Alveolar soft part sarcoma (ASPS) is a rare malignant tumor that manifests as a slow-growing soft tissue mass and frequently presents with distant metastasis. The prognosis is variable, and complete remission of metastatic disease has rarely been reported. Our patient was diagnosed with metastatic ASPS at the age of 17, with a primary forearm lesion and metastasis to the lungs. She underwent surgical resection of her forearm mass, followed by adjuvant chemotherapy and radiation to target the lung metastasis. Over the next decade, she had a complicated course of treatment. Her disease continued to slowly progress despite treatment with sunitinib, pazopanib, and a combination of docetaxel and gemcitabine. We eventually treated her with immune checkpoint inhibitors (ICIs). Pembrolizumab, initially in combination with bevacizumab and later as monotherapy, resulted in significant tumor shrinkage, especially in the pulmonary lesions, within the first three months. Subsequent imaging reported complete remission within 15 months and no disease recurrence at her three-year follow-up. Our case highlights one of the very few reported cases of complete remission achieved in metastatic ASPS after treatment with ICIs. ICIs could offer hope for disease remission in advanced ASPS, a rare malignancy that has proven difficult to treat successfully in the past. More studies need to be conducted to further evaluate the efficacy and any associated predictors of successful treatment.

BACKGROUND: Primary pulmonary myxoid sarcoma (PPMS) is a rare, low-grade malignant tumor, constituting approximately 0.2% of all lung tumors. Despite its rarity, PPMS possesses distinctive histological features and molecular alterations, notably the presence of EWSR1-CREB1 gene fusion. However, its precise tissue origin remains elusive, posing challenges in clinical diagnosis.
UNASSIGNED: A 20-year-old male patient underwent a routine physical examination 6 months prior, revealing a pulmonary mass. Following surgical excision, microscopic evaluation unveiled predominantly short spindle-shaped tumor cells organized in a fascicular, beam-like, or reticular pattern. The stromal matrix exhibited abundant mucin, accompanied by lymphocytic and plasma cell infiltration, with Russell bodies evident in focal areas. Immunophenotypic profiling revealed positive expression of vimentin and epithelial membrane antigen in tumor cells, whereas smooth muscle actin and S-100, among others, were negative. Ki-67 proliferation index was approximately 5%. Subsequent second-generation sequencing identified the characteristic EWSR1-CREB1 gene fusion. The definitive pathological diagnosis established PPMS. The patient underwent no adjuvant chemotherapy or radiotherapy and remained recurrence-free during a 30-month follow-up period.
CONCLUSIONS: We report a rare case of PPMS located within the left lung lobe interlobar fissure, featuring Russell body formation within the tumor stroma, a novel finding in PPMS. Furthermore, the histomorphological characteristics of this case highlight the diagnostic challenge it poses, as it may mimic inflammatory myofibroblastic tumor, extraskeletal myxoid chondrosarcoma, or hemangiopericytoma-like fibrous histiocytoma. Therefore, accurate diagnosis necessitates an integrated approach involving morphological, immunohistochemical, and molecular analyses.

Myxofibrosarcoma (MFS) is a unique soft tissue (fibroblastic) sarcoma, characterized by malignant with a locally infiltrative behavior. In this case image, we aimed to report an uncommon/challenging scenario of MFS involving the scatic nerve in which the potential contribution of ultrasound examination has been touched upon.

With the aging world population, the incidence of soft tissue sarcoma (STS) in the elderly gradually increases and the prognosis is poor. The primary goal of this research was to analyze the relevant risk factors affecting the postoperative overall survival in elderly STS patients and to provide some guidance and assistance in clinical treatment. The study included 2,353 elderly STS patients from the Surveillance, Epidemiology, and End Results database. To find independent predictive variables, we employed the Cox proportional risk regression model. R software was used to develop and validate the nomogram model to predict postoperative overall survival. The performance and practical value of the nomogram were evaluated using calibration curves, the area under the curve, and decision curve analysis. Age, tumor primary site, disease stage, tumor size, tumor grade, N stage, and marital status, are the risk variables of postoperative overall survival, and the prognostic model was constructed on this basis. In the two sets, both calibration curves and receiver operating characteristic curves showed that the nomogram had high predictive accuracy and discriminative power, while decision curve analysis demonstrated that the model had good clinical usefulness. A predictive nomogram was designed and tested to evaluate postoperative overall survival in elderly STS patients. The nomogram allows clinical practitioners to more accurately evaluate the prognosis of individual patients, facilitates the progress of individualized treatment, and provides clinical guidance.

YAP1-KMT2A融合肉瘤是一种罕见的软组织肉瘤新亚型，好发于青壮年，形态学与硬化性上皮样纤维肉瘤（SEF）有一定程度重叠，但不表达MUC4。本例患者为34岁女性，左腋下无痛性肿块半年。肿瘤周界相对清楚，由大小形态相对一致的上皮样细胞呈小簇状、短条索状、梁状、巢状或弥漫片状分布于致密胶原化间质中，局部可见血管外皮瘤样结构和地图样坏死。瘤细胞无显著异型性，核分裂象约15个/10 HPF。瘤细胞表达上皮细胞膜抗原、CD99、cyclin D1和BCOR，MUC4阴性。荧光原位杂交显示KMT2A基因易位，二代测序显示YAP1-KMT2A基因融合。常规病理工作中，若遇到形态类似SEF，但不表达MUC4的肿瘤，要考虑到YAP1-KMT2A融合肉瘤的可能性，并行分子检测予以明确。.

OBJECTIVE: Angiosarcoma (AS) is a rare malignancy with considerable heterogeneity seen in its aetiology, anatomical location, and clinicopathological behaviour. Diagnosis is often delayed and prognosis poor. The purpose of this study was to perform a retrospective review of all cases of AS over 10 years at a high-volume regional UK referral centre.
METHODS: We reviewed all cases of AS discussed at the sarcoma multidisciplinary meetings of University Hospitals Birmingham NHS Foundation Trust from September 2013 to August 2023. Demographic and clinicopathologic features at diagnosis, approaches to treatment, and outcomes were compared between four AS subtypes.
RESULTS: A total of 130 cases were identified. The median age at diagnosis was 71 years, with the majority being female (78%). The most common AS subtype was radiation-induced AS (RIAS) (n = 72; 55%), followed by primary cutaneous (n = 28; 22%), primary non-cutaneous (n = 25; 19%), and AS secondary to lymphoedema (n = 5; 4%). Metastases were present at diagnosis in 18% of patients. Treatment was with surgery in the majority of patients (71%). The median survival for the cohort was 30 months (95% CI 20-40), although this differed significantly by AS subtype (p < 0.001), ranging from 5 months in primary non-cutaneous AS to 76 months in RIAS.
CONCLUSIONS: RIAS is the most common AS subtype, with surgery the only potentially curative treatment modality. Overall prognosis varies significantly by subtype. An international consensus on classification of AS subtypes is required to allow meaningful comparisons across studies and/or a prospective multi-centre registry.

There has been growing interest in the use of real-world data (RWD) to address clinically and policy-relevant (research) questions that cannot be answered with data from randomized controlled trials (RCTs) alone. This is, for example, the case in rare malignancies such as sarcomas as limited patient numbers pose challenges in conducting RCTs within feasible timeliness, a manageable number of collaborators, and statistical power. This narrative review explores the potential of RWD to generate real-world evidence (RWE) in sarcoma research, elucidating its application across different phases of the patient journey, from prediagnosis to the follow-up/survivorship phase. For instance, examining electronic health records (EHRs) from general practitioners (GPs) enables the exploration of consultation frequency and presenting symptoms in primary care before a sarcoma diagnosis. In addition, alternative study designs that integrate RWD with well-designed observational RCTs may offer relevant information on the effectiveness of clinical treatments. As, especially in cases of ultrarare sarcomas, it can be an extreme challenge to perform well-powered randomized prospective studies. Therefore, it is crucial to support the adaptation of novel study designs. Regarding the follow-up/survivorship phase, examining EHR from primary and secondary care can provide valuable insights into identifying the short- and long-term effects of treatment over an extended follow-up period. The utilization of RWD also comes with several challenges, including issues related to data quality and privacy, as described in this study. Notwithstanding these challenges, this study underscores the potential of RWD to bridge, at least partially, gaps between evidence and practice and holds promise in contributing to the improvement of sarcoma care.

We describe exciting recent advances in fusion-driven sarcoma etiology, from an epigenetics perspective. By exploring the current state of the field, we identify and describe the central mechanisms that determine sarcomagenesis. Further, we discuss seminal studies in translational genomics, which enabled epigenetic characterization of fusion-driven sarcomas. Important context for epigenetic mechanisms include, but are not limited to, cell cycle and metabolism, core regulatory circuitry, 3-dimensional chromatin architectural dysregulation, integration with ATP-dependent chromatin remodeling, and translational animal modeling. Paradoxically, while the genetic requirements for oncogenic transformation are highly specific for the fusion partners, the epigenetic mechanisms we as a community have uncovered are categorically very broad. This dichotomy prompts the question of whether the investigation of rare disease epigenomics should prioritize studying individual cell populations, thereby examining whether the mechanisms of chromatin dysregulation are specific to a particular tumor. We review recent advances focusing on rhabdomyosarcoma, synovial sarcoma, alveolar soft part sarcoma, clear cell sarcoma, undifferentiated round cell sarcoma, Ewing sarcoma, myxoid/round liposarcoma, epithelioid hemangioendothelioma and desmoplastic round cell tumor. The growing number of groundbreaking discoveries in the field, motivated us to anticipate further exciting advances in the area of mechanistic epigenomics and direct targeting of fusion transcription factors in the years ahead.

BACKGROUND: Limited understanding exists regarding early sarcoma symptoms presented during general practitioner (GP) consultations. The study explores GP visit patterns and recorded diagnoses in the 12 months preceding sarcoma diagnosis.
METHODS: Sarcoma cases diagnosed from 2010 to 2020 were identified through the Netherlands Cancer Registry alongside general practice data. Sarcoma cases were age and gender matched to cancer-free controls (2:1 or 1:1 ratio).
RESULTS: A total of 787 individuals with soft-tissue sarcoma (STS) and 188 individuals with bone sarcoma (BS) were identified. There was a significant difference in monthly GP contacts from 4 months to the last month before STS diagnosis, and 2 months before BS diagnosis between cases and controls. Most prevalent diagnoses recorded by the GP for STS cases included musculoskeletal neoplasm (26.6%), uncomplicated hypertension (15.6%), and cystitis/other urinary infections (12.2%). For BS cases, musculoskeletal neoplasm (42.8%), knee symptoms/complaints (9.7%), and shoulder symptoms/complaints (9.7%) were most frequent.
CONCLUSIONS: A significant difference in GP contacts between cases and controls preceding sarcoma diagnosis. STS cases were predominantly diagnosed with nonspecific symptoms, whereas BS cases with diagnoses more suggestive of BS. Better understanding of the prediagnostic trajectory could aid GPs in early identification of sarcoma.

Despite sharing the same histologic classification, individual tumors in multi metastatic patients may present with different characteristics and varying sensitivities to anticancer therapies. In this study, we investigate the utility of radiomic biomarkers for prediction of lesion-specific treatment resistance in multi metastatic leiomyosarcoma patients. Using a dataset of n=202 lung metastases (LM) from n=80 patients with 1648 pre-treatment computed tomography (CT) radiomics features and LM progression determined from follow-up CT, we developed a radiomic model to predict the progression of each lesion. Repeat experiments assessed the relative predictive performance across LM volume groups. Lesion-specific radiomic models indicate up to a 4.5-fold increase in predictive capacity compared with a no-skill classifier, with an area under the precision-recall curve of 0.70 for the most precise model (FDR = 0.05). Precision varied by administered drug and LM volume. The effect of LM volume was controlled by removing radiomic features at a volume-correlation coefficient threshold of 0.20. Predicting lesion-specific responses using radiomic features represents a novel strategy by which to assess treatment response that acknowledges biological diversity within metastatic subclones, which could facilitate management strategies involving selective ablation of resistant clones in the setting of systemic therapy.