk factors. A nomogram was constructed and validated to predict the 3-, 5-, and 8-year CSS of patients.

Results

Five variables including age, sex, stage, grade, and chemotherapy status were considered independent risk factors and were used to construct the nomogram. The nomogram was well validated. The C-indexes of the training cohort and the validation cohort are 0.766 and 0.780, respectively. In addition, the area under the curves for 3-, 5- and 8-year CSS are 0.824, 0.846 and 0.840 in the training cohort, 0.835, 0.806 and 0.829 in the validation cohort. Calibration curves were also plotted to show that predicted endings have a well fit for the true endings. Finally, decision curve analysis demonstrates that the nomogram can bring a high benefit to patients.

Conclusion

We successfully constructed a highly accurate nomogram to predict the CSS of AFS patients at 3-, 5-, and 8 years. The nomogram can greatly help clinicians and patients with AFS.

Garcinol and Anacardic Acid, Natural Inhibitors of Histone Acetyltransferases, Inhibit Rhabdomyosarcoma Growth and Proliferation

Rhabdomyosarcoma (RMS) is a malignant tumour of the soft tissues. There are two main histopathological types: alveolar and embryonal. RMS occurs mainly in childhood and is a result of the deregulation of growth and differentiation of muscle cell precursors. There is an increasing amount of data indicating that numerous epigenetic alterations within chromatin and histone proteins are involved in the pathogenesis of this malignancy. Histone acetylation is one of the most important epigenetic modifications that is catalysed by enzymes from the group of histone acetyltransferases (HAT). In this study, the impact of the natural histone acetyltransferase inhibitors (HATi)-garcinol (GAR) and anacardic acid (AA)-on the biology of RMS cells was evaluated through a series of in vitro tests measuring proliferation, viability, clonogenicity, cell cycle and apoptosis. Moreover, using oligonucleotide microarrays and real-time PCR, we identified several genes whose expression changed after GAR and AA treatment. The examined HATi significantly reduce the invasive phenotype of RMS cells by inhibiting the growth rate, viability and clonogenic abilities. What is more, these substances cause cell cycle arrest in the G2/M phase, induce apoptosis and affect the genetic expression of the endoplasmic reticulum stress sensors. GAR and AA may serve as promising potential anti-cancer drugs since they sensitize the RMS cells to chemotherapeutic treatment.

Solitary fibrous tumor with IGF-II-induced non-islet cell tumor hypoglycemia: a case report and molecular characterization by next-generation sequencing

Background

Non-islet cell tumor-induced hypoglycemia (NICTH) is a rare, life-threatening medical condition caused by excessive insulin-like growth factor II (IGF-II) secretion from tumors of most commonly mesenchymal origin. Using next-generation sequencing, we have characterized the genome and transcriptome of the resected IGF-II-secreting solitary fibrous tumor from a patient with severe hypoglycemia accompanied by hypoglycemia unawareness.

Case presentation

A 69-year-old male patient presenting with abdominal discomfort was examined using computer tomography, revealing a large lesion at the lesser pelvis extending above the umbilicus. As no bone and lymph node metastases were detected, the patient was scheduled for laparotomy. Before surgery, the patient presented with symptoms of severe hypoglycemia. Suppressed C-peptide levels and subsequent hypokalemia indicated a possible case of NICTH. The patient was treated with methylprednisolone (8 mg) to assess hypoglycemia. After the surgery, mild hypoglycemia was present for the postoperative period, and no radiological recurrences were observed 3 and 12 months after discharge. Histopathological examination results were consistent with the diagnosis of malignant solitary fibrous tumor (SFT). Overexpression of IGF-II was confirmed by both immunohistochemistry and RNA sequencing. Further NGS analysis revealed an SFT characteristic alteration-NAB2-STAT6 fusion. Additionally, three deleterious missense variants were detected in oncogenes BIRC6, KIT, and POLQ, and one homozygous in-frame deletion in the RBM10 tumor suppressor gene.

Conclusion

While the NAB2-STAT6 fusions are well characterized, the mutational landscape of SFTs remains understudied. This study reports the importance of NGS to characterize SFTs as we detected four coding variants in genes (BIRC6, KIT, POLQ, and RBM10) associated with tumorigenesis that could potentially contribute to the overall pathogenesis of SFT.

Sclerosing Epithelioid Fibrosarcoma of the Spine: Diagnosis and Treatment of a Rare Entity

Sclerosing epithelioid fibrosarcoma (SEF) is a rare subtype of sarcoma with high rates of local recurrence and distant metastasis. Morphologically, it resembles other mesenchymal and non-mesenchymal tumors, making it a diagnostic challenge. Treatment relies mostly on surgery with adjuvant chemotherapy or radiotherapy (RT). A 46-year-old woman who presented with lumbar pain and weight loss underwent a computed tomography (CT) scan, magnetic resonance imaging (MRI), and a [18F]-fluorodeoxyglucose positron emission tomography-computed tomography (18F-FDG PET/CT) scan, which showed a lesion involving the L5 vertebra. An incisional biopsy of the lesion established the diagnosis of SEF, with diffuse expression of MUC4 and focal expression of EMA. The patient was treated with neoadjuvant RT followed by surgery. Histology was congruent with the previous diagnosis and demonstrated post-radiation changes. In conclusion, SEF is an aggressive type of sarcoma that is easily misdiagnosed, so it is important to consider it in the differential diagnosis to avoid unbeneficial treatments and a detriment to patient survival.

Malignant Melanotic Nerve Sheath Tumors: A Review of Clinicopathologic and Molecular Characteristics

Malignant melanotic nerve sheath tumor (MMNST) which was formerly known as melanocytic schwannoma, is an uncommon aggressive type of nerve sheath tumor. It originates from nerve roots with clonal Schwann cell proliferation and melanin pigment production. MMNST which was once thought to be a benign tumor is now considered a malignant disease based on the latest 2020 World Health Organization classification of soft tissue tumors. Interestingly, despite the histologic features appearing benign with a low proliferation index, the clinical course of this tumor is malignant, which was demonstrated in case series with high rate of recurrences and metastasis. This tumor can occur sporadically or in patients with an underlying familial predisposition syndrome called, Carney's complex. Affected patients will often harbor a germline mutation in the PRKAR1A gene. MMNST can be histologically difficult to distinguish from malignant melanoma, other melanocytic tumors, and Schwannoma. Having a better understanding of its clinic pathologic characteristics and associated conditions is essential in properly diagnosing and managing affected individuals. This includes the possible need for genetic testing to detect germline mutations, genetic counseling, and surveillance according to published recommendations. In this article, we summarize the clinic pathologic and molecular features of MMNST and discuss what is known about its molecular biology and its associations with predisposing conditions. The review was conducted through an extensive PubMed search using keywords then relevant publications were selected.

18F-Fluorodeoxyglucose Positron Emission Tomography/Computed Tomography in a Rare Case of Epithelioid Hemangioendothelioma - A Diagnostic Challenge

Our case highlights the 18F-fluorodeoxyglucose positron emission tomography/computed tomography (18F-FDG PET/CT) scan findings in a rare case of biopsy-proven epithelioid hemangioendothelioma (EHE) in a 66-year-old woman with multi-organ involvement (lung, liver, and bone) who was subsequently treated with palliative radiation therapy and oral pazopanib. Furthermore, follow-up 18F-FDG PET/CT findings are detailed. EHE is a rare malignant vascular neoplasm (<1% of all vascular tumors) with an epithelioid and histiocytoid appearance arising from the vascular endothelial and preendothelial cells.

Infantile fibrosarcoma of the perineum with dorsal metastasis in a neonate: a case report original

BACKGROUND

Infantile fibrosarcoma is a rare pediatric soft tissue tumor and usually appears in children before one year of age. Distal extremities constitute the most frequently affected locations, and other tissues such as the trunk, head and neck, gut, sacrococcygeal region, and viscera are uncommon sites.

CASE PRESENTATION

We describe a rare case of infantile fibrosarcoma arising from the perineum. First, a cystic mass was detected using prenatal ultrasonography, and then an echo was changed in serial ultrasound examinations. A solid cystic lesion was found at term; a hypoechoic lesion occurred in the back. The tumor became so large that massive bleeding occurred, which then underwent surgical resection. Pathological examination confirmed infantile fibrosarcoma.

CONCLUSION

Our report demonstrates not all ultrasonographic findings in cases of infantile fibrosarcoma exhibit a solid mass during the initial examination - an early-stage lesion may reveal a cystic echo. Infantile fibrosarcoma has a good prognosis and surgery constitute the main treatment, with adjuvant chemotherapy being received if necessary.

The Impact of O6-Methylguanine-DNA Methyltransferase (MGMT) Promoter Methylation on the Outcomes of Patients with Leiomyosarcoma Treated with Dacarbazine

Dacarbazine is an important drug in the therapeutic landscape of leiomyosarcoma (LMS). Alkylating agents are subjected to resistance mechanisms based on anti-apoptotic pathways and repair mechanisms, including the DNA repair enzyme O6-methylguanine-DNA methyltransferase (MGMT). In this retrospective study, the methylation status of the MGMT promoter in histological tumor samples from patients with LMS, dacarbazine-based regimens-treated, was measured and correlated with clinical outcomes aimed at optimizing the use of dacarbazine in soft tissue sarcomas. The patients with unmethylated MGMT had better outcomes than those with methylated MGMT. Patients without MGMT methylation had better Progression Free Survival (PFS) when aged ≥62 years compared to those aged <62 years, while PFS of patients with methylated MGMT was less favorable independently of age (p = 0.0054). The patients without a methylated MGMT gene had higher Disease control rate (DCR). These results are not in agreement with the role of the methylated MGMT gene in other tumors, and with this study, we demonstrated the correlation between methylated MGMT and poor prognosis; despite that, sample smallness, heterogeneity of LMS and of treatment history could be selection bias. Predictive markers of response to chemotherapies in sarcomas remain an unmet need.

Integrative profiling analysis reveals prognostic significance, molecular characteristics, and tumor immunity of angiogenesis-related genes in soft tissue sarcoma

Background

Soft tissue sarcoma (STS) is a class of malignant tumors originating from mesenchymal stroma with a poor prognosis. Accumulating evidence has proved that angiogenesis is an essential hallmark of tumors. Nevertheless, there is a paucity of comprehensive research exploring the association of angiogenesis-related genes (ARGs) with STS.

Methods

The ARGs were extracted from previous literature, and the differentially expressed ARGs were screened for subsequent analysis. Next, the least absolute shrinkage and selection operator (LASSO) and Cox regression analyses were conducted to establish the angiogenesis-related signature (ARSig). The predictive performance of the novel ARSig was confirmed using internal and external validation, subgroup survival, and independent analysis. Additionally, the association of the ARSig with the tumor immune microenvironment, tumor mutational burden (TMB), and therapeutic response in STS were further investigated. Notably, we finally conducted in vitro experiments to verify the findings from the bioinformatics analysis.

Results

A novel ARSig is successfully constructed and validated. The STS with a lower ARSig risk score in the training cohort has an improved prognosis. Also, consistent results were observed in the internal and external cohorts. The receiver operating characteristic (ROC) curve, subgroup survival, and independent analysis further indicate that the novel ARSig is a promising independent prognostic predictor for STS. Furthermore, it is proved that the novel ARSig is relevant to the immune landscape, TMB, immunotherapy, and chemotherapy sensitivity in STS. Encouragingly, we also validate that the signature ARGs are significantly dysregulated in STS, and ARDB2 and SRPK1 are closely connected with the malignant progress of STS cells.

Conclusion

In sum, we construct a novel ARSig for STS, which could act as a promising prognostic factor for STS and give a strategy for future clinical decisions, immune landscape, and personalized treatment of STS.

Primary Malignant Melanotic Nerve Sheath Tumour of the Neck: A Diagnostic Predicament

Primary malignant melanotic nerve sheath tumours, previously called Melanotic schwannomas are rare pigmented tumours of nerve sheath origin, with unspecified biologic behaviour and uncommon presentation in the head and neck region. A primary melanotic schwannoma of the cervical sympathetic plexus, mimicking a cervical lymphadenopathy requires careful evaluation and planning for an optimal outcome. The management of these neoplasms is still controversial, and hence we present a case report with insight into the diagnostic dilemma in work-up of a neck mass that turned out to be a Primary Malignant Melanotic Schwannoma arising from the cervical sympathetic plexus along with a review of literature.

Clinicopathologic and Molecular Characteristics of Epstein-Barr Virus-Associated Smooth Muscle Tumor Compared With Those of Leiomyoma and Leiomyosarcoma

Epstein-Barr virus (EBV)-associated smooth muscle tumors (EBV-SMTs) are rare smooth muscle neoplasms exclusively associated with immunosuppression, such as in patients with HIV/AIDS, posttransplant, and congenital immunodeficiency. However, the genomic landscape of EBV-SMTs is poorly understood. Leiomyosarcomas harbor genomic instability and multiple recurrent DNA copy number alterations, whereas leiomyomas lack such changes. Thus, this study aimed to fill this knowledge gap by characterizing copy number alterations in EBV-SMTs and correlating this information with clinicopathologic characteristics. Our study investigated and compared the pathologic characteristics and copy number profiles of 9 EBV-SMTs (from 7 post-transplant and AIDS patients), 6 leiomyomas, and 7 leiomyosarcomas, using chromosomal microarray platforms. Our results showed a lower copy number alteration burden in EBV-SMTs and leiomyoma than in leiomyosarcoma. This contrast in the molecular profile between EBV-SMTs and leiomyosarcoma is concordant with the different clinical behaviors and pathologic characteristics exhibited by these tumors. Despite having an overall copy number alteration profile closer to leiomyoma, recurrent copy number gain of oncogenes, such as RUNX1, CCND2, and ETS2, was found in EBV-SMTs. Epigenetic alterations may play an important role in tumorigenesis as recurrent copy number gains were found in histone deacetylases. A gene enrichment analysis also demonstrated enrichment of genes involved in the host response to viral infection, suggesting that the tumor immune microenvironment may play an important role in EBV-SMT tumorigenesis.

Imaging of pediatric extremity soft tissue tumors: A COG Diagnostic Imaging Committee/SPR Oncology Committee White Paper

Pediatric soft tissue tumors of the extremity include rhabdomyosarcoma and nonrhabdomyosarcoma neoplasms. This manuscript provides consensus-based imaging recommendations for imaging evaluation at diagnosis, during treatment, and following completion of therapy for patients with a soft tissue tumor of the extremity.

Inflammatory myofibroblastic tumor of the pancreatic neck misdiagnosed as neuroendocrine tumor: A case report

BACKGROUND

Inflammatory myofibroblastic tumor (IMT) is a relatively rare tumor. The global incidence of IMT is less than 1%. There is no specific clinical manifestation. It usually occurs in the lungs, but the pancreas is not the predilection site.

CASE SUMMARY

We present a case of a male patient, 51 years old, who was diagnosed with a pancreatic neck small mass on ultrasound one year ago during a physical examination. As he had no clinical symptoms and the mass was relatively small, he did not undergo treatment. However, the mass was found to be larger on review, and he was referred to our hospital. Since the primal clinical diagnosis was pancreatic neuroendocrine tumor, the patient underwent surgical treatment. However, the case was confirmed as pancreatic IMT by postoperative pathology.

CONCLUSION

Pancreatic IMT is relatively rare and easily misdiagnosed. We can better under-stand and correctly diagnose this disease by this case report.

Unusual case of inflammatory rhabdomyoblastic tumor in a pediatric patient

Inflammatory rhabdomyoblastic tumor (IRMT) is a rare, recently described skeletal muscle neoplasm of uncertain malignant potential. We report an unusual tumor in the right arm of a 5-year-old boy, which is the first case of a pediatric IRMT. Immunohistochemically, most cells in the tumor were positive for CD163 and CD68 staining. The neoplastic cells themselves showed a skeletal muscle phenotype with a diffuse expression of desmin and a focal expression of myoD1. Mitotic activity was low (1/10 HPF), and no necrosis was observed.

Specific Features of Focal Cortical Dysplasia in Tuberous Sclerosis Complex

Patients with tuberous sclerosis complex present with cognitive, behavioral, and psychiatric impairments, such as intellectual disabilities, autism spectrum disorders, and drug-resistant epilepsy. It has been shown that these disorders are associated with the presence of cortical tubers. Tuberous sclerosis complex results from inactivating mutations in the TSC1 or TSC2 genes, resulting in hyperactivation of the mTOR signaling pathway, which regulates cell growth, proliferation, survival, and autophagy. TSC1 and TSC2 are classified as tumor suppressor genes and function according to Knudson's two-hit hypothesis, which requires both alleles to be damaged for tumor formation. However, a second-hit mutation is a rare event in cortical tubers. This suggests that the molecular mechanism of cortical tuber formation may be more complicated and requires further research. This review highlights the issues of molecular genetics and genotype-phenotype correlations, considers histopathological characteristics and the mechanism of morphogenesis of cortical tubers, and also presents data on the relationship between these formations and the development of neurological manifestations, as well as treatment options.

Application of Indocyanine Green Fluorescence Imaging in Assisting Biopsy of Musculoskeletal Tumors

(1) Background: Biopsies are the gold standard for the diagnosis of musculoskeletal tumors. In this study, we aimed to explore whether indocyanine green near-infrared fluorescence imaging can assist in the biopsy of bone and soft tissue tumors and improve the success rate of biopsy. (2) Method: We recruited patients with clinically considered bone and soft tissue tumors and planned biopsies. In the test group, indocyanine green (0.3 mg/kg) was injected. After identifying the lesion, a near-infrared fluorescence camera system was used to verify the ex vivo specimens of the biopsy in real time. If the biopsy specimens were not developed, we assumed that we failed to acquire lesions, so the needle track and needle position were adjusted for the supplementary biopsy, and then real-time imaging was performed again. Finally, we conducted a pathological examination. In the control group, normal biopsy was performed. (3) Results: The total diagnosis rate of musculoskeletal tumors in the test group was 94.92% (56/59) and that in the control group was 82.36% (42/51). In the test group, 14 cases were not developed, as seen from real-time fluorescence in the core biopsy, and then underwent the supplementary biopsy after changing the puncture direction and the location of the needle channel immediately, of which 7 cases showed new fluorescence. (4) Conclusions: Using the near-infrared fluorescence real-time development technique to assist the biopsy of musculoskeletal tumors may improve the accuracy of core biopsy and help to avoid missed diagnoses, especially for some selected tumors.

Incidence and Risk Factors for Extremity Osteoradionecrosis after Limb-Sparing Surgery and Adjuvant Radiotherapy

Osteoradionecrosis (ORN) is a major complication after radiotherapy. Most studies on ORN have focused on patients with mandibular lesions, with few studies including patients with extremity soft tissue sarcoma (STS). We included 198 patients with extremity STS who underwent limb-sparing surgery and adjuvant radiotherapy between 2004 and 2017. The incidence rate of extremity ORN was 3.5% (7/198), with most lesions (6/7) located in the lower extremities. The mean follow-up time was 62 months. Clinical presentations included chronic ulcers, soft tissue necrosis, sinus discharge, bone nonunion, and pathological fractures. Compared with the non-ORN group, the ORN group had a significantly higher total radiation dose (68 Gy vs. 64 Gy, p = 0.048) and greater use of intraoperative periosteal stripping (p = 0.008). Repeat surgeries and subsequent soft tissue reconstruction or limb amputation were performed as treatments. The risk and management of ORN in patients with extremity STS was ignored previously. Because the disease is complex and affects both clinicians and patients, careful surveillance should be undertaken.

MRI Evaluation of Soft Tissue Tumors and Tumor-Like Lesions of Extremities

AIM

The current study aimed to evaluate the use of magnetic resonance imaging (MRI) in the diagnosis of extremity soft tissue tumors and tumor-like abnormalities.

METHODS

This prospective observational study of 71 patients with soft tissue lesions of extremities was conducted at a tertiary hospital and teaching center in western India after obtaining Institutional Ethical Committee (IEC) clearance. All patients underwent an MRI of the region of interest on Siemens Magnetom Vida 3 Tesla MRI (Erlangen, Germany). MRI findings and diagnosis were correlated clinically and with histopathological examination.

RESULTS

A total of 71 patients (49 males and 22 females) in the age group of six to 90 years were included in our study. Out of 44 patients with soft tissue tumors, the most common lesion was neurofibroma (18.1%), followed by lipoma and undifferentiated sarcoma (9.1% each). Liposarcoma, myxoid liposarcoma, giant cell tumor of the tendon, pigmented villonodular synovitis, and schwannoma were seen in 4.5% of patients each. The soft tissue tumor-like lesions were seen in 27 (38%) patients, the most common being slow-flow vascular malformation, which was seen in 9/27 (33%) patients. The second most common pathology was actinomycosis, seen in four (14.8%) patients. Out of 44 patients with soft tissue tumors, 27 (61.4%) were benign and 17 (38.6%) were malignant. Tumor size of more than 5 cm was more commonly seen in malignant tumors (70.5%) than benign tumors (40.7%). The smooth margin was more common in benign tumors (70.3), while most malignant tumors (70.5%) had irregular or lobulated margins. Heterogenous enhancement was more common in malignant tumors (82.3%) than benign tumors (62.9). The odds of a benign histopathological diagnosis for a tumor suspected to be benign by MRI were 93.75 times higher than the odds of a benign histopathological diagnosis for a tumor suspected to be malignant by MRI.

CONCLUSION

MRI is extremely useful in the evaluation of different soft tissue masses and helps in evaluating the characteristics of the masses, their extent and relationship to surrounding structures, and bone destruction, multiplicity, composition, and enhancement pattern. The systematic imaging analysis approach helps to differentiate a benign lesion from a malignant lesion and also in differentiating various soft tissue tumor mimics.