Shared decision making in primary malignant bone tumour surgery around the knee in children and young adults: protocol for a prospective study

BACKGROUND

Children and young adults needing surgery for a primary malignant bone tumour around the knee face a difficult, life-changing decision. A previous study showed that this population wants to be involved more in the decision-making process and that more involvement leads to less decisional stress and regret. Therefore, a well-designed and standardized decision-making process based on the principles of shared decision-making needs to be designed, implemented, and evaluated.

METHODS

We developed a shared decision-making (SDM) model for this patient population, including an online decision aid (DA). This model has been implemented in the standard care of patients with a primary malignant bone tumour around the knee. Following implementation, we will analyse its effect on the decision-making process and the impact on patient experiences using questionnaires and interviews. Moreover, potential areas for improvement will be identified.

DISCUSSION

Given the importance of involving patients and parents in surgical decision-making, particularly in life-changing surgery such as malignant bone tumour surgery, and given the lack of SDM models applicable for this purpose, we want to share our model with the international community, including our study protocol for evaluating and optimising the model. This study will generate valuable knowledge to facilitate the optimisation of current patient care for local treatment. The sharing of our implementation and study protocol can serve as an example for other centres interested in implementing SDM methods in an era characterized by more empowered patients and parents who desire autonomy and reliable and realistic information.

Ewing's Sarcoma of Maxillary Sinus

Ewing's sarcoma is a small round cell tumor commonly involving long bones. Head and neck involvement is seen less frequently with maxillary sinus being the rarest site. Here we report a case of a12-year-old female patient presented with left side facial swelling for 3 weeks duration which was diffuse and hard on palpation. CT and MRI of Nose & para nasal sinus revealed a mass lesion in the left maxillary sinus infiltrating and eroding the orbital wall and extending intracranially. Biopsy from the lesion revealed Ewing's sarcoma with strong positivity for CD-99 marker. Patient was referred to radiotherapy due to extensive disease at younger age. The CT and MRI along with HPE and IHC markers enables early diagnosis and prompt treatment that leads to better survival and prognosis, as unlike Ewing's sarcoma of long bones, that metastasize early. The combined chemoradiotherapy is now the standard line of treatment along with close follow up for at least 2 years.

Incidence trends, overall survival, and metastasis prediction using multiple machine learning and deep learning techniques in pediatric and adolescent population with osteosarcoma and Ewing's sarcoma: nomogram and webpage

OBJECTIVE

The objective of this study was to analyze the incidence and overall survival (OS) of osteosarcoma (OSC) and Ewing's sarcoma (EWS) in a pediatric and adolescent population, employing machine learning (ML) and deep learning (DL) models to predict the likelihood of metastasis.

METHODS

Involving 2465 OSC and 1373 EWS patients aged 0-19 years, from 2004 to 2020. ML techniques-Lasso, Ridge Regression, Elastic Net, and Random Forest-were used alongside a deep learning model based on TensorFlow and Keras, to construct predictive models for metastasis. These models were optimized using grid search with cross-validation and evaluated on their performance metrics, including AUC, sensitivity, and accuracy. The variables' importance in metastasis prediction was determined using SHAP values. Statistical analysis was performed using R software, and an online nomogram was developed for clinical use.

RESULTS

The age-adjusted incidence of OSC and EWS from 2004 to 2020 showed a significant uptrend. The deep learning model, iterated 50 times, outperformed the Random Forest model in both loss and accuracy stabilization. The nomogram created demonstrated accurate survival predictions, as evidenced by its calibration curves and the distinction between high and low-risk groups.

CONCLUSION

The increasing trend in age-adjusted incidence of OSC and EWS highlights the need for continued research and improved therapeutic strategies in this domain. The study employed ML and DL models to predict distant metastasis in pediatric and adolescent patients with OSC and EWS, providing a valuable tool for prognosis. The online nomogram developed as a part of this research enhances the models' clinical utility, offering an accessible means for clinicians to predict survival outcomes effectively.

Beyond Bones: Exploring Primitive Neuroectodermal Tumor of Kidney

A primitive neuroectodermal tumor (PNET), classified as a malignancy of the Ewing's sarcoma family of tumors, is typically observed in bones or soft tissue among adolescents and young adults. However, its occurrence outside the skeletal system (extra-osseous location), particularly within visceral organs, is infrequent. Renal PNET is exceptionally uncommon and exhibits an exceedingly aggressive biological behavior, leading to a dismal prognosis as compared to conventional renal cell carcinoma. In this report, we present the case of a 28-year-old adult male patient diagnosed with renal PNET on ultrasound-guided biopsy, who initially presented with left flank pain and recent onset of hematuria within a brief timeframe. Left radical nephrectomy followed by postoperative VDC-IE (combined vincristine, doxorubicin, and cyclophosphamide followed by another combination of ifosfamide and etoposide) chemotherapy was given to the patient. This case serves as a reminder to nephrologists, medical oncologists, and pathologists that in adolescents and young adults presenting with suspicious renal masses, a diagnosis of renal PNET should always be considered. Timely surgical intervention, coupled with chemotherapy, is essential for optimal therapeutic management and improved prognosis in cases of such rare and aggressive malignancies.

Primitive Neuroectodermal Tumour of the Larynx: A Rare Case Report

Ewing's sarcoma/primitive neuroectodermal tumour is a malignant small round blue cell tumour of neuroectodermal origin that affects bones and soft tissue in children and young adults. These are aggressive malignant tumours, and long-term survival rates following diagnosis remain poor. Occurrence of primitive neuroectodermal tumours in the head and neck region is uncommon. It is extremely rare in the larynx with only 12 cases reported in the literature. We report a case of primary primitive neuroectodermal tumour of the larynx in a 28-year-old female. She presented with hoarseness of voice, and her computed tomography and laryngoscopy revealed a mass at the laryngeal inlet. A biopsy followed by histopathology and immunohistochemistry confirmed the diagnosis of a primitive neuroectodermal tumour. She initially defaulted from treatment and subsequently presented with stridor for which an emergency tracheostomy was done. Her metastatic workup did not reveal any lesion elsewhere. So, a diagnosis of a primary primitive neuroectodermal tumour of the larynx was made, and the patient was started on treatment.

Pediatric Extra-skeletal Sinonasal Ewing's Sarcoma: Report of Two Cases with Literature Review

Ewing's sarcoma is a malignant small round cell tumor that belongs to the primitive class of neuroectodermal tumors. Ewing's sarcoma generally arises in the long bones of the extremities, and sinonasal localization of Ewing's sarcoma in pediatric population is an extremely rare event. The combination of histopathological examination and ancillary methods is extremely important to establish the diagnosis of Ewing's sarcoma. The treatment for Ewing's sarcoma includes a multidisciplinary approach with surgery, radiotherapy, and chemotherapy. Through this report, we try to communicate our experience and highlight the challenges encountered in diagnosing and approaching two extremely rare cases of pediatric sinonasal Ewing's sarcoma.

Primary endobronchial multifocal Ewing's sarcoma: a rare case report

Extraskeletal Ewing's sarcoma (ES) has been reported to originate from various sites. Primary endobronchial ES is an extremely rare bronchial tumor, especially multifocal lesions. This report describes a rare presentation of primary bronchial ES in a 31-year-old female who was referred to the emergency department of our hospital due to suspicion of a foreign body in the bronchus. Computed tomography and bronchoscopy revealed multiple polypoid nodules in the middle bronchus of her right lung, thus excluding the initial diagnosis. Infection-related laboratory tests and serum tumor markers were normal. The bronchial sleeve resection was performed to remove the tumor completely and the patient's clinical symptoms obviously improved. Subsequent imaging, histopathological, immunohistochemical and genetic analyses made a conclusive diagnosis of primary endobronchial ES. To our knowledge, this is the eighth case of primary bronchial ES reported in medical literature.

A Systematic Review of the Gonadotoxicity of Osteosarcoma and Ewing's Sarcoma Chemotherapies in Postpubertal Females and Males

Data on gonadotoxicity of chemotherapies are essential to better counsel young females and males about the risk of infertility and to better indicate fertility preservation measures before cancer therapies. However, such data have not recently been reviewed for bone cancer. Therefore, a systematic literature search was conducted considering papers published since 2000. This study is part of the FertiTOX® project, which aims to improve the lack of data regarding gonadotoxicity of cancer therapies to enable more accurate counseling regarding fertility preservation. Only relapse-free women and men were included. Gonadotoxic therapy-induced suspected infertility was defined as very low anti-mullerian hormone, high gonadotropin concentration, amenorrhea, oligomenorrhea, azoospermia, or oligozoospermia. The quality of the individual studies was assessed using the Newcastle-Ottawa Scale (NOS). In total, 11 out of 831 studies were included in the review. Suspected infertility was found in 10/190 (5.1%, range 0%-66%) of female patients with osteosarcoma (six studies), in 24/46 (52.2%, range 46%-100%) of male patients with osteosarcoma (three studies), in 18/138 (13.0%, range 3%-18%) of female patients with Ewing's sarcoma (three studies), and in 34/38 (89.5%) of male patients with Ewing's sarcoma (one study). A risk calculation in relation to specific chemotherapies was not possible. Risk of suspected infertility tends to be higher in Ewing's sarcoma in which all patients received chemotherapies with alkylating agents. Two of the 11 included studies received a high NOS quality score, whereas the remaining nine studies received a low quality score, mainly because of the lack of a comparator group. Published data are too limited for precise estimation of the gonadotoxicity. However, data indicate clinically relevant risk for infertility, supporting counseling patients before chemotherapy about fertility preservation measures.

Preserved walking function without postoperative reconstruction for pelvic Ewing's sarcoma: a case report

BACKGROUND

Ewing's sarcoma is a primary bone tumor predominantly observed in children and adolescents, necessitating a multidisciplinary treatment approach. While localized cases have a 5-year survival rate of 60-70%, the prognosis is significantly worse in pelvic advanced cases with metastasis. Moreover, pelvic Ewing's sarcoma has the unique problem of leading to high rates of postoperative infection.

CASE PRESENTATION

We present the case of a Japanese 14-year-old boy with left iliac Ewing's sarcoma and multiple metastases. At the initial visit, imaging revealed a large tumor in the left iliac bone with extraosseous extension and metastasis to multiple sites. Neoadjuvant chemotherapy resulted in significant tumor reduction. Surgical resection was performed without pelvic ring reconstruction to enable early postoperative chemotherapy and minimize postoperative infection risk. Despite complete abductor muscle removal, the patient achieved a stable gait postoperatively by centering the load axis.

CONCLUSION

Our case highlights the successful management of a left iliac Ewing's sarcoma with multiple metastases, with a focus on functional preservation and infection risk reduction. Pelvic ring reconstruction was not performed to avoid postoperative complications, emphasizing the importance of early postoperative chemotherapy. The patient achieved a stable gait postoperatively, demonstrating the potential benefits of this approach in similar cases.

Gene signatures of copper metabolism related genes may predict prognosis and immunity status in Ewing's sarcoma

Background

Cuproptosis is copper-induced cell death. Copper metabolism related genes (CMRGs) were demonstrated that used to assess the prognosis out of tumors. In the study, CMRGs were tested for their effect on TME cell infiltration in Ewing's sarcoma (ES).

Methods

The GEO and ICGC databases provided the mRNA expression profiles and clinical features for downloading. In the GSE17674 dataset, 22prognostic-related copper metabolism related genes (PR-CMRGs) was identified by using univariate regression analysis. Subsequently, in order to compare the survival rates of groups with high and low expression of these PR-CMRGs,Kaplan-Meier analysis was implemented. Additionally, correlations among them were examined. The study employed functional enrichment analysis to investigate probable underlying pathways, while GSVA was applied to evaluate enriched pathways in the ES (Expression Set). Through an unsupervised clustering algorithm, samples were classified into two clusters, revealing significant differences in survival rates and levels of immune infiltration.

Results

Using Lasso and step regression methods, five genes (TFRC, SORD, SLC11A2, FKBP4, and AANAT) were selected as risk signatures. According to the Kaplan-Meier survival analysis, the high-risk group had considerably lower survival rates than the low-risk group(p=6.013e-09). The area under the curve (AUC) values for the receiver operating characteristic (ROC) curve were 0.876, 0.883, and 0.979 for 1, 3, and 5 years, respectively. The risk model was further validated in additional datasets, namely GSE63155, GSE63156, and the ICGC datasets. To aid in outcome prediction, a nomogram was developed that incorporated risk levels and clinical features. This nomogram's performance was effectively validated through calibration curves.Additionally, the study evaluated the variations in immune infiltration across different risk groups, as well as high-expression and low-expression groups. Importantly, several drugs were identified that displayed sensitivity, offering potential therapeutic options for ES.

Conclusion

The findings above strongly indicate that CMRGs play crucial roles in predicting prognosis and immune status in ES.

Innovative Approach to Chest Wall Reconstruction Using Autologous Tissue - The Fascia Lata in Pediatric Patients

Chest wall reconstruction poses significant challenges. One of those challenges is choosing the correct material for reconstruction. There is debate on using prosthetic materials versus autologous tissues and rigid versus nonrigid materials. This article showcases the novel use of fascia lata for chest wall reconstruction in children.

Cold Physical Plasma Reduces Motility of Various Bone Sarcoma Cells While Remodeling the Cytoskeleton

BACKGROUND/AIM

Cold physical plasma (CPP) has emerged as an effective therapy in oncology by inducing cytotoxic effects in various cancer cells, including chondrosarcoma (CS), Ewing's sarcoma (ES), and osteosarcoma (OS). The current study investigated the impact of CPP on cell motility in CS (CAL-78), ES (A673), and OS (U2-OS) cell lines, focusing on the actin cytoskeleton.

MATERIALS AND METHODS

The CASY Cell Counter and Analyzer was used to study cell proliferation and determine the optimal concentrations of fetal calf serum to maintain viability without stimulation of cell proliferation. CellTiter-BlueCell viability assay was used to determine the effects of CPP on the viability of bone sarcoma cells. The Radius assay was used to determine cell migration. Staining for Deoxyribonuclease I, G-actin, and F-actin was used to assay for the effects on the cytoskeleton.

RESULTS

Reductions in cell viability and motility were observed across all cell lines following CPP treatment. CPP induced changes in the actin cytoskeleton, leading to decreased cell motility.

CONCLUSION

CPP effectively reduces the motility of bone sarcoma cells by altering the actin cytoskeleton. These findings underscore CPP's potential as a therapeutic tool for bone sarcomas and highlight the need for further research in this area.

Unlocking epigenetics for precision treatment of Ewing's sarcoma

Ewing's sarcoma (EWS) is a highly aggressive malignant bone tumor primarily affecting adolescents and young adults. Despite the efficacy of chemoradiotherapy in some cases, the cure rate for patients with metastatic and recurrent disease remains low. Therefore, there is an urgent need for innovative therapeutic approaches to address the challenges associated with EWS treatment. Epigenetic regulation, a crucial factor in physiological processes, plays a significant role in controlling cell proliferation, maintaining gene integrity, and regulating transcription. Recent studies highlight the importance of abnormal epigenetic regulation in the initiation and progression of EWS. A comprehensive understanding of the intricate interactions between EWS and aberrant epigenetic regulation is essential for advancing clinical drug development. This review aims to provide a comprehensive overview of both epigenetic targets implicated in EWS, integrating various therapeutic modalities to offer innovative perspectives for the clinical diagnosis and treatment of EWS.

Machine Learning Predict Survivals of Spinal and Pelvic Ewing's Sarcoma with the SEER Database

STUDY DESIGN

Retrospective Cohort Study.

OBJECTIVES

This study aimed to develop survival prediction models for spinal Ewing's sarcoma (EWS) based on machine learning (ML).

METHODS

We extracted the SEER registry's clinical data of EWS diagnosed between 1975 and 2016. Three feature selection methods extracted clinical features. Four ML algorithms (Cox, random survival forest (RSF), CoxBoost, DeepCox) were trained to predict the overall survival (OS) and cancer-specific survival (CSS) of spinal EWS. The concordance index (C-index), integrated Brier score (IBS) and mean area under the curves (AUC) were used to assess the prediction performance of different ML models. The top initial ML models with best performance from each evaluation index (C-index, IBS and mean AUC) were finally stacked to ensemble models which were compared with the traditional TNM stage model by 3-/5-/10-year Receiver Operating Characteristic (ROC) curves and Decision Curve Analysis (DCA).

RESULTS

A total of 741 patients with spinal EWS were identified. C-index, IBS and mean AUC for the final ensemble ML model in predicting OS were .693/0.158/0.829 during independent testing, while .719/0.171/0.819 in predicting CSS. The ensemble ML model also achieved an AUC of .705/0.747/0.851 for predicting 3-/5-/10-year OS during independent testing, while .734/0.779/0.830 for predicting 3-/5-/10-year CSS, both of which outperformed the traditional TNM stage. DCA curves also showed the advantages of the ensemble models over the traditional TNM stage.

CONCLUSION

ML was an effective and promising technique in predicting survival of spinal EWS, and the ensemble models were superior to the traditional TNM stage model.

Ewing's sarcoma of kidney extending into IVC and RA: resection using modified cannulation strategy for CPB

Ewing's sarcoma of the kidney is a rare tumor. Although renal carcinomas are known to involve the inferior cava, extension of the tumor up to the right atrium is not common. In the majority of cases when the tumor extends into the infrahepatic part of the inferior vena cava, it can be removed from the abdominal approach. Few patients require the use of cardiopulmonary bypass for removal of the tumor in the inferior vena cava and right atrium. The management of patients requiring resection of kidney tumors and right atrial mass is more complicated and requires a team approach consisting of oncosurgeons, cardiac surgeons, and cardiac anesthetists. The resection of the kidney tumor with a mass in the right atrium is usually done concomitantly. The cardiopulmonary bypass cannulation strategy needs to be modified in such cases.

Management of Ewing Sarcoma of Distal Fibula in Child: A Case Report

Introduction

Ewing's sarcoma is the second most common primary malignant bone tumor in children and adolescents, after osteosarcoma. It is a rare tumor, with the axial skeleton being the preferred site of development, followed by the long bones. Diagnosis is evoked by imaging and confirmed by histology. Treatment is based on intensive chemotherapy with local surgical treatment in operable forms, and in some cases, radiotherapy. There are only a few sporadic cases in the literature describing distal fibular localization.

Case Report

We report the case of a 7-year-old child who presented with pain on the lateral aspect of the left ankle without local inflammatory signs. Radiological findings revealed a metaphyseal-diaphyseal osteolytic tissue process of the left fibula, and histology concluded that it was Ewing's sarcoma. We proceeded with neoadjuvant polychemotherapy followed by segmental resection of the distal fibula with an anteroexternal tibial rod, plus tibiotalar, and talocalcaneal arthrodesis without recourse to radiotherapy.

Conclusion

The management of Ewing's sarcoma is constantly evolving. Its distal fibular location in a growing limb makes it even more difficult. It must be personalized, multidisciplinary, and carried out in specialized centers.

A rare Ewing-like small round cell tumor in prostate: a case report and literature review

BACKGROUND

Small round cell tumor (SRCT) is a group of malignancy with similar optical microscopic morphology. Despite its low incidence, SRCT has a high malignant degree and poor prognosis. Besides, atypical clinical symptoms make it difficult in preoperative diagnosis.

CASE REPORT

A 67-year-old man was presented to the outpatient service with dysuria and weak urine stream lasting for 3 months. After oral treatment with tamsulosin and finasteride for 2 months, the symptoms worsen. Transurethral prostate holmium laser enucleation was operated and postoperative pathology result revealed small blue round cell malignant tumor. Further immunohistochemistry and fluorescence in situ hybridization examination indicated Ewing-like SRCT. So a Da Vinci Robotic prostatectomy was performed further and whole-genome sequencing was conducted. Several gene mutations including RAF1, ARID1A, SMARCA4, and BCL2L11 were found but no FDA-approved drug could treat specifically. Then the patient received Ewing-type therapeutic regimens treatment and has been followed up to date (over 24 months).

CONCLUSION

Because of its non-elevated serum PSA level, prostate SRCT is often ignored as a possibility of malignant tumor and regarded as benign prostatic hyperplasia (BPH). The possibility of prostate SRCT need to be considered if dysuria symptoms could not alleviate significantly after a period of oral treatment.

Primary intradural extraosseous Ewing's sarcoma of the L3 nerve root: illustrative case

BACKGROUND

Ewing's sarcoma is an uncommon, aggressive malignancy that typically presents as an osseous lesion, most commonly in children and adolescents. Very rarely Ewing's sarcoma can present as an intradural extramedullary mass mimicking more common tumors.

OBSERVATIONS

A 32-year-old female had a left L3 nerve root-associated lesion identified in the setting of recent-onset radiculopathy. Contrast-enhanced magnetic resonance imaging of the lumbar spine was favored to demonstrate a schwannoma or neurofibroma. Hemilaminectomy, facetectomy, and resection of the mass led to improved radiculopathy and a tissue diagnosis of Ewing's sarcoma. Immediate referral to medical oncology facilitated expeditious initiation of adjuvant chemotherapy and radiation.

LESSONS

The differential diagnosis for newly identified nerve root-associated tumors should remain broad, including common benign pathologies and rare malignant entities. Tissue remains the gold standard for diagnosis, as preoperative imaging suggested a nerve sheath tumor. Malignant pathologies such as Ewing's sarcoma must be considered, especially in the setting of rapidly progressive symptoms or interval growth on serial imaging. Early diagnosis allows for the timely initiation of comprehensive oncological care. Long-term multidisciplinary follow-up is necessary for the surveillance of disease progression.

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.

En bloc resection followed by gluteal advancement flap for sacral Ewing's sarcoma: A novel technique

Ewing's sarcoma is a rare and highly aggressive bone tumor primarily affecting children and adolescents. It commonly presents in the pelvic and axial skeleton, with sacral involvement posing unique challenges due to its intricate anatomical location. This report details the case of an 18-year-old male with sacral Ewing's sarcoma, emphasizing the diagnostic, surgical, and reconstructive aspects of management. The patient presented with lower back pain, lower limb weakness, and urinary incontinence, which prompted an extensive diagnostic evaluation. Magnetic resonance imaging and computed tomography scans revealed a large lytic mass extending from the S2 vertebra to the coccyx invading the presacral space. Biopsy confirmed the diagnosis of Ewing's sarcoma, characterized by the EWS-FLI1 type 1 translocation. A multidisciplinary team comprising neurosurgeons, colorectal surgeons, and plastic surgeons was formulated. En bloc resection of the tumor, lumbopelvic fixation, and soft-tissue reconstruction using bilateral gluteus maximus advancement flaps were successfully performed. The procedure aimed to address both the oncological and functional aspects of the patient's condition. Chemotherapy and radiotherapy were administered as adjuvant therapies. At 2-year follow-up, the patient was ambulating independently with no residual tumor on imaging. This case highlights the complex nature of sacral Ewing's sarcoma and underscores the importance of a multidisciplinary approach. The described surgical technique, including the innovative use of gluteus maximus advancement flaps for soft-tissue reconstruction, contributes to reducing wound complications and promoting successful patient outcomes. The presented approach serves as a valuable addition to the armamentarium of treatment options for this challenging malignancy.

The Small Round Blue Cell Tumors of Sinonasal Tract: Pathologists Grey Zone

Background

One of the most challenging diagnostic categories in the sinonasal tract includes small-blue-round-cell tumors. These are malignant tumors which show many overlapping histomorphology and immunohistochemistry (IHC) findings. Limited, small biopsy of these not completely excisable tumors adds to the diagnostic confusion.

Materials and Methods

A cross-sectional study was done for 2 years (January 2018-December 2020) in a tertiary care institute, which included 70 cases of tumors of which 49 cases were malignant. All paraffin-embedded blocks were subjected to hematoxylin and eosin stain and IHC followed by molecular study wherever needed.

Results

Of the total cases, small-blue-round-cell tumor constituted the major category comprising 20 rare and interesting cases which included sinonasal undifferentiated carcinoma (4 cases), malignant lymphoma (2 cases of diffuse large B-cell lymphoma and 2 cases of extranodal natural killer/T-cell lymphoma), rhabdomyosarcoma (2 cases), olfactory neuroblastoma (2 cases), malignant melanoma (2 cases), plasmacytoma (2 cases), atypical Ewing's sarcoma (EWS) (1 case), EWS (1 case), nuclear protein in testis (NUT) carcinoma (1 case), and small-cell neuroendocrine carcinoma (1 case).

Conclusion

Tumors of the sinonasal tract are very diverse, more so in small-round-cell tumor which present with a undifferentiated morphology. Thus, accurate diagnosis needs clinicoradiological parameters and special ancillary techniques such as IHC and molecular study in addition to histopathology for early diagnosis and therapy to prevent significant morbidity and mortality caused in these tumors.

Categorizing Malignant Small Round Cell Tumors in Aspiration Cytology: An Institutional Experience

Aim and Objectives

The study aims to categorize malignant small round cell tumors (MSRCTs) originating in various sites of the body with the objective of utilization of cytomorphological features and ancillary techniques.

Study Design

It is a cross-sectional study conducted over a time span of 3 years (2017-2020). 33 cases of tumors with round cell morphology were evaluated by fine needle aspiration cytology (FNAC).

Materials and Methods

The application of cell block preparation supported by immunohistochemistry aided in the categorization of 23 cases with definite diagnosis and the rest were reported as MSRCTs.

Results

Among the categorized 23/33 cases, the most common diagnosis was Ewing's sarcoma (7/23) followed by 6 cases of lymphoma. There were 2 cases each of rhabdomyosarcoma and Langerhans cell histiocytosis (LCH) and 1 case each of neuroblastoma, desmoplastic small round cell tumor (DSRCT), myeloid sarcoma, neuroendocrine tumor of pancreas, plasmacytoma, and small cell carcinoma. Histopathology confirmation was available in 24/33 cases. Among the categorized tumors (23/33), biopsy correlation was available in 19 cases, of which concordant result was seen in 17 cases (89.47%), which were 6 cases of lymphoma, 5 cases of Ewing's sarcoma (EWS), 2 of rhabdomyosarcoma, and 1 each of neuroblastoma, small cell carcinoma, DSRCT, and LCH. Discordant result was seen in one case of rhabdomyosarcoma and a case of synovial sarcoma reported as extraskeletal EWS in cytology. Out of the uncategorized cases reported as MSRTCs, histopathology was available in 5 cases which were diagnosed as rhabdomyosarcoma (1 cases), lymphoma (1 case), amelanotic melanoma (1 case), and extraskeletal EWS (2 cases).

Conclusion

Categorization of MSRCTs should be done to implement appropriate therapeutic protocol. FNAC provides a rapid diagnosis contributing immensely for the timely management of the patient. Detailed cytomorphological evaluation serves as a guide for further evaluation by ancillary techniques leading to definitive diagnosis.

Primary Ewing's Sarcoma of the Sternum in an Adult Male: A Rare Case Report

Ewing's sarcoma, a rare primary bone malignancy primarily affecting adolescents and young adults, typically manifests in the pelvic bones and femur. Primary Ewing's sarcoma of the sternum is exceptionally rare, constituting less than 1% of cases. We present a case of a 34-year-old man with a 2-month history of anterior chest wall pain initially attributed to muscular spasm. Subsequently, the patient developed a palpable mass and imaging demonstrated a mid-lower sternal lesion with cortical destruction and soft tissue involvement, confirmed as Ewing's sarcoma on biopsy. In addition, a suspicious lesion was identified in the left distal tibia, which was histologically confirmed as a metastasis from the primary sternal sarcoma. Neoadjuvant chemotherapy preceded partial sternotomy with rib resection and reconstruction, achieving clear surgical margins. Postoperative evaluation showed shrinkage in the sternal lesion and near-resolution of the tibial metastasis. Subsequent chemotherapy cycles resulted in no evidence of the disease on the follow-up positron emission tomography scan. This case underscores the diagnostic challenges of primary sternal Ewing's sarcoma and emphasizes the importance of early recognition and comprehensive evaluation in managing such rare presentations.

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.

PARP inhibitor combinations with high-dose vitamin C in the treatment of Ewing sarcoma: two case reports and mechanistic overview

Ewing's sarcoma (ES) is a bone and soft tissue tumor that mainly occurs at a young age. The underlying cause of Ewing's sarcoma is the formation of fusion proteins between FET family genes and ETS family genes. Tumors with FET/ETS fusion genes can have defects in the DNA damage response and are sensitive to PARP inhibitors (PARPi). However, several studies have shown that PARPi alone is not sufficient to induce a meaningful antitumor response and that combinations of DNA-damaging agents with PARPi are required to achieve efficacy. Accordingly, preclinical studies have reported dramatic responses to PARPi treatment in combination with DNA-damaging agents such as temozolomide or irinotecan. Similarly, it has been previously reported that by generating reactive oxygen species, high-dose intravenous vitamin C (IVC) can induce DNA damage. This suggests that the combination of IVC with PARPi may increase genotoxic stress and enhance the antitumor response. In addition, unlike chemotherapeutic agents, IVC induces DNA damage selectively in cancer cells, and the side effects are significantly milder than those of chemotherapy. As ETS fusion-positive ES is deficient in faithful DNA repair, partly due to the interaction between ETS fusion products and PARP1, a PARPi plus IVC seems to be a logical and effective combination for the treatment of ETS fusion-positive ES. This paper reports significant responses to IVC (1-1.5 g/kg) in combination with PARPi (olaparib 300 mg BID or talazoparib 1 mg/day) in two patients with metastatic Ewing's sarcoma. The observations highlight an unmet therapeutic need for patients with advanced metastatic ES. The combination of PARPi with a selective DNA-damaging agent was effective in these cases. This case experience suggests that IVC may be incorporated into PARPi-based therapeutic strategies. Further studies are needed to confirm the efficacy of this combination in the treatment of Ewing sarcoma with ETS fusions.