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

Not All Leiomyosarcomas Are the Same: How to Best Classify LMS

OPINION STATEMENT

Leiomyosarcoma arises from smooth muscle and represents one of the most common soft tissue sarcomas. Despite aggressive multimodality care, over half of the patients will ultimately develop metastatic and incurable disease with a median survival of 12-18 months. At present, there is no standard system to classify leiomyosarcoma, which itself is a heterogeneous disease. Classification by tumor location is the most simplistic approach and is most frequently utilized in clinical practice. Tumor location impacts diagnosis (recognition pre-operatively versus at the time of surgery) as well as treatment (ability to completely resect with clear margins with minimal morbidity). While tumor location can impact prognosis, for example, extremity tumors would generally be considered as lower risk than inferior vena cava tumors, leiomyosarcoma can exhibit a heterogeneous behavior irrespective of tumor location. Specifically, some patients have rapidly progressing disease despite aggressive chemotherapy, while others display a more indolent course even in the metastatic setting. The pathogenic drivers of the heterogeneity observed in tumor behavior are not well understood. As we learn more about the molecular composition of leiomyosarcoma, various classification groups have been proposed as discussed here. Ultimately, it is unlikely that one variable will be adequate for tumor classification, and a combination of location and molecular composition will be necessary to develop appropriate risk stratification nomograms and treatment strategies.

New established cell lines from undifferentiated pleomorphic sarcoma for in vivo study

As a high-grade soft-tissue sarcoma (STS), undifferentiated pleomorphic sarcoma (UPS) is highly recurrent and malignant. UPS is categorized as a tumor of uncertain differentiation and has few options for treatment due to its lack of targetable genetic alterations. There are also few cell lines that provide a representative model for UPS, leading to a dearth of experimental research. Here, we established and characterized new cell lines derived from two recurrent UPS tissues. Cells were obtained from UPS tissues by mincing, followed by extraction or dissociation using enzymes and culture in a standard culture environment. Cells were maintained for several months without artificial treatment, and some cell clones were found to be tumorigenic in an immunodeficient mouse model. Interestingly, some cells formed tumors in vivo when injected after aggregation in a non-adherent culture system for 24 h. The tissues from in vivo study and tissues from patients shared common histological characteristics. Pathways related to the cell cycle, such as DNA replication, were enriched in both cell clones. Pathways related to cell-cell adhesion and cell-cell signaling were also enriched, suggesting a role of the mesenchymal-to-epithelial transition for tumorigenicity in vivo. These new UPS cell lines may facilitate research to identify therapeutic strategies for UPS. [BMB Reports 2023; 56(4): 258-264].

Extramedullary Hematopoiesis Adjacent to Vertebral Fracture in a Patient with Pernicious Anemia: Support for a Mechanical Extrusion Mechanism

CASE

A 68-year-old woman presented with a paraspinal mass of indeterminate imaging characteristics. Workup and computed tomography-guided Fine Needle Aspiration (FNA) aspiration revealed extramedullary hematopoiesis (EMH) adjacent to a prior compression fracture in the setting of pernicious anemia.

CONCLUSION

The combination of findings suggests a possible relationship of the compression fracture and the EMH because of traumatic extravasation of marrow contents, with the patient's underlying anemia possibly providing an underlying predisposition to EMH.

Characteristics, Natural Course and Treatment of Intramuscular Capillary-type Haemangioma: A Systematic Literature Review

Intramuscular capillary-type haemangiomas (ICTH) are rare vascular anomalies that can easily be misdiagnosed as other entities. A systematic review was performed of all cases of ICTH in the literature since its first description in 1972. An adjudication committee reviewed cases to include only ICTHs. Among 1,143 reports screened, 43 were included, involving 75 patients. The most frequent differential diagnosis was intramuscular venous malformations. The mean age of patients at diagnosis was 21.2 years. ICTH was mainly described as a gradually increasing mass (81.8%), painless (73.9%), that could occur anywhere in the body but most frequently on the head and neck (44.0%). Magnetic resonance imaging (MRI) was mainly used for diagnosis (69.1%) and displayed specific features. The most frequent treatment was complete surgical removal (73.9%), which could be preceded by embolization, and led to complete remission without recurrence in all but 1 case.

Biological Role and Clinical Implications of MYOD1L122R Mutation in Rhabdomyosarcoma

Major progress in recent decades has furthered our clinical and biological understanding of rhabdomyosarcoma (RMS) with improved stratification for treatment based on risk factors. Clinical risk factors alone were used to stratify patients for treatment in the European Pediatric Soft Tissue Sarcoma Study Group (EpSSG) RMS 2005 protocol. The current EpSSG overarching study for children and adults with frontline and relapsed rhabdomyosarcoma (FaR-RMS NCT04625907) includes FOXO1 fusion gene status in place of histology as a risk factor. Additional molecular features of significance have recently been recognized, including the MYOD1^L122R gene mutation. Here, we review biological information showing that MYOD1^L122R blocks cell differentiation and has a MYC-like activity that enhances tumorigenesis and is linked to an aggressive cellular phenotype. MYOD1^L122R mutations can be found together with mutations in other genes, such as PIK3CA, as potentially cooperating events. Using Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, ten publications in the clinical literature involving 72 cases were reviewed. MYOD1^L122R mutation in RMS can occur in both adults and children and is frequent in sclerosing/spindle cell histology, although it is also significantly reported in a subset of embryonal RMS. MYOD1^L122R mutated tumors most frequently arise in the head and neck and extremities and are associated with poor outcome, raising the issue of how to use MYOD1^L122R in risk stratification and how to treat these patients most effectively.

Advances in The Application and Research of Magnetic Resonance Diffusion Kurtosis Imaging in The Musculoskeletal System

Magnetic resonance diffusion kurtosis imaging (DKI) is an emerging magnetic resonance imaging (MRI) technique that can reflect microstructural changes in tissue through non-Gaussian diffusion of water molecules. Compared to traditional diffusion weighted imaging (DWI), the DKI model has shown greater sensitivity for diagnosis of musculoskeletal diseases and can help formulate more reasonable treatment plans. Moreover, DKI is an important auxiliary examination for evaluation of the motor function of the musculoskeletal system. This article briefly introduces the basic principles of DKI and reviews the application and research of DKI in the evaluation of disorders of the musculoskeletal system (including bone tumors, soft tissue tumors, spinal lesions, chronic musculoskeletal diseases, musculoskeletal trauma, and developmental disorders) as well as the normal musculoskeletal tissues. EVIDENCE LEVEL: 5 TECHNICAL EFFICACY: 1.

The importance of surgical resection in the management of rectal sarcoma: A national cancer database analysis of 133 cases

BACKGROUND AND PURPOSE

Rectal sarcomas (RS) are rare malignant tumors with a very poor prognosis. This study aimed to assess the characteristics, treatment, and outcomes of RS in the United States.

METHODS

This study was a retrospective analysis of the National Cancer Database (NCDB) from 2004 to 2019 of patients with a diagnosis of RS. The main outcome measures were overall survival (OS) and its predictors.

RESULTS

133 RS patients (39.1% female) with a mean age of 65.7 ± 15.6 years were included in the study. Mean tumor size was 6.1 ± 3 cm. The crude OS rate was 22.5% and median survival duration was 10.1 (IQR: 3.2-21) months. Factors associated with an improved OS on were private insurance (HR = 0.23, p = 0.001) and undergoing surgery (HR 0.23, p < 0.001), Factors associated with poor survival were age (HR 1.02, p = 0.005), male sex (HR 2.27, p = 0.001), Charlson score of 3 (HR 5.17, p = 0.003), and positive resection margins (HR: 2.64, p = 0.01). Multivariate Cox regression analysis revealed that male sex (HR 2.16, p = 0.04) and positive resection margins (HR 2.31, p = 0.03) were predictors of poor survival whereas surgery was an independent predictor of improved OS (HR 0.321, p < 0.001) CONCLUSIONS: RS is a very rare rectal malignancy with an even poorer prognosis than previously reported. However, undergoing surgery with curative intent while obtaining negative margins may confer better OS.

A League of Its Own? Established and Emerging Therapies in Undifferentiated Pleomorphic Sarcoma

OPINION STATEMENT

Over the last decade in soft tissue sarcoma (STS) research, the shifting landscape towards more precise subtype classification and the increasing study of novel therapeutic strategies has prompted a need to highlight current knowledge of effective subtype specific therapies. Undifferentiated pleomorphic sarcoma (UPS), formerly known as malignant fibrous histiocytoma (MFH), is among the most common subtypes of STS arising in the trunk or extremities of adults. Administration of systemic chemotherapy is the primary management in locally advanced and metastatic UPS. While anthracycline-based chemotherapy continues to be standard of care in this setting, outcomes in locally advanced or metastatic UPS remain poor. Recent studies highlight the unique characteristics of UPS that may contribute to its greater sensitivity to immune checkpoint inhibition (ICI) compared to other STS subtypes. With the promise of benefit from novel therapies, including ICI or ICI plus chemotherapy, for a subset of patients with UPS comes the need to identify biomarkers predictive of response to therapy. Ongoing and future clinical trials should place strong emphasis on correlative biomarker studies to learn more about the unique biology of UPS and to identify patients for whom ICI-based therapy will be effective.

The Roles of Exosomes in Metastasis of Sarcoma: From Biomarkers to Therapeutic Targets

Sarcoma is a heterogeneous group of mesenchymal neoplasms with a high rate of lung metastasis. The cellular mechanisms responsible for sarcoma metastasis remain poorly understood. Furthermore, there are limited efficacious therapeutic strategies for treating metastatic sarcoma. Improved diagnostic and therapeutic modalities are of increasing importance for the treatment of sarcoma due to their high mortality in the advanced stages of the disease. Recent evidence demonstrates that the exosome, a type of extracellular vesicle released by virtually all cells in the body, is an important facilitator of intercellular communication between the cells and the surrounding environment. The exosome is gaining significant attention among the medical research community, but there is little knowledge about how the exosome affects sarcoma metastasis. In this review, we summarize the multifaceted roles of sarcoma-derived exosomes in promoting the process of metastasis via the formation of pre-metastatic niche (PMN), the regulation of immunity, angiogenesis, vascular permeability, and the migration of sarcoma cells. We also highlight the potential of exosomes as innovative diagnostic and prognostic biomarkers as well as therapeutic targets in sarcoma metastasis.

Ablative Techniques for Sarcoma Metastatic Disease: Current Role and Clinical Applications

Sarcomas are heterogenous mesenchymal neoplasms with more than 80 different histologic subtypes. Lung followed by liver and bone are the most common sites of sarcoma metastatic disease. Ablative techniques have been recently added as an additional alternative curative or palliative therapeutic tool in sarcoma metastatic disease. When compared to surgery, ablative techniques are less invasive therapies which can be performed even in non-surgical candidates and are related to decreased recovery time as well as preservation of the treated organ's long-term function. Literature data upon ablative techniques for sarcoma metastatic disease are quite heterogeneous and variable regarding the size and the number of the treated lesions and the different histologic subtypes of the original soft tissue or bone sarcoma. The present study focuses upon the current role of minimal invasive thermal ablative techniques for the management of metastatic sarcoma disease. The purpose of this review is to present the current minimally invasive ablative techniques in the treatment of metastatic soft tissue and bone sarcoma, including local control and survival rates.

PET/MR of pediatric bone tumors: what the radiologist needs to know

Integrated 2-deoxy-2-[fluorine-18]fluoro-D-glucose (18F-FDG) positron emission tomography (PET)/magnetic resonance (MR) imaging can provide "one stop" local tumor and whole-body staging in one session, thereby streamlining imaging evaluations and avoiding duplicate anesthesia in young children. 18F-FDG PET/MR scans have the benefit of lower radiation, superior soft tissue contrast, and increased patient convenience compared to 18F-FDG PET/computerized tomography scans. This article reviews the 18F-FDG PET/MR imaging technique, reporting requirements, and imaging characteristics of the most common pediatric bone tumors, including osteosarcoma, Ewing sarcoma, primary bone lymphoma, bone and bone marrow metastases, and Langerhans cell histiocytosis.

Cutaneous Metastasis of Alveolar Rhabdomyosarcoma in a Child

ABSTRACT

Rhabdomyosarcoma (RMS) is one of the most common soft tissue sarcomas in children. This lesion is classically included in the generic group of "small round blue cell tumors" along with other entities that share similar microscopic features. Although the head and neck region is a frequent site for primary tumors, cutaneous metastases of RMS involving this anatomical location are rare in the pediatric population. We report a case of a 12-year old girl previously diagnosed with a primary alveolar RMS involving the left maxillary sinus, presenting with a metastatic lesion on the skin of the left temple area. Along with a brief review of the previous case reports on the topic, we highlight the initial immunohistochemistry panel useful for diagnosing this tumor.

Molecular imaging of sarcomas with FDG PET

Sarcoma comprises a heterogenous entity of musculoskeletal malignancies arising from a mesenchymal origin. The diagnosis and management of pediatric sarcoma requires a multidisciplinary approach and the use of various imaging modalities including CT, MRI and FDG PET scans. FDG PET/CT (FDG PET), as a metabolic imaging, complements and provides superior diagnostic information as against other imaging modalities alone. Advantages of FDG PET in differentiating malignant sarcomatous lesions from benign lesions, and value in staging and restaging have been noted in several studies. The use of FDG PET in clinical management has increased over the years. The data on prognostication of outcomes or predicting responders to therapy with FDG PET in patients with sarcoma is somewhat limited. This review will focus on the pearls and pitfalls of FDG PET and role of FDG PET in initial extent of disease assessment, treatment response, and surveillance imaging pertaining to osteosarcoma, chondrosarcoma, Ewing's sarcoma, and rhabdomyosarcoma. We also discuss the limitations and unmet needs of FDG PET in the management of patients with sarcoma.

Chondrosarcoma of Ureter in an Elderly Patient: A Case Report

Chondrosarcoma is a rare type of cancer that can affect the upper urinary tract. Because of its rarity, the clinical presentation of chondrosarcoma can be similar to other urinary tract conditions, such as renal colic, hematuria, and urothelial carcinoma. The primary treatment for chondrosarcoma is the surgical removal of the tumor, and radiation or chemotherapy may be used for advanced cases. However, because of the limited number of patients with this condition, there are no established guidelines for chemotherapy, and the outcomes are unclear. In this case, we present a 71-year-old female patient who was diagnosed with ureteral chondrosarcoma. She presented with abdominal pain and hydronephrosis, and a tumor was found beneath a small stone. The patient underwent nephroureterectomy and received oral fluorouracil chemotherapy due to the advanced stage of the disease. Fortunately, the patient survived, and at the 7 months post-operative follow-up there was no evidence of recurrence. In conclusion, the chondrosarcoma of the upper urinary tract is a rare condition that can be difficult to diagnose due to its similarity to other urinary tract conditions. Treatment typically involves the surgical removal of the tumor, with radiation or chemotherapy reserved for advanced cases. However, because of the limited number of patients, there are no established guidelines for chemotherapy, and the outcomes of treatment are unclear.

An extremely rare neoplasm 'atypical spindle cell pleomorphic lipomatous tumor': a case report

Spindle cell lipoma is a rare histological variant of lipoma accounting for 1.5% of adipocytes tumors. It is composed of an admixture of mature adipocytes and fibroblast-like spindle cells in a myxoid stroma. Retroperitoneal atypical spindle cell lipomatous tumor are extremely rare only a single report in the literature reported. Herein we describe a case of a giant lipomatous tumor that was causing partial bowel obstruction. Successful excision with en block resection of the tumor, distal ureter and posterior wall of the bladder was achieved by teamwork between gastrointestinal surgeons and Urologist. The bladder defect was repaired, and left ureteric reimplantation was done. The patient made a good recovery with excellent progress. He has resumed his normal activities as a farmer.

Subcutaneous fat necrosis of the newborn: a pictorial essay of an under-recognized entity

Subcutaneous fat necrosis of the newborn is a self-limited disorder predominantly affecting full-term and post-term neonates during the first 6 weeks after birth. Subcutaneous fat necrosis can be focal or multifocal and affect one or both sides with a predilection for areas of pressure in certain anatomical areas. Subcutaneous fat necrosis of the newborn is associated with perinatal asphyxia and other neonatal and maternal risk factors. Subcutaneous fat necrosis of the newborn presents as a self-limited area of dermal edema followed by indurated subcutaneous plaques, or nontender and mobile nodules, sometimes with skin discoloration [1-3]. The diagnosis is based on the child's history and physical examination, but when in doubt, imaging is helpful. US is the imaging modality of choice to confirm the diagnosis of subcutaneous fat necrosis of the newborn because it provides the best resolution of superficial lesions, requires no sedation and lacks ionizing radiation. US can also help evaluate and characterize other pathologies affecting the superficial subcutaneous soft tissues at this age. Familiarity with subcutaneous fat necrosis of the newborn is important to make a prompt and precise diagnosis and avoid unnecessary imaging tests or invasive procedures.

Treatment modalities of ALK-positive relapsed/refractory inflammatory myofibroblastic tumor of the brain and lungs in 7-year-old girl: case-based reviews

PURPOSE

Inflammatory myofibroblastic tumor (IMT) belongs to mesenchymal neoplasm of intermediate malignancy in WHO classification. Primary CNS disease or CNS metastases (CNS-IMT) occur in minority. We describe a case of relapsed/refractory IMT of lungs with multiple brain metastases in young child who achieved long-term complete response after alectinib. This systematic review also summarizes treatment modalities and outcome of children and adolescent with CNS-IMT.

METHODS

PRISMA 2020 guideline was applied to select an article from PubMed, Scopus, and Cochrane databases without time limits. This review focused on children and adolescent 0-24 years of age with CNS-IMT or inflammatory pseudotumor (CNS-IPT). The clinical characteristics and treatment outcome were explored.

RESULTS

A total of 51 patients in 49 publications were identified. Median age of patients with CNS-IMT/IPT was 15-year-old and 60.8% were male. The most common location of tumor was cerebral cortex (54.9%). Complete resection of CNS-IMT/IPT was performed in 27 cases with 100% complete response and 18.5% recurrence. Nearly half of patients who received partial resection without adjuvant therapy experienced progressive disease, while the contrast group totally achieved partial response. Overall responses in 7 patients treating with ALK inhibitors were 57.1% durable complete response and 42.9% transient partial response.

CONCLUSION

First-line treatment of CNS-IMT/IPT is complete resection. Patients who received partial tumor removal might have benefit from adjuvant therapy. ALK inhibitors reveal a promising result in unresectable CNS-IMT/IPT. Our case has shown a success in treating relapsed and refractory CNS-IMT as well as the primary site using 2nd-generation ALK inhibitor.

Musculoskeletal Soft-tissue Masses

Evaluation of soft-tissue masses has become a common clinical practice indication for imaging with both ultrasound and MR imaging. We illustrate the ultrasonography and MR imaging appearances of soft-tissue masses based on the various categories, updates, and reclassifications of the 2020 World Health Organization classification.

Interdisciplinary Surgical Therapy of Extremity Soft-Tissue Sarcomas: A Personalized Resection and Reconstruction Algorithm

Soft-tissue sarcomas (STS) are rare, but potentially life-threatening malignancies. STS can occur anywhere in the human body with the limbs being the most common site. Referral to a specialized sarcoma center is crucial to guarantee prompt and appropriate treatment. STS treatment strategies should be discussed in an interdisciplinary tumor board to involve expertise from all available resources, including an experienced reconstructive surgeon for an optimal outcome. In many cases, extensive resection is needed to achieve R0 resection, resulting in large defects after surgery. Hence, an evaluation of whether plastic reconstruction might be required is mandatory to avoid complications due to insufficient primary wound closure. In this retrospective observational study, we present data of patients with extremity STS treated at the Sarcoma Center, University Hospital Erlangen, in 2021. We found that complications were more frequent in patients who received secondary flap reconstruction after insufficient primary wound closure compared to patients who received primary flap reconstruction. Additionally, we propose an algorithm for an interdisciplinary surgical therapy of soft-tissue sarcomas regarding resection and reconstruction and present two problematic cases to emphasize the complexity of surgical sarcoma therapy.

Malignant Solitary Fibrous Tumours of the Pleura Are Not All the Same: Analysis of Long-Term Outcomes and Evaluation of Risk Stratification Models in a Large Single-Centre Series

Introduction: Malignant solitary fibrous tumours of the pleura (mSFTP) are extremely rare diseases (<5% of all pleural neoplasms) with unpredictable behaviour. Surgery remains the standard of care for these tumours; however, estimating patient prognosis and planning follow-up remain challenging. Several risk stratification models have been proposed, but a classification with diagnostic and prognostic potential has not been well standardised yet. The aim of this study was to analyse the clinicopathological data of mSFTP to investigate their prognostic features and to compare the performance of three risk stratification models proposed in the literature. Methods: Observational retrospective cohort study on all proven cases of mSFTP surgically resected with radical intent between 2000 and 2019 in a single centre. Demographic, surgical and pathological data were examined. All patients were risk-stratified by using three prediction models: modified Demicco, De Perrot and Tapias. Overall survival (OS) and disease-free survival (DFS) were analysed. Results: There were 21 men and 13 women (median age, 67 years, range, 23-83 years). Twenty-one patients (62%) were symptomatic. The median follow-up was 111 months (range, 6-258 months). The 5-year OS and DFS were 81.2% and 77.4%, respectively. Nine patients (26.5%) experimented recurrences. At univariate analysis, the presence of necrosis (p = 0.019), nuclear atypia (p = 0.006), dimension greater than 11.5 cm (median value of our cohort) (p = 0.037) and relapse/disease progression (p = 0.001) were independent prognostic factor of worse OS. The administration of adjuvant treatment was a protective independent factor for survival (p = 0.001). Radicality of resection (p = 0.005); tumour dimension (p = 0.013), presence of necrosis (p = 0.041) and nuclear atypia (p = 0.007) and pleural pattern (p = 0.011) were independent prognostic factors of worse DFS. Analysing the three risk stratification models, the Tapias score was revealed as the best index to predict both OS (p = 0.002) and DFS (p = 0.047) in patients with mSFTP. Conclusions: Using the risk stratification model proposed by Tapias, patients with the highest risk of recurrence could be identified at the time of surgery to establish a more frequent imaging surveillance and longer follow-up. The role of adjuvant treatment in mSFTP therapy has not been established yet, but further analysis on patients with a high risk of recurrence, stratified according to risk models, along with biomolecular panels may tailor future post-surgical therapies.

Improving survival after pulmonary metastasectomy for sarcoma: analysis of prognostic factors

BACKGROUND

Metastatic sarcoma confers a grave prognosis to patients and poses a management dilemma for clinicians. Pulmonary metastasectomy is frequently performed for the recurrence of sarcomatous tumours in the lung, but the evidence-base is poor. No guidelines exist to inform clinicians on appropriate patient selection and surgical technique.

AIM

This review aims to establish and analyse the most important prognostic factors for survival post pulmonary metastasectomy for recurrent sarcoma. We summarise the key tumour, peri-operative and patient characteristics that should guide surgical management.

METHODS

A comprehensive search of the literature utilising OVID Medline and PubMed databases was conducted to identify all relevant research within the past 15 years. We evaluated all articles that specifically studied sarcoma patients (both bone and soft tissue).

CONCLUSION

Disease-free interval and tumour burden remain important prognostic factors, while tumour grade is likely not significant. VATS is a safe and viable alternative to thoracotomy without sacrificing survival outcomes. No single peri-operative characteristic provides useful prognostic information in isolation.

FISH Diagnostic Assessment of MDM2 Amplification in Liposarcoma: Potential Pitfalls and Troubleshooting Recommendations

MDM2 amplification represents the leading oncogenic pathway and diagnostic hallmark of liposarcoma, whose assessment is based on Fluorescence In Situ Hybridization (FISH) analysis. Despite its diagnostic relevance, no univocal interpretation criteria regarding FISH assessments of MDM2 amplification have been established so far, leading to several different approaches and potential diagnostic misinterpretations. This study aims to address the most common issues and proposes troubleshooting guidelines for MDM2 amplification assessments by FISH. We retrospectively retrieved 51 liposarcomas, 25 Lipomas, 5 Spindle Cell Lipoma/Pleomorphic Lipomas, and 2 Atypical Spindle Cell Lipomatous Tumors and the corresponding MDM2 FISH analysis. We observed MDM2 amplification in liposarcomas cases only (43 out of 51 cases) and identified three MDM2-amplified patterns (scattered (50% of cases), clustered (14% of cases), and mixed (36% of cases)) and two nonamplified patterns (low number of signals (82% of cases) and polysomic (18% of cases)). Based on these data and published evidence in the literature, we propose a set of criteria to guide MDM2 amplification analysis in liposarcoma. Kindled by the compelling importance of MDM2 assessments to improve diagnostic and therapeutic liposarcoma management, these suggestions could represent the first step to develop a univocal interpretation model and consensus guidelines.

Case report and literature review: Conversion surgery for initially unresectable huge retroperitoneal liposarcoma after preoperative radiotherapy

Background

Retroperitoneal liposarcoma (RPLS) is a rare malignancy that is notorious for recurrence. Surgical resection with clean margin is the current treatment of choice. However, owing to the large retroperitoneal space, RPLSs often grow to significant sizes before being diagnosed. Neoadjuvant and adjuvant therapies have potentials to improve long term treatment outcome.

Case presentation

A 55-year-old Han Chinese male presented to the general surgery department with a one-year history of abdominal fullness and a one-week history of palpable right inguinal mass. At first, he was diagnosed with incarcerated inguinal hernia. However, abdominal computer tomography (CT) and biopsy confirmed his final diagnosis to be retroperitoneal well-differentiated liposarcoma, cT2bN0M0, stage IIb. The tumor, which measured 44.5cm in maximum diameter, was too large for primary surgical resection. Neoadjuvant radiotherapy with 70 Gy in 35 fractions was delivered to the tumor, which shrunk the target volume from 6300 cc to 4800 cc, as observed in the middle of the radiotherapy course. The right testicular mass also received 70Gy/35Fx. Conversion surgery was performed after radiotherapy. Unfortunately, due to residual tumor, adjuvant chemotherapy consisting of AIM (ifosfamide, Mesna, and doxorubicin) and MAID (Mesna, doxorubincin, ifosfamide, and dacarbazine) regimens were administered sequentially. Afterward, debulking surgery was conducted, plus another 18 cycles of ifosfamide monotherapy when residual tumor was still seen on CT. Since the completion of ifosfamide chemotherapy, the patient has been cancer free with no evidence of tumor recurrence for more than 26 months.

Conclusion

Despite conflicting evidence in the literature, our case supports the use of high dose neoadjuvant radiotherapy and adjuvant chemotherapy in treating large, unresectable RPLSs. It also highlights the importance of using individualized, multidisciplinary approach in achieving cure for large, unresectable rare tumors.

Giant Cell Tumor of Lumbar Vertebrae on MR and 18F- FDG PET/CT: A Case Report and Literature Review

Teaching Point: Giant cell tumor of bone may show a moderate to high FDG uptake, and attention should be paid to differentiate from malignant tumors.

Soft-Tissue Sarcomas in Adults in Ecuador in the Period 2010-2020

Background

Soft-tissue sarcomas (STSs) are rare tumors; they represent 1% of all tumors in adults. There are new diagnostic techniques to differentiate tumor types, and surgery continues to be the most important treatment for STS.

Methods

This cross-sectional study analyzed the morbidity and mortality caused by STS in adults between 2010 and 2020 using national databases.

Results

A total of 8,393 patients hospitalized due to STS were reported. The total number of deaths in Ecuador due to STS was 7,088 over the last decade, the provinces of Pichincha and Guayas registered the highest number of cases, and the mortality rate was 1.2 to 2.0 per 100,000 people. It is noteworthy that the lowest point of registered cases was in 2012.

Conclusion

Soft-tissue sarcomas are rare tumors in Ecuador. The morbidity and mortality caused by these tumors have not changed in the last decade. National studies are needed to determine the prevalence of this illness and study intervention to lower mortality.

Primary alveolar rhabdomyosarcoma of the breast skin: a case report and literature review

Alveolar rhabdomyosarcoma is one of the four subtypes of rhabdomyosarcoma identified by the World Health Organization. This type of malignant neoplasms more often affects deep soft tissues of extremities and occurs in young ages, regardless of gender. According to the medical literature, no more than 45 cases of the development of primary cutaneous rhabdomyosarcoma have been reported in the world. In this report, we describe a clinical case of a 40-year-old woman with primary localization of alveolar radbomyosarcoma in the skin of the mammary gland.

Splicing-Disrupting Mutations in Inherited Predisposition to Solid Pediatric Cancer

The prevalence of hereditary cancer in children was estimated to be very low until recent studies suggested that at least 10% of pediatric cancer patients carry a germline mutation in a cancer predisposition gene. A significant proportion of pathogenic variants associated with an increased risk of hereditary cancer are variants affecting splicing. RNA splicing is an essential process involved in different cellular processes such as proliferation, survival, and differentiation, and alterations in this pathway have been implicated in many human cancers. Hereditary cancer genes are highly susceptible to splicing mutations, and among them there are several genes that may contribute to pediatric solid tumors when mutated in the germline. In this review, we have focused on the analysis of germline splicing-disrupting mutations found in pediatric solid tumors, as the discovery of pathogenic splice variants in pediatric cancer is a growing field for the development of personalized therapies. Therapies developed to correct aberrant splicing in cancer are also discussed as well as the options to improve the diagnostic yield based on the increase in the knowledge in splicing.

The mitotic regulator polo-like kinase 1 as a potential therapeutic target for c-Myc-overexpressing canine osteosarcomas

Osteosarcoma is the most common primary malignant bone tumour in dogs, characterized by a locally aggressive and highly metastatic behaviour. Despite the current standards of care, most dogs succumb to the disease, indicating the need for novel treatment strategies. Polo-like kinase 1 (PLK1) is dysregulated in a variety of human cancer types, including osteosarcoma, and induces c-Myc accumulation. The crosstalk between the two molecules coordinates cell proliferation, differentiation, self-renewal and apoptosis. Therefore, PLK1 has recently emerged as a potential therapeutic target, mainly in tumours overexpressing c-Myc. BI 2536 is a selective PLK1 inhibitor promoting mitotic arrest and apoptosis in a variety of cancer cells. This research aimed at evaluating PLK1 and c-Myc protein expression in 53 appendicular canine osteosarcoma (cOSA) samples and the in vitro effects of BI 2536 on a c-Myc and PLK1-overexpressing cOSA cell line (D17). PLK1 and c-Myc expression in cOSA samples showed no correlation with clinicopathological data. However, c-Myc overexpression was associated with a significantly reduced overall survival (p = .003). Western Blot and RT-qPCR assays revealed that D17 expressed high protein and transcript levels of both PLK1 and MYC. When treated with BI 2536 (range 2.5-15 nM) for 24 h, D17 showed a substantial decrease in cell growth, inducing apoptosis and G₂ /M cell cycle arrest. Interestingly, under BI 2536 treatment, D17 showed decreased c-Myc protein levels. Consistent with human OSA, these preliminary data outline the prognostic value of c-Myc expression in cOSA and highlight the potential role of PLK1 as an antiproliferative therapeutic target for tumours overexpressing c-Myc.

Increase of atypical fibroxanthoma and pleomorphic dermal sarcoma: a retrospective analysis of four German skin cancer centers

BACKGROUND AND OBJECTIVES

In recent years, considerable insight has been gained into the pathogenesis, diagnosis and treatment of cutaneous sarcomas, including atypical fibroxanthoma (AFX) and pleomorphic dermal sarcoma (PDS). Both entities have shown increasing incidence rates in the last decade. This study was initiated to evaluate how these new insights impact the number of diagnoses of AFX/PDS compared to other cutaneous sarcoma entities.

PATIENTS AND METHODS

In a retrospective study of four German skin cancer centers, all histopathological reports of cutaneous sarcomas (AFX, PDS, dermatofibrosarcoma protuberans, cutaneous leiomyosarcoma, angiosarcoma, and Kaposi sarcoma) confirmed by board-certified dermatopathologists were analyzed during a time-period of seven years (2013-2019). Additionally, utilization of immunohistochemical markers (including pan-cytokeratin, S100, desmin, CD34, CD10, procollagen-1, CD99, CD14, and CD68) as an adjunct to diagnose AFX/PDS was recorded.

RESULTS

Overall, 255 cutaneous sarcomas were included in the present study. The diagnosis of a cutaneous sarcoma has consequently risen from 2013 to 2019 (from 16 to 52 annual cases). The results of AFX/PDS revealed 4.6 times more diagnoses in 2019 than in 2013. Atypical fibroxanthoma represented the most common subtype, displaying 49.3 % of all diagnosed cutaneous sarcomas. Additionally, the increase of AFX/PDS was linked to the use of immunohistochemistry, with specific immunohistochemical markers used in 57.1 % of cases in 2013 compared to 100 % in 2019.

CONCLUSIONS

This retrospective study of four German skin cancer centers demonstrates a substantial rise of AFX/PDS, possibly due to recently established diagnostic and terminology standards. This rise is probably linked to increased utilization of specific immunohistochemical markers. Atypical fibroxanthoma/PDS may be more common than previously thought and seems to represent the most frequent cutaneous sarcoma subtype.

Zunahme des atypischen Fibroxanthoms und pleomorphen dermalen Sarkoms: eine retrospektive Analyse vier deutscher Hauttumorzentren

HINTERGRUND UND ZIELE

In den letzten Jahren konnten umfassende Erkenntnisse über die Pathogenese, Diagnostik und Behandlung von kutanen Sarkomen, insbesondere des atypischen Fibroxanthoms (AFX) und pleomorphen dermalen Sarkoms (PDS) gesammelt werden. Beide Entitäten zeigten innerhalb der letzten Dekade steigende Inzidenzraten. Die vorliegende Studie diente der Untersuchung, welchen Einfluss die neuen Erkenntnisse auf die Fallzahlen von AFX/PDS im Vergleich zu anderen Sarkom-Entitäten haben.

PATIENTEN UND METHODIK

Diese retrospektive Studie wurde an vier deutschen Hauttumorzentren durchgeführt und alle von zertifizierten Dermatopathologen bestätigten histopathologischen Befunde von kutanen Sarkomen (AFX, PDS, Dermatofibrosarcoma protuberans, kutanes Leiomyosarkom, Angiosarkom und Kaposi-Sarkom) in einem Zeitraum von sieben Jahren (2013-2019) evaluiert. Zusätzlich wurde der Einsatz von immunhistochemischen Markern als diagnostische Hilfe (Panzytokeratin, S100, Desmin, CD34, CD10, Prokollagen-1, CD99, CD14 und CD68) erfasst.

ERGEBNISSE

Insgesamt konnten 255 kutane Sarkome in die vorliegende Studie eingeschlossen werden. Die Zahl der kutanen Sarkome nahm kontinuierlich von 2013 bis 2019 zu (von 16 auf 52 Fälle im Jahr). Die Diagnose eines AFX/PDS konnte in 2019 4,6-mal häufiger als in 2013 gestellt werden. Das AFX stellte mit 49,3 % aller kutanen Sarkome den häufigsten Sarkom-Subtypen dar. Zusätzlich war der Anstieg von AFX/PDS mit dem Einsatz von Immunhistochemie assoziiert. Der Einsatz von spezifischen Immunhistochemischen Markern stieg von 57,1 % im Jahr 2013 auf 100 % in 2019.

SCHLUSSFOLGERUNGEN

Diese retrospektive Studie von vier deutschen Hauttumorzentren demonstriert eine substanzielle Zunahme von AFX/PDS, wahrscheinlich infolge kürzlich etablierter beziehungsweise verbesserter diagnostischer und terminologischer Standards. Dieser Anstieg ist vermutlich mit dem vermehrten Einsatz von bestimmten immunhistochemischen Markern assoziiert. AFX/PDS treten wahrscheinlich häufiger auf als bisher vermutet und repräsentieren möglicherweise den häufigsten kutanen Sarkom-Subtyp.

Baseline Characteristics, Prognostic Factors, and Treatment Outcomes for Adult Patients With Rhabdomyosarcoma (RMS)

BACKGROUND

Rhabdomyosarcoma (RMS) is the most common soft tissue sarcoma of childhood, while in adults it is one of the rarer tumors. Its prognosis is better in children with current treatment modalities; however, it carries poorer prognosis in adults. Recent data on adult RMS is scarce from our part of world. We report outcomes of adult patients with RMS, and with 40 patients; it is the first study to publish such a large data from Pakistan.

METHODS

This was a retrospective study that included 64 adult patients aged 18 years and older. After data extraction and scrutiny, a total of 40 patients were segregated with diagnosis of RMS of various varieties who were treated and followed up subsequently. International Business Machines (IBM) Statistical Package for Social Sciences (SPSS), version 26 (IBM Corp., Armonk, NY) was used to evaluate all of the gathered data.

RESULTS

Embryonal RMS (ERMS) was the most common subtype. Factors favoring better overall survival (OS) at 5 years were absence of nodal and distal metastases, treatment with surgery, margin negative resection, and absence of residual disease on postoperative imaging. Adjuvant radiation therapy (XRT) for positive resection margins as well as for residual disease on postoperative imaging also favored better OS at 5 years. Chemotherapy did impart a trend towards better OS; however, it was not significant. Histopathologic subtype and tumor size did not have any significant impact on outcomes. Median progression free survival (PFS) was 11 months and median OS was 15 months.

CONCLUSIONS

Adult RMS is a rare disease entity with widely heterogeneous clinical picture and poorer outcomes as compared to the disease of childhood and adolescence. Further prospective studies with larger sample size are required to establish role of patient, disease, and treatment-related factors affecting outcomes in our population.

Implementation of Whole-Genome and Transcriptome Sequencing Into Clinical Cancer Care

PURPOSE

The combination of whole-genome and transcriptome sequencing (WGTS) is expected to transform diagnosis and treatment for patients with cancer. WGTS is a comprehensive precision diagnostic test that is starting to replace the standard of care for oncology molecular testing in health care systems around the world; however, the implementation and widescale adoption of this best-in-class testing is lacking.

METHODS

Here, we address the barriers in integrating WGTS for cancer diagnostics and treatment selection and answer questions regarding utility in different cancer types, cost-effectiveness and affordability, and other practical considerations for WGTS implementation.

RESULTS

We review the current studies implementing WGTS in health care systems and provide a synopsis of the clinical evidence and insights into practical considerations for WGTS implementation. We reflect on regulatory, costs, reimbursement, and incidental findings aspects of this test.

CONCLUSION

WGTS is an appropriate comprehensive clinical test for many tumor types and can replace multiple, cascade testing approaches currently performed. Decreasing sequencing cost, increasing number of clinically relevant aberrations and discovery of more complex biomarkers of treatment response, should pave the way for health care systems and laboratories in implementing WGTS into clinical practice, to transform diagnosis and treatment for patients with cancer.

Progress on Denosumab Use in Giant Cell Tumor of Bone: Dose and Duration of Therapy

Giant cell tumor of bone (GCTB) is an aggressive non-cancerous bone tumor associated with risks of sarcoma and metastasis. Once malignancy occurs, the prognosis is generally poor. Surgery remains the main treatment for GCTB. Multidisciplinary management is a feasible option for patients wherein surgical resection is not an option or for those with serious surgery-related complications. Denosumab is an anti-nuclear factor kappa B ligand approved for the treatment of postmenopausal women with osteoporosis, bone metastases, and advanced or inoperable GCTB. However, the guidelines for treating GCTB are unclear; its short-term efficacy and safety in inoperable patients have been demonstrated. Lengthier therapies (high cumulative doses) or pre-operative adjuvant therapy may be associated with severe complications and high local recurrence rates. Short-term administration helps attain satisfactory local control and functionality. As a result, lately, the impact of different doses and lengths of treatment on the efficacy of denosumab in GCTB treatment, the incidence of complications, and recurrence rates have gained attention. The efficacy and safety of denosumab against GCTB, its impact on imaging assessment, related complications, and recurrence of GCTB were previously reviewed. For further research direction, this paper reviews the progress of studies evaluating the impact of the dose and duration of denosumab therapy for GCTB.

Laparoscopic treatment of inflammatory myofibroblastic tumor in liver: A case report

BACKGROUND

Inflammatory myofibroblastic tumor in the liver (IMTL) is a rare borderline mesenchymal tumor. Neither clinical symptoms nor laboratory tests have absolute specificity for the diagnosis of IMTL, and imaging also lacks obvious specificity. Although there are sporadic reports of recurrence after surgical treatment, surgical resection is the mainstay of treatment.

CASE SUMMARY

A 29-year-old man complained of general weakness, slight discomfort in the upper abdomen, with a history of upper respiratory tract infection for 1 wk before admission. Plain and enhanced upper abdominal magnetic resonance imaging showed a mass in liver segments II and III (48 mm × 53 mm). He was treated by laparoscopic left lateral segmentectomy. Postoperative pathological examination with hematoxylin and eosin staining suggested that the mass in liver segments II and III was IMTL. During 21 mo postoperative follow-up, no obvious residual or recurrent lesions were observed.

CONCLUSION

There is a risk of malignant degeneration in IMTL. The principal choice of treatment is laparoscopic left lateral segmentectomy.

Myxoid pleomorphic liposarcoma in the teres minor muscle: A case report

RATIONALE

Myxoid pleomorphic liposarcoma (MPL) is a rare aggressive adipocytic tumor that mainly presents in children and adolescents. It is most frequently observed in the mediastinum and rarely in the head and neck, perineal region, or back. Herein, we report the first published case of MPL of the teres minor muscle.

PATIENT CONCERNS

A 24-years-old woman presented with a painless palpable mass in her right shoulder.

DIAGNOSES

Magnetic resonance imaging identified a 9.0 × 7.0 × 4.0 cm mass suspected to be a sarcoma in the teres minor muscle. Positron emission tomography/computed tomography revealed no evidence of distant metastasis. Histopathological examination revealed the mass to be an MPL, which was assigned a histologic grade of 3 according to the French Federation of Cancer Centers Sarcoma Group system. No tumor cells were observed along the resected margins.

INTERVENTIONS

Under general anesthesia, the right teres minor muscle containing the mass was excised en bloc and frozen biopsy confirmed that the tumor cells did not invade the surrounding tissues.

OUTCOMES

The patient underwent radiotherapy and was followed up for 6 months without complications.

LESSONS

Although MPL in the teres minor muscle is rare, it should be considered in the differential diagnosis in patients with a mass in the teres minor muscle due to its poor prognosis.

Personalized Surgical Planning for Soft Tissue Sarcoma of the Popliteal Fossa with a Novel 3D Imaging Technique

OBJECTIVE

Soft tissue sarcomas (STSs) arising from the popliteal fossa pose surgical challenges due to their proximity to critical neurovascular structures. This study aimed to investigate whether a novel 3D imaging technique highlighting these key anatomical structures could facilitate preoperative planning and improve surgical outcomes in STS.

METHODS

This was a prospective, observational, pilot study. Between November 2019 and December 2020, 27 patients with STS of the popliteal fossa undergoing limb-sparing procedures were enrolled and assigned to either a control or intervention group. Control patients underwent traditional preoperative planning with separate computed tomography angiography, magnetic resonance imaging, and magnetic resonance hydrography. In the intervention group, 3D images were generated from these images, the tumor and skeletomuscular and neurovascular structures were revealed in three dimensions, and this was visualized on the surgeon's smartphone or computer. Primary endpoints were surgical margins and complications. Secondary endpoints included operative time, blood loss, serum C-reactive protein and interleukin-6, length of in-hospital stay, and limb function. Comparisons between groups were made using independent-sample t-tests for continuous data and the Mann-Whitney U and Fisher's exact tests for categorical data.

RESULTS

There was a lower but not significantly different inadvertent positive margin rate (1/15 vs. 3/12, P = 0.294), significantly shorter hospital stay (P = 0.049), and less numbers ≥75th percentile of operative time (P = 0.037) and blood loss (P = 0.024) in the intervention group. Differences in surgical complications, operative time, blood loss, C-reactive protein and interleukin-6 levels on the second postoperative day, and limb functional scores were statistically insignificant.

CONCLUSIONS

The novel 3D imaging technique facilitates complex preoperative planning and limb-salvage surgical procedures for patients with STS of the popliteal fossa, and this may affect how surgical planning is performed in the future.

Lipoma with osteocartilaginous metaplasia in infrapatellar fat pad: A case report and review of literature

RATIONALE

Lipomas are tumors composed of mature adipocytes, originating from the mesoderm, and are the most common soft tissue tumor. According to the World Health Organization classification of human soft tissue and bone tumors, there are 14 types of benign tumors, including mature adipose tissue. Osteolipoma is known as the rarest subtype of lipoma.

PATIENT CONCERNS

A 63-year-old female presented to our hospital for the evaluation and treatment of a palpable mass with pain in the right knee.

DIAGNOSIS

The diagnosis was confirmed as lipoma with osteocartilaginous metaplasia.

INTERVENTIONS

Surgical removal of the tumor was performed.

OUTCOMES

The main symptoms improved immediately after the surgery and recovered without any complications or recurrence until 2 years after surgery.

LESSONS

Lipoma with osteochondral degeneration is a rare variant of lipoma and it is important to differentiate it from other malignant tumors. Pathological confirmation should be performed after marginal resection of the mass.

Low-grade fibromyxoid sarcoma of the vulva presenting as a cystic mass: A case report and review of literature

INTRODUCTION

Low-grade fibromyxoid sarcoma (LGFMS) is a tumor with a propensity for late recurrence which is rarely described in the vulva.

CASE PRESENTATION

A 22-year-old woman presented with a growing right vulvar cystic mass that had been present for 2 months. She underwent surgical wide excision. The final pathologic diagnosis revealed LGFMS of the vulva and a right radical hemivulvectomy with negative margins was performed.

RESULTS

The patient has not experienced a local or metastatic recurrence after 2-years follow- up.

CONCLUSIONS

Despite being rare, LGFMS of the vulva should be taken into account when making a diagnosis of vulvar lesions. Definite diagnosis is based on pathological examination. MUC4 positivity is characteristically expressed. To prevent future recurrences, radical excision is necessary.

Apatinib Functioned as Tumor Suppressor of Synovial Sarcoma through Regulating miR-34a-5p/HOXA13 Axis

Objective

Synovial sarcoma is a rare malignant tumor. The role of apatinib in synovial sarcoma remains unclear. In this study, we aimed to determine the biological functions and the potential molecular mechanism of action of apatinib in synovial sarcoma.

Methods

SW982 cells were stimulated with apatinib. The relative expression of the genes was determined by performing qPCR. Protein levels were evaluated by western blot and immunohistochemistry assays. Proliferation, apoptosis, migration, and invasion of SW982 cells were determined by the CCK-8 assay, clone formation assay, flow cytometry, wound healing, and the transwell assay, respectively. Additionally, SW982 cells were injected into mice to induce synovial sarcoma.

Results

Apatinib decreased the proliferation, migration, and invasion but increased the apoptosis of SW982 cells. Apatinib repressed tumor growth in vivo and elevated miR-34a-5p in SW982 cells. The inhibition of miR-34a-5p repressed the reduction of proliferation, migration, and invasion and also the elevation of apoptosis in apatinib-treated SW982 cells. The luciferase activity decreased after cotransfection of the miR-34a-5p mimic and the wild-type HOXA13 vector. Additionally, an increase in miR-34a-5p repressed the levels of HOXA13 mRNA and protein. Moreover, HOXA13 reversed these patterns caused by the inhibition of miR-34a-5p in apatinib-treated SW982 cells.

Conclusion

Apatinib elevated miR-34a-5p and reduced HOXA13, leading to a significant decrease in proliferation, migration, and invasion, along with an enhancement of apoptosis in SW982 cells. Apatinib suppressed tumorigenesis and tumor growth in SW982 cells in vivo.

B7-H3-targeting Fc-optimized antibody for induction of NK cell reactivity against sarcoma

Natural killer (NK) cells largely contribute to antibody-dependent cellular cytotoxicity (ADCC), a central factor for success of monoclonal antibodies (mAbs) treatment of cancer. The B7 family member B7-H3 (CD276) recently receives intense interest as a novel promising target antigen for immunotherapy. B7-H3 is highly expressed in many tumor entities, whereas expression on healthy tissues is rather limited. We here studied expression of B7-H3 in sarcoma, and found substantial levels to be expressed in various bone and soft-tissue sarcoma subtypes. To date, only few immunotherapeutic options for treatment of sarcomas that are limited to a minority of patients are available. We here used a B7-H3 mAb to generate chimeric mAbs containing either a wildtype Fc-part (8H8_WT) or a variant Fc part with amino-acid substitutions (S239D/I332E) to increase affinity for CD16 expressing NK cells (8H8_SDIE). In comparative studies we found that 8H8_SDIE triggers profound NK cell functions such as activation, degranulation, secretion of IFNγ and release of NK effector molecules, resulting in potent lysis of different sarcoma cells and primary sarcoma cells derived from patients. Our findings emphasize the potential of 8H8_SDIE as novel compound for treatment of sarcomas, particularly since B7-H3 is expressed in bone and soft-tissue sarcoma independent of their subtype.

An extremely scarce incidence of primary Undifferentiated Pleomorphic Sarcoma of the Scalp of a 52-year-old female - A Case Report

Introduction and importance

Sarcomas are malignant mesenchymal-cell tumors that comprise 1 % of all adult tumors. Undifferentiated Pleomorphic Sarcoma comprises a vastly rare subtype. It mostly occurs in males in their 6th decade of life. However, their exact incidence remains poorly demarcated, especially those occurring in the scalp. Since they lack any disease-specific presentations, we should maintain high clinical suspicion when presented with similar cases.

Case presentation

Herein, we demonstrate the clinical case of a 52-year-old Middle Eastern female, who presented to the outpatient clinic complaining of a one-year history of progressively growing protuberance in her right side of the scalp. It was painful and rapidly increased in size. Presurgical radiological assessment suspected a cystic formation. Utter resection of the mass was achieved, and histopathological analysis diagnosed it as a primary Undifferentiated Pleomorphic Sarcoma.

Clinical discussion

Meticulous surgical resection was the cornerstone treatment of our patient. Radiological imaging in addition to clinical suspicion was utilized for preoperative assessment. This patient has had a successful post-surgical recovery. She has been surveilled for 6 months so far with no evidence of tumor recurrence, metastasis, or clinical complications.

Conclusion

It is especially rare to see a primary Undifferentiated Pleomorphic Sarcoma in any patient population. It's even rarer that it occurs in such a patient demographic. Hence, it's vital that we document cases of this rare malignancy because that would lead the way in conducting informative clinical studies which enable physicians to select the proper treatment modality.

•

Sarcomas are malignant mesenchymal-cell tumors that comprise 1 % of all adult tumors.

•

Undifferentiated Pleomorphic Sarcoma comprises a rare subtype. It mostly occurs in males in their 6th decade.

•

UPS showed higher tendencies to occur in males rather than females and favored the White rather than African race.

•

To establish a final diagnosis relies on competent histopathological and immunohistochemical analysis.

•

The ideal management of UPS occurring in the head and neck is utter surgical resection with free margins of 2 cm.

Head‑to‑head assessment of [68Ga]Ga-DOTA-FAPI-04 PET/CT vs [18F]FDG PET/CT in fibroblastic tumors

OBJECTIVES

We aimed to evaluate [⁶⁸Ga]Ga-DOTA-FAPI-04 versus [¹⁸F]FDG PET/CT in the application of fibroblastic tumors.

METHODS

Twenty participants with 6 subtypes of fibroblastic tumors prospectively underwent ¹⁸F-FDG and [⁶⁸Ga]Ga-DOTA-FAPI-04 PET/CT examinations to evaluate the lesions. PET/CT findings were confirmed by surgical pathology of fifteen participants, puncture biopsy of two participants, or imaging follow-up of three participants. Two independent sample t tests were used to compare the uptake of [¹⁸F]FDG vs [⁶⁸Ga]Ga-DOTA-FAPI-04 in primary, recurrent and metastatic lesions. One-way ANOVA was used to compare the uptake of [¹⁸F]FDG or [⁶⁸Ga]Ga-DOTA-FAPI-04 among primary, recurrent, and metastatic lesions. The uptake of [⁶⁸Ga]Ga-DOTA-FAPI-04 vs [¹⁸F]FDG in different histopathological lesions was compared by two independent sample t tests.

RESULTS

Twenty participants were confirmed to have 38 lesions. Although there was no significant difference in the detection of lesions between [⁶⁸Ga]Ga-DOTA-FAPI-04 and [¹⁸F]FDG PET/CT (38 vs 36, p = 0.493), the uptake of [⁶⁸Ga]Ga-DOTA-FAPI-04 in lesions was significantly higher than that of [¹⁸F]FDG (p < 0.001), including primary (p < 0.001), recurrent (p = 0.018) and metastatic (p < 0.001) lesions. The SUVmax of [⁶⁸Ga]Ga-DOTA-FAPI-04 in primary and recurrent lesions was higher than that in metastasis (p = 0.034 and p = 0.015, respectively). The SUVmax of [⁶⁸Ga]Ga-DOTA-FAPI-04 in primary and recurrent malignant lesions was significantly higher than that of the intermediate (p < 0.001). The SUVmax of [⁶⁸Ga]Ga-DOTA-FAPI-04 in one participant of recurrent SFT with 5 lesions was significantly lower after treatment than before treatment (p = 0.016).

CONCLUSIONS

[⁶⁸Ga]Ga-DOTA-FAPI-04 outperformed [¹⁸F]FDG PET/CT in displaying the primary, recurrent and metastatic lesions of fibroblastic tumors.

The Immune Contexture of Liposarcoma and Its Clinical Implications

Liposarcomas (LPS) are the most frequent malignancies in the soft tissue sarcoma family and consist of five distinctive histological subtypes, termed well-differentiated LPS, dedifferentiated LPS (DDLPS), myxoid LPS (MLPS), pleomorphic LPS, and myxoid pleomorphic LPS. They display variations in genetic alterations, clinical behavior, and prognostic course. While accumulating evidence implicates a crucial role of the tumor immune contexture in shaping the response to anticancer treatments, the immunological landscape of LPS is highly variable across different subtypes. Thus, DDLPS is characterized by a higher abundance of infiltrating T cells, yet the opposite was reported for MLPS. Interestingly, a recent study indicated that the frequency of pre-existing T cells in soft tissue sarcomas has a predictive value for immune checkpoint inhibitor (CPI) therapy. Additionally, B cells and tertiary lymphoid structures were identified as potential biomarkers for the clinical outcome of LPS patients and response to CPI therapy. Furthermore, it was demonstrated that macrophages, predominantly of M2 polarization, are frequently associated with poor prognosis. An improved understanding of the complex LPS immune contexture enables the design and refinement of novel immunotherapeutic approaches. Here, we summarize recent studies focusing on the clinicopathological, genetic, and immunological determinants of LPS.

Locally advanced cervical rhabdomyosarcoma in adults: A case report

BACKGROUND

Rhabdomyosarcoma is a soft tissue tumor of primitive mesenchymal cells origin, occurring predominantly in children and adolescents, but extremely rare in adults and the data regarding its treatment are sparse. Here, we would like to share our experience in the treatment of a locally advanced primary embryonal rhabdomyosarcoma of cervix in a 39-year-old female.

CASE SUMMARY

The patient was admitted with symptoms of intermenstrual bleeding and postcoital bleeding for six months. Physical examination revealed a friable, polyp-like mass (5 cm × 5 cm) in her cervix protruding into the vagina, while the uterus was mobile and normal-sized. Colposcopy-directed biopsy was performed, and a pathological diagnosis of embryonal rhabdomyosarcoma was made. Magnetic resonance imaging of the pelvis showed that the cervical volume was significantly increased, with a hypointense and hyperintense soft tissue mass on the right side, invading the cervical stroma; the mass was 5 cm × 5 cm with a clear boundary and confined to the cervix; there were no obvious findings indicating tumor invasion in the vaginal wall, parametrium, or pelvic wall; no enlarged lymph nodes were observed in the pelvic cavity. Based on our findings, the tumor was classified as stage IA according to the intergroup rhabdomyosarcoma studies criteria and IB3 stage according to The International Federation of Gynecology and Obstetrics 2018. The patient underwent two courses of neoadjuvant chemotherapy and a partial remission was achieved. Subsequently, she underwent laparoscopic radical hysterectomy, bilateral salpingo-oophrectomy and pelvic lymph node dissection and there were no risk factors revealed by postoperative pathological examination. Adjuvant chemotherapy was performed after surgery. The patient was disease-free until the last follow-up, 49 mo after completing the entire treatment.

CONCLUSION

Our experience suggests that neoadjuvant vincristine, dactinomycin, and cyclophosphamide chemotherapy followed by radical surgery and adjuvant chemotherapy might be reasonable therapeutic option for bulky cervical rhabdomyosarcoma in adults without fertility desire. Since large-scale studies on such rare conditions are rather impossible, further case reports and systematic reviews could help optimize the treatment of primary, bulky cervical rhabdomyosarcoma in adults.

Pediatric rhabdomyosarcoma incidence and survival in the United States: An assessment of 5656 cases, 2001-2017

BACKGROUND

While rhabdomyosarcoma (RMS) is the most common soft tissue sarcoma in children and adolescents, past epidemiology studies of this malignancy used data that covered <30% of the US population. Therefore, we evaluated RMS incidence using data from U.S. Cancer Statistics (USCS) and survival trends using the National Program of Cancer Registries (NPCR), which covers 100% and 94% of the U.S. population, respectively.

METHODS

Incidence and survival were assessed for pediatric patients diagnosed with RMS during 2003-2017 and 2001-2016, respectively. Both demographic and clinical variables were evaluated. Age-adjusted incidence rates, average annual percent change (AAPC), and 5-year relative survival (RS) were calculated, all with corresponding 95% confidence intervals (CIs). Cox regression models were used to evaluate the impact of demographic and clinical variables on survival.

RESULTS

We identified 5656 primary RMS cases in USCS during 2003-2017. The age-adjusted incidence rate was 4.58 per 1 million (95% CI: 4.46-4.70) with an AAPC of 0.3% (95% CI: -0.7 to 1.2%). In NPCR, 5-year RS for all cases was 68.0% (95% CI: 66.6-69.3%). In multivariable analyses, non-Hispanic (NH) Black cases had worse survival compared with NH White cases (hazard ratio [HR] = 1.16, 95% CI: 1.01-1.33).

CONCLUSION

The incidence and survival rates were stable in the largest and most comprehensive population-based analysis for pediatric RMS cases in the U.S. Additionally, we observed a survival disparity among NH Black cases. Findings from this study could inform interventions to address disparities, risk stratification strategies, and clinical trial design.

Molecular profile of head and neck rhabdomyosarcomas: A systematic review and meta-analysis

OBJECTIVE

This systematic review aimed to identify the molecular alterations of head and neck rhabdomyosarcomas (HNRMS) and their prognostic values.

STUDY DESIGN

An electronic search was performed using PubMed, Embase, Scopus, and Web of Science with a designed search strategy. Inclusion criteria comprised cases of primary HNRMS with an established histopathological diagnosis and molecular analysis. Forty-nine studies were included and were appraised for methodological quality using the Joanna Briggs Institute Critical Appraisal tools. Five studies were selected for meta-analysis.

RESULTS

HNRMS predominantly affects pediatric patients (44.4%), and the parameningeal region (57.7%) is the most common location. The alveolar variant (43.2%) predominates over the embryonal and spindle cell/sclerosing types, followed by the epithelioid and pleomorphic variants. PAX-FOXO1 fusion was observed in 103 cases of alveolar RMS (79.8%). MYOD1 mutation was found in 39 cases of sclerosing/spindle cell RMS (53.4%). FUS/EWSR1-TFCP2 gene fusions were identified in 21 cases of RMS with epithelioid and spindle cell morphologies (95.5%). The 5-year overall survival rate of patients was 61.3%, and MYOD1 mutation correlated with significantly higher mortality.

CONCLUSION

The genotypic profile of histologic variants of HNRMS is widely variable, and MYOD1 mutation could be a potential prognostic factor, but more studies are required to establish this.

Malignant melanotic nerve sheath tumors in the spinal canal of psammomatous and non-psammomatous type: Two case reports

BACKGROUND

A malignant melanotic nerve sheath tumor (MMNST), previously known as a melanotic schwannoma, is a rare variant of a peripheral nerve sheath tumor composed of Schwann cells with melanotic differentiation. Only a few reports of spinal MMNST have been reported.

CASE SUMMARY

In the first case, a 58-year-old woman presented with a history of low back pain and paresthesia. Magnetic resonance imaging (MRI) and computed tomography (CT) of the lumbar spine revealed an intradural extramedullary mass lesion with amorphous linear calcification. Complete tumor resection was performed and histological examination revealed a psammomatous melanotic schwannoma. In the second case, a 72-year-old man presented with low back pain and paresthesia. MRI of the thoracolumbar spine revealed an intramedullary mass lesion at the T11 vertebral body level. The mass lesion was hypointense on T2WI and hyperintense on T1WI. Tumor resection was performed and the histologic result was melanotic schwannoma.

CONCLUSION

MMNST should be considered in the differential diagnosis when calcification or melanin is seen in an intradural spinal tumor.