Search Results (1,042)

Background: Soft-tissue sarcomas (STSs) are rare and heterogeneous malignancies with generally poor and unpredictable prognosis. Tertiary lymphoid structures (TLSs) have been identified as favorable prognostic indicators in several cancer types, yet their role in STS remains poorly defined. This study investigates the prognostic relevance of TLS presence, maturity, location and density in resected STSs. Methods: We retrospectively analyzed 219 cases of primary STS surgically resected at the Bergonié Institute (France) between 1990 and 2020. TLSs were assessed for presence, spatial distribution, semi-quantitative density and degree of maturity using CD20 and CD23 immunohistochemistry, categorizing tumors as fully mature TLS-positive (fmTLS⁺) or -negative (fmTLS⁻). RNA sequencing was performed on 126 formalin-fixed paraffin-embedded samples to characterize immune microenvironment profiles. Survival outcomes—including overall survival (OS), time to locoregional progression (TTLRP), and time to distant progression (TTDP)—were analyzed using Kaplan–Meier estimates and Cox proportional hazards models. Results: The presence of fmTLS was significantly associated with improved 5-year OS (p = 0.012) and cause-specific survival (p = 0.006). Unexpectedly, fmTLS⁺ tumors showed a higher rate of local recurrence (22.9% vs. 8.1%, p = 0.002). On multivariate analysis, high-density fmTLS⁺ tumors conferred a 2.68-fold increased risk of locoregional progression (95% CI: 1.28–5.59, p = 0.009). Transcriptomic profiling confirmed a significant correlation between fmTLS⁺ status and a high-immune phenotype (Φ = 0.30, p < 0.001). Conclusions: STSs with fmTLS are associated with improved OS but increased risk of local recurrence. These findings support fmTLS as a dual prognostic biomarker and highlight the need for tailored surveillance and adjuvant strategies in fmTLS⁺ patients. Full article

Background/Objectives: The aim of this study was to develop and validate a robust, radiomics-based classification model that uses pre-treatment MRI to non-invasively differentiate among major soft tissue sarcoma (STS) subtypes and a benign mimic. Methods: In this retrospective study, a cohort of 332 patients with biopsy-proven leiomyosarcoma, myxofibrosarcoma, myxoid liposarcoma, dedifferentiated liposarcoma, and undifferentiated pleomorphic sarcoma, along with the benign mimic intramuscular myxoma, was analyzed. Pre-treatment T1-weighted fat-saturated contrast-enhanced and T2-weighted fat-saturated MRI sequences were used for analysis. Following manual tumor segmentation, 1240 three-dimensional radiomic features were extracted. An XGBoost classifier was trained and validated using a robust 250-iteration bootstrap framework with nested cross-validation to ensure rigorous feature selection and unbiased performance evaluation. The model’s performance was assessed independently on T1-only, T2-only, and combined T1+T2 feature sets. Results: The combined T1 and T2 model achieved superior performance with an accuracy of 0.68 ± 0.04 and an AUC of 0.92 ± 0.02. At the subtype level, balanced accuracy was highest for intramuscular myxoma (0.91 ± 0.05), dedifferentiated liposarcoma (0.84 ± 0.06), and leiomyosarcoma (0.83 ± 0.05). SHAP analysis identified key features driving predictions, such as low T2 GLSZM Zone Size Entropy for myxoma and high T2 GLSZM Gray-Level Variance for leiomyosarcoma, which aligns with known pathological characteristics. Misclassifications predominantly occurred between subtypes with overlapping radiomic profiles. Conclusions: Radiomics applied to pre-treatment MRI enables robust, non-invasive classification of STS subtypes, demonstrating strong clinical potential for improving diagnostic confidence and informing triage strategies. Full article

Background: Megaprosthetic reconstruction is the standard of care for limb salvage after tumor resection around the knee, but the full burden of unplanned revision surgery is rarely reported as a structured composite outcome. We evaluated 241 consecutive patients over 21 years at a tertiary orthopedic oncology center. Methods: This retrospective cohort included 241 patients (160 distal femur, 78 proximal tibia, three combined) treated between 2003 and 2024. Revision-free survival (RFS, composite of any unplanned revision or amputation) and amputation-free survival were estimated by Kaplan–Meier analysis; independent predictors were identified by Cox regression. A pre-specified major-event composite (amputation, implant removal, or recurrence resection) was used for sensitivity analysis. Results: Mean age was 34.9 ± 19.5 years; mean follow-up was 120.2 months. Negative resection margin (R0) was achieved in 85.5% (206/241). Unplanned revision was required in 25 patients (10.4%); overall limb salvage was 92.9%. Five-year RFS was 73.8% (distal femur) vs. 65.0% (proximal tibia; p = 0.084), and 5-year limb salvage was 88.9% vs. 84.3% (p = 0.081). Surgical margin was strongly associated with outcome: 5-year RFS 75.4% (R0) vs. 48.7% (R1/R2; p < 0.001); 5-year limb salvage 90.6% vs. 71.5% (p = 0.003). On exploratory multivariate Cox analysis, proximal tibia site and positive margin were associated with worse revision-free survival; within the proximal tibia subgroup, absence of gastrocnemius flap coverage was also associated with worse outcome (interpreted with caution given the small flap subgroup, n = 11, and limited event count). Conclusions: In this single-center series, megaprosthetic reconstruction around the knee achieved acceptable revision-free survival and limb salvage. Surgical margin status was the strongest independent predictor of both endpoints, reinforcing the well-established importance of oncologic margin quality and site-specific soft tissue strategies. Full article

Ultrasonography can assist in the preoperative evaluation and postoperative surveillance of superficial soft tissue tumors of the hand. We present an ultrasound-based identification of a neurofibroma in a patient with neurofibromatosis type 1 (NF1). A 45-year-old male presented with a slowly enlarging subcutaneous mass over the dorsal aspect of the hand associated with localized paresthesia. Physical examination revealed characteristic NF1 stigmata, including café-au-lait macules, axillary freckling, and craniofacial asymmetry suggestive of sphenoid wing dysplasia. High-resolution ultrasonography demonstrated a well-defined hypoechoic fusiform lesion along the course of a digital nerve, suggestive of a peripheral nerve sheath tumor. Magnetic resonance imaging showed a T2-hyperintense lesion compatible with a nerve sheath tumor. Surgical excision was subsequently performed, and histopathological examination confirmed a localized neurofibroma with incorporation of native nerve fascicles within a myxoid spindle cell matrix. Serial postoperative ultrasonography at 3 and 12 months demonstrated no evidence of local recurrence. This case highlights ultrasonography as a practical, radiation-free, and cost-effective modality for both preoperative assessment and longitudinal follow-up of superficial NF1-associated neurofibromas. Full article

We report an extremely rare case of intra-articular myopericytoma of the knee. A 66-year-old man presented with a 10-year history of knee pain and a slowly enlarging soft, tender, and elastic mass. Magnetic resonance imaging revealed a well-enhanced intra-articular lesion; however, the findings were nonspecific and raised a broad differential diagnosis of vascular, perivascular, and malignant soft-tissue tumors. Incisional biopsy followed by marginal excision confirmed the diagnosis of myopericytoma. Although typically benign and indolent, myopericytomas can mimic both benign and malignant lesions, necessitating histopathological evaluation. At 5 years after surgery, the patient remained recurrence-free. Full article

Soft tissue sarcomas (STS) are locally invasive and aggressive tumors that occur spontaneously in humans, dogs, and cats. High-intensity focused ultrasound (HIFU) is a non-invasive ablation technology that has been explored in canine but not feline STS. The objective of this pilot study was to determine the in vivo safety and feasibility of HIFU ablation for feline STS and to investigate the impact of HIFU on the acute immunological response. Client-owned cats diagnosed with spontaneous STS were recruited. Computed tomography (CT) scans of the chest, abdomen, and tumor were performed prior to treatment for staging and treatment planning. A commercially available HIFU unit (Echopulse, Theraclion, Malakoff, France) was used to target portions of solid tumors before standard-of-care surgical resection. Ablation efficacy and local immunological response were characterized using histopathological and immunohistochemical assessments. Acute safety was monitored with physical examinations, owner reports, and CBC/serum biochemistry. Multiplex serum cytokine levels were used to evaluate the systemic immune response. A total of three cats diagnosed with STS were recruited and treated. No significant adverse events attributed to HIFU treatment were noted in this pilot study. In treated areas, hemorrhage as well as coagulative and lytic necrosis were observed microscopically and were more extensive than in untreated tissues. There was a statistically significant difference in the level of serum MCP-1 after HIFU treatment, but no significant changes in any other analytes. No differences in the infiltration of CD3-, CD79a-, or IBA1-positive cells were noted between treated and untreated samples. Overall, findings suggested that HIFU may offer a viable alternative to conventional therapies for feline STS, with pilot results showing effective tumor ablation in cats with STS without significant adverse events. Some preliminary evidence of immunomodulation following treatment was observed, but HIFU as an immunotherapeutic treatment option needs to be further investigated. Full article

Background/Objectives: Trichoblastoma is a benign follicular adnexal tumor that typically arises on the head and neck. Large variants at atypical locations pose considerable diagnostic challenges because their clinical presentation can be indistinguishable from malignant soft tissue neoplasms. Herein, we describe a case of trichoblastoma presenting as a large subcutaneous thigh mass that was correctly diagnosed by fine-needle aspiration cytology. Case Presentation: A 49-year-old male presented with a 7 cm, slowly enlarging, subcutaneous mass in the left thigh of 20 years’ duration. Magnetic resonance imaging raised the possibility of a low-grade sarcoma. Fine-needle aspiration cytology yielded cohesive clusters of basaloid cells with peripheral palisading, delicate spindle-shaped follicular stromal cells intimately admixed with the epithelial component, and orangeophilic keratinous material in the background. The absence of nuclear atypia, mitotic figures, and mucinous stroma supported a preoperative cytological diagnosis of a benign follicular germinative tumor consistent with trichoblastoma, thereby guiding conservative surgical excision. Histopathological examination confirmed the diagnosis. Immunohistochemistry revealed focally positive BerEP4, CD34-positive stroma, negative androgen receptor, and positive bcl-2, consistent with trichoblastoma and distinguishing the tumor from basal cell carcinoma. The patient remained recurrence-free 12 months after surgery. Conclusions: Careful assessment of characteristic cytomorphological features, particularly a dual population of basaloid epithelial cells with peripheral palisading and specialized follicular stromal cells, is vital for the accurate preoperative cytological characterization of trichoblastoma, even at atypical anatomical sites. Full article

Appendicular soft tissue sarcoma (aSTS) is a group of highly heterogeneous tumors of mesenchymal origin for which standard care usually includes surgical resection with or without radiation therapy. The main goal of surgical treatment in aSTS is to achieve wide tumor resection with negative margins while promoting the best function possible for the affected limb. Orthoplastic surgery represents the concept of a multidisciplinary approach comprising a synergistic collaboration between orthopedic and plastic surgeons. The development of this philosophy allows us to push forward the concept of limb salvage surgery for sarcomas, even when dealing with extremely complex cases. Reconstruction techniques integrated with orthoplastic principles range from simple to highly complex surgeries. Vascularized auto- or allo-graft tissue transfers illustrate how far reconstruction options can go, allowing for repair of large soft tissue defects or even restoration of muscle function in key anatomic segments after oncological resection. The reported experience with orthoplastic philosophy in aSTS suggests that it is a feasible and reproducible strategy that can achieve limb salvage rates above 90%, optimal oncologic local control characterized by more than 95% of wide margin resection, and improved functional and esthetic results. Most patients with aSTS treated under orthoplastic principles present good-to-excellent postoperative Musculoskeletal Oncology Society (MSTS) scores, confirming the advantages of this comprehensive approach. While there is significant experience with the orthoplastic approach for trauma cases, the road still needs to be paved for musculoskeletal oncologic reconstruction. Nonetheless, the results are promising and could inspire a wider adoption of structured orthoplastic protocols for sarcoma patient care. Herein, the authors explore the current practice regarding the application of collaborative orthoplastic approaches for the management of appendicular soft tissue sarcomas, reporting on outcomes and elaborating on future trends. Full article

Plexiform neurofibromas (pNF1s) are benign peripheral nerve sheath tumors caused by NF1 loss, leading to dysregulated RAS/mitogen-activated protein kinase (MAPK) signaling. While the mitogen-activated protein kinase kinase (MEK) inhibitors, selumetinib and mirdametinib, can reduce tumor volume, surgical resection remains the primary treatment for immediate debulking and symptom relief. Complete removal is often limited by tumor infiltration along nerve plexuses, and residual tumors may undergo postsurgical tissue remodeling, producing localized regions of stiffened extracellular matrix (ECM). The impact of ECM stiffness on pNF1 growth and drug responses remains unclear. Using immortalized patient-derived pNF1 tumor cell lines cultured in 3D hydrogels with defined stiffness (1.5 kPa, soft; 7 kPa, stiff), we found that stiff ECM promoted spread morphology, increased growth, and progressive intracellular softening. Stiff ECM also reduced lysyl oxidase (LOX) expression, suggesting mechanoadaptive ECM remodeling, and increased P-glycoprotein expression. Under the same conditions, stiff ECM was associated with reduced sensitivity to selumetinib. These results provide the first evidence that ECM stiffening, including that plausibly associated with postsurgical remodeling, may contribute to pNF1 growth and reduced sensitivity to selumetinib in this 3D pNF1 culture model. Our findings highlight mechanobiology as a key regulator of tumor behavior and support further investigation of ECM-targeted strategies to improve outcomes in neurofibromatosis type 1 (NF1). Full article

Background/Objectives: Primary spinal sarcomas, encompassing both bone and soft tissue histotypes, demand individualized reconstruction due to heterogeneous tumor biology, anatomic complexity, and host environments compromised by radiation, systemic therapy, or prior surgery. This narrative review reframes post-resection spinal reconstruction through a precision-medicine lens. Methods: A structured literature review was performed using PubMed and Scopus, targeting articles published between 2000 and 2026. Searches encompassed spinal sarcoma reconstruction, radiation and fusion, biologic reconstruction, and emerging technologies. Results: Tumor grade, radiation exposure, and systemic therapy timing emerge as multiplicative determinants of reconstructive environment quality, with drug-class-specific perioperative effects warranting stratified management. Vascularized bone grafts achieve reliable fusion in compromised hosts where avascular constructs fail. A precision-oriented reconstructive ladder is proposed as a conceptual, hypothesis-generating framework to guide strategy selection. Hybrid PSI-VBG constructs may further expand reconstructive possibilities. The evidence base remains largely composed of small, retrospective series. Conclusions: Individualized strategies anchored in tumor biology and host environment are the cornerstone of durable spinal sarcoma reconstructions. The proposed framework requires prospective, multi-institutional validation. Standardized outcome definitions, prospective registries, and histotype-stratified analyses are needed to advance the field. Full article

Soft tissue sarcomas (STS) comprise a rare and highly heterogeneous group of mesenchymal-derived malignancies, accounting for less than 1% of all cancers and characterized by diverse histologic and molecular subtypes. Despite their low incidence, STS account for a disproportionate burden of cancer-related morbidity and mortality, largely driven by their risk of metastatic dissemination. Early detection of metastatic spread is a cornerstone of preoperative staging, treatment planning, and postoperative monitoring in patients with STS. Although conventional imaging modalities remain fundamental for surveillance of metastatic disease, they may fail to accurately detect metastatic sites and provide limited insight into tumor biology. Advances in precision medicine have positioned liquid biopsy as a minimally invasive approach for the analysis of tumor-derived material, facilitating characterization of tumor biology and identification of prognostic biomarkers. Circulating tumor cells (CTCs) represent intact and viable tumor cells that provide unique genomic and phenotypic traits that could not be assessed using acellular tumor-derived material. They have emerged as promising biomarkers for monitoring disease progression, assessing treatment response, and stratifying prognosis. Particularly, their clinical value as prognostic biomarkers has been established in epithelial-derived malignancies. Despite these advances, the role of CTCs in STS remains largely investigational, mainly due to STS heterogeneity and the lack of standardized protocols for detection across platforms. Therefore, this narrative review summarizes the biomolecular mechanisms underlying CTCs in STS, including the role of phenotypic plasticity in tumor intravasation, anoikis resistance and its interaction with the tumor microenvironment, and stem cell-like phenotypes in tumor initiation at distant sites. Furthermore, we discuss current methodologies for CTC detection, highlighting emerging approaches developed to address the limitations of conventional methods. Finally, we provide a critical overview of subtype-specific detection strategies, as well as their clinical implications in treatment response monitoring and prognostic assessment. Full article

The sharp dose gradients that underpin the dosimetric advantage of particle therapy over photon therapy can be undermined by the interplay effects due to intra-fraction motion in modern pencil beam scanning systems. Fluoroscopy-Guided Particle Therapy (FGPT) offers a promising path to improved motion management through real-time tracking of tumors or surrogate signals. The advent of flat-panel detector (FPD)-based technology has enabled tighter integration of fluoroscopy/fluorography into treatment units and accelerated clinical adoption and research, with commercial systems such as Hitachi’s Real-time Gated Particle Therapy (RGPT) now available. However, the need for implanted fiducial markers, with the associated invasiveness and risk of complications, limits the utility of RGPT to a few anatomic sites in selected patients. The full potential of FGPT, therefore, depends on reliable marker-less tumor tracking, which remains challenging because soft-tissue targets are obscured by overlapping anatomy along the X-ray path, leading to reduced reliability of traditional image-registration algorithms in the projection domain. Recent advances in deep learning and AI-driven image registration have renewed hope for overcoming these barriers, enabling real-time marker-less tracking for particle therapy. This review outlines the evolution of fluoroscopy technology from image intensifier (II) to FPD-based systems, summarizes historical and recent vendor-supported FGPT strategies, and surveys emerging AI-based algorithms in the literature. A general review of machine learning-based image registration is provided, challenges in generalizability and interpretability are highlighted, and potential paths toward reliable, clinically deployable FGPT are discussed. Full article

Hepatic echinococcosis, caused by Echinococcus species, remains a significant global health concern, with cystic echinococcosis (CE) being widespread and alveolar echinococcosis (AE) representing a rarer but more aggressive form. CE generally demonstrates characteristic imaging features, allowing straightforward diagnosis, whereas atypical presentations can closely mimic other hepatic lesions, leading to diagnostic uncertainty. AE poses an even greater diagnostic challenge due to its infiltrative, tumor-like growth pattern. Magnetic resonance imaging (MRI), with its superior soft-tissue contrast and multiplanar capabilities, plays a crucial role in the evaluation of AE and atypical CE cases. This pictorial review summarizes MRI features of hepatic echinococcosis, detailing both typical and atypical appearances, and emphasizes key criteria for differentiating hydatid cysts from other cystic or solid hepatic lesions. By consolidating imaging findings and discussing relevant differential diagnoses, this review aims to improve diagnostic accuracy, guide clinical management, and increase radiologists’ awareness of echinococcosis in both endemic and non-endemic regions. Full article

Background/Objectives: Myxoid liposarcoma (MLS) is a malignant soft-tissue tumor and the second-most common subtype of liposarcoma, often occurring in the lower limbs of middle-aged patients. Case Presentation: A 38-year-old male patient presented to the ultrasound outpatient clinic with a large mass in the right femoral region. It has been present for 15 years and mostly stable in size. Over the last two years, it has been slowly increasing in size, more rapidly in the previous 10 months, and has started to limit his range of motion. After multiparametric ultrasound and magnetic resonance imaging evaluation, the proposed diagnosis was myxoid liposarcoma. Following imaging workup, the patient was referred to the tertiary sarcoma center, where a biopsy was performed, and pathohistological diagnosis was low-grade myxoid liposarcoma. Contrast-enhanced computed tomography (CT) evaluation of the thorax, abdomen, and pelvis showed no signs of dissemination, and CT angiography showed no signs of vessel infiltration. Plastic surgery and vascular surgery specialists performed the extirpation of the mass with the partial resection of the adjacent sartorius muscle and the complete resection of the great saphenous vein. Subsequent pathohistological analysis of the mass and local lymph nodes showed clear surgical margins and no lymphatic or vascular invasion. The patient is currently under regular surveillance by an oncology specialist and awaiting adjuvant radiotherapy. Conclusions: A multidisciplinary approach is essential in the management of patients with MLS, as it provides a tailored, individualized assessment from diagnosis through treatment to ensure the best possible outcome. Full article

The use of digitized slides for histopathological diagnosis has become common in veterinary pathology, and the validation of diagnostic techniques that are extrapolated from the evaluation of glass slides is needed. The goal of this study is to evaluate the efficiency of counting mitotic figures in physical glass slides and digitized slides of cutaneous tumors of dogs and cats. The mitotic count was performed by three pathologists on glass and digitized slides of ninety skin tumors, including 30 squamous cell carcinomas in dogs and cats, 30 mast cell tumors and 30 soft tissue tumors in dogs. An additional assessment of cellular proliferation was performed with immunohistochemistry for Ki67. Spearman’s correlation for the mean count of mitotic figures between the three observers on physical and digitized slides demonstrated a strong positive correlation for squamous cell carcinomas and mesenchymal tumors and a moderate correlation for mast cell tumors. Inter-observer agreement was moderate between the two methods. In conclusion, the results found suggest that digitized slides can be used reliably for mitotic figure counting in cutaneous neoplasms in small animals, without compromising their classification or prediction of prognosis. Full article