Epigenomic and transcriptomic profiling of solitary fibrous tumors identifies site-specific patterns and candidate genes regulated by DNA methylation.

Solitary fibrous tumor (SFT) is a rare mesenchymal neoplasm which can arise at any anatomic site and is characterized by recurrent NAB2::STAT6 fusions and metastatic progression in 10-30%. The cell of origin has not been identified. Despite some progress in understanding the contribution of heterogeneous fusion types and secondary mutations to SFT biology, epigenetic alterations in extrameningeal SFT remain largely unexplored, and most sarcoma research to date has focused on the use of methylation profiling for tumor classification. We interrogated genome-wide DNA methylation in 79 SFTs to identify informative epigenetic changes. RNA-seq data from targeted panels and data from the Cancer Genome Atlas (TCGA) were used for orthogonal validation of selected findings. In unsupervised clustering analysis, the top 500 most variable CpGs segregated SFTs by primary anatomic site. Differentially methylated genes (DMGs) associated with primary SFT site included EGFR, TBX15, multiple HOX genes and their cofactors EBF1, EBF3, and PBX1, as well as RUNX1 and MEIS1. Of the 20 DMGs that were interrogated on the RNA-seq panel, twelve were significantly differentially expressed according to site. However, with the exception of TBX15, most of these also showed differential expression according to NAB2::STAT6 fusion type, suggesting that the fusion oncogene contributes to transcriptional regulation of these genes. Transcriptomic data confirmed an inverse correlation between gene methylation and the expression of TBX15 in both SFT and TCGA sarcomas. TBX15 also showed differential mRNA expression and 5' UTR methylation between tumors located in different anatomic sites in TCGA data. In all analyses, TBX15 methylation and mRNA expression retained the strongest association with tissue of origin in SFT and other sarcomas, suggesting a possible marker to distinguish metastatic tumors from new primaries without genomic profiling. Epigenetic signatures may further help to identify SFT progenitor cells at different anatomic sites.

Tranexamic acid use in sarcoma surgery patients: A systematic review and meta-analysis.

INTRODUCTION: Perioperative bleeding increases morbidity and mortality in sarcoma patients. Tranexamic acid (TXA), an antifibrinolytic, is widely utilized in non-sarcoma orthopaedic surgeries, but its adoption in sarcoma surgery is hindered by concerns about thrombotic events. METHODS: Searches in Ovid MEDLINE, EMBASE, and CENTRAL were performed without date restrictions. Inclusion criteria encompassed sarcoma patients undergoing surgery with TXA intervention. Two authors independently screened studies, resolved conflicts, and assessed biases. RESULTS: Eight studies met inclusion criteria, comprising 2142 patients. TXA administration varied in dose and timing across studies. Meta-analysis revealed significantly reduced mean blood loss with TXA of -462.5 mL ([95% confidence interval [CI: -596.7, -328.31], p < 0.001) but no difference in transfusion rates (odds ratio [OR] = 0.51 [95% CI: 0.14-1.89]) or venous thromboembolism events (OR = 0.93 [95% CI: 0.40, 2.16]). Study biases were predominantly moderate to high due to retrospective designs and lack of control for confounders. Quality of reporting varied, with limitations identified in outcome reporting and effect size estimation. CONCLUSIONS: Despite evidence of reduced blood loss, the absence of prospective studies limits conclusive recommendations on TXA use in sarcoma surgery. Further research is warranted to determine optimal TXA regimens and assess safety concerns regarding thrombotic events in this patient population.

The utility of intraoperative marrow margin frozen section in extremity bone sarcoma resection.

BACKGROUND AND OBJECTIVES: Intraoperative frozen section analysis is commonly used to evaluate marrow margins during extremity bone sarcoma resections, but its efficacy in the era of magnetic resonance imaging is debated. This study aimed to compare the accuracy of intraoperative frozen section assessment with final pathology, assess its correlation with gross intraoperative margin assessment, and evaluate its impact on surgical decision making. METHODS: Consecutive patients undergoing extremity bone sarcoma resections from 2010 to 2022 at a single sarcoma center were included. Intraoperative frozen section and gross margin assessments were compared to final pathology using positive predictive values (PPV) and negative predictive values (NPV). Changes in surgical decisions due to positive intraoperative margins were recorded. RESULTS: Of 166 intraoperative frozen section marrow margins, four were indeterminant/positive, with two false positive/indeterminant findings and two false negatives compared to final pathology. Gross intraoperative assessment had no false positives and two false negatives. Frozen section analysis yielded a PPV of 50% (95% confidence interval [CI]: 16%-84%) and NPV of 98.8% (95% CI: 97%-100%), while gross assessment had a PPV of 100% (95% CI: 16%-100%) and NPV of 98.8% (95% CI: 97%-100%). Positive frozen section margins led to additional resections in three of four cases. CONCLUSIONS: Intraoperative frozen section analysis did not offer added clinical value beyond gross margin assessment in extremity bone sarcoma resections. It exhibited a low PPV and led to unnecessary additional resections. Gross intraoperative assessment proved adequate for margin evaluation, potentially saving time and resources.

Obesity increases the risk of major wound complications following pelvic resection for bone sarcoma.

BACKGROUND: Given the paucity of data, the objective of this study is to evaluate the association between obesity and major wound complications following pelvic bone sarcoma surgery specifically. METHODS: Patients who underwent pelvic resection for bone sarcoma from 2005 to 2021 with a minimum 6-month follow-up were reviewed. Patients with benign tumors, primary soft tissue sarcomas, local recurrence at presentation, pelvic metastatic disease, and underweight patients were excluded. A major wound complication was defined as the need for a secondary debridement procedure. Differences in baseline demographics, surgical factors, postoperative complications, and functional outcomes were compared between obese and nonobese patients. A multivariate logistic regression was performed to identify independent risk factors for major wound complications, and a Kaplan-Meier analysis to estimate overall survival between both groups. RESULTS: Of the 93 included patients, 21 were obese (body mass index ≥ 30 kg/m2). The obesity group had a significantly higher rate of major wound complication (52% vs. 26%, p = 0.034) and a lower Toronto Extremity Salvage Score at 1-year postoperatively (47.5 vs. 71.4, p = 0.025). Obesity was the only independent risk factor in the multivariate analysis. No differences in overall survival were demonstrated between groups. CONCLUSIONS: Obesity is a significant risk factor for major wound complications in pelvic bone sarcoma treatment. This highlights the importance of careful perioperative optimization and wound management.

Spectrum and patterns of shoulder pathology on MRI in symptomatic elite wheelchair basketball athletes.

BACKGROUND: Wheelchair basketball (WCB) is a popular para-sport adapted for athletes with physical disabilities. Shoulder injuries are commonly reported among WCB athletes. However, the understanding of the specific patterns and characteristics of shoulder injuries in WCB players is currently limited, and there is a lack of comprehensive literature available on this subject. OBJECTIVES: To investigate the spectrum of pathologies observed in elite wheelchair basketball (WCB) athletes referred for MRI evaluation of symptomatic injuries of the shoulder. METHODS: Retrospective review of consecutive elite WCB athletes referred for MRI evaluation of symptomatic shoulder injury. Demographic, clinical, and functional data including international wheelchair basketball federation (IWBF) classification of each athlete were collected. A total of 28 MRI studies were reviewed. Excluding MRI examinations of the same shoulder, 18 study cases were assessed for pathology of the rotator cuff (RC), labrum, long-head of biceps tendon, glenohumeral and acromioclavicular joints, and osseous lesions of the humerus or glenoid. Correlations between clinical-demographic features and MRI findings were statistically evaluated. RESULTS: Supraspinatus tears were observed in 72.2%, infraspinatus tears in 50%, and subscapularis tears in 38.9% shoulders. Articular-sided partial tears frequently involved posterior supraspinatus (88.9%) and anterior infraspinatus (100%). Labral tears were seen in 38.9%, with involvement of the posterosuperior labrum in all tears. Hill-Sachs and osseous Bankart lesions (5.6%), and anterior-inferior labral tears (11.1%), were uncommon findings. Statistically significant correlations were observed of low IWBF point class and non-ambulatory athletes with subscapularis tendinosis (p = 0.015, p = 0.001) and tearing (p = 0.050, p = 0.013), and athletes with limited trunk control with subscapularis tendinosis (p = 0.013). CONCLUSIONS: RC tears are common in elite WCB athletes with pattern of RC and labral tearing suggesting internal (superior-posterior) impingement as a contributory pathoetiologic mechanism. Non-ambulatory, low IWBF point class athletes, as well as those with limited trunk control have a statistically significant increase in subscapularis tendon pathology on MRI.

VIM::KMT2A-rearranged sarcomas: A report of two new cases confirming an entity with distinct histologic features.

The recently described KMT2A-rearranged sarcomas are rare emerging entities where the KMT2A gene fuses with YAP1 and, less commonly, VIM, resulting in two distinct morphologies. Unlike the sclerosing epithelioid fibrosarcoma-like features that characterize tumors with KMT2A::YAP1 fusions, VIM::KMT2A-rearranged sarcomas are more uniformly cellular and lack the extensively sclerotic background seen in the former. Most tumors behave aggressively with metastases on presentation. Here, we describe the clinicopathologic and molecular findings in two additional cases of VIM::KMT2A rearranged sarcomas that arose in the deep soft tissues of adult males. Both tumors were composed of hypercellular fascicles of uniform spindle cells with pale eosinophilic cytoplasm and ovoid nuclei. The stroma had scant delicate collagen with occasional thin-walled ectatic blood vessels and perivascular hyalinization. Immunohistochemical studies showed an unspecific staining pattern with diffuse positivity for CD99 and BCL2 and variable staining for S100 protein. RNA-sequencing detected the presence of VIM::KMT2A gene fusion involving VIM exon 4 and KMT2A exon 2 in both cases. Sarcomas with VIM::KMT2A gene fusions seem to have sufficient morphologic features to warrant distinction from KMT2A-rearranged sarcomas with YAP1 partner. Without the benefit of molecular testing, these tumors pose a diagnostic challenge due to their lack of specific immunohistochemical profile and great morphologic overlap with other monomorphic spindle cell neoplasms.

Mutations involving TGFB and MAPK may be associated with malignancy in granular cell tumors.

Granular cell tumors (GrCTs) are mesenchymal neoplasms of presumed schwannian differentiation that may present as solitary or multifocal lesions with excision usually being curative. A minority of cases, however, show histological features associated with an increased risk for metastasis and are highly aggressive leading to death in about a third of cases. While benign and malignant cases have been shown to harbor mutations in the H + ATPase genes, there is only limited data examining molecular aberrations associated with malignancy. The departmental archives were searched for cases of atypical/malignant GrCTs. Clinical and histopathological features were noted. Whole-exome sequencing was performed. Three cases of malignant GrCTs and one case of atypical GrCTs were included. All three malignant tumors metastasized to distant sites with a median disease-free survival of 16 months and an overall follow-up time of 35 months. Whole-exome sequencing showed mutations involving TGFß and MAPK pathways in all four tumors. Although the cohort size is small, our preliminary findings suggest that mutations involving the TGFß and MAPK pathways may be associated with tumor progression or malignant transformation in GrCT pathogenesis.

Research Experiences via Integrating Simulations and Experiments (REVISE): A Model Collaborative Research Project for Undergraduate Students in CO2 Sorbent Design.

Undergraduate research experiences are an instrumental component of student development, increasing conceptual understanding, promoting inquiry-based learning, and guiding potential career aspirations. Moving one step further, as research continues to become more interdisciplinary, there exists potential to accelerate student growth by granting additional perspectives through collaborative research. This study demonstrates the utilization of a model collaborative research project, specifically investigating the development of sorbent technologies for efficient CO2 capture, which is an important research area for improving environmental sustainability. A model CO2 sorbent system of heteroatom-doped porous carbon is utilized to enable students to gain knowledge of adsorption processes, through combined experimental and computational investigations and learnings. A particular emphasis is placed on creating interdisciplinary learning experiences, exemplified by using density functional theory (DFT) to understand molecular interactions between doped carbon surfaces and CO2 molecules as well as explain underlying physical mechanisms that govern experimental results. The experimental observations about CO2 sorption performance of doped ordered mesoporous carbons (OMCs) can be correlated with simulation results, which can explain how the presence of heteroatom functional groups impact the ability of porous carbon to selectively adsorb CO2 molecules. Through an inquiry-focused approach, students were observed to couple interdisciplinary results to construct holistic explanations, while developing skills in independent research and scientific communications. This collaborative research project allows students to obtain a deeper understanding of sustainability challenges, cultivate confidence in independent research, prepare for future career paths, and most importantly, be exposed to strategies employing interdisciplinary research approaches to address scientific challenges.

Outcome After Surgical Treatment of Dermatofibrosarcoma Protuberans (DFSP): Does it Require Extensive Follow-up and What is an Adequate Resection Margin?

INTRODUCTION: Dermatofibrosarcoma protuberans (DFSP) is a rare cutaneous tumour of indeterminate malignant potential. The mainstay treatment for DFSP is surgical resection. Given the reported high local recurrence rate, the ideal resection margin for DFSP is unclear. The purpose of this study was to ascertain the local recurrence and metastatic rate of DFSP and DFSP with fibrosarcomatous degeneration (FS-DFSP), with specific attention to margin status in an attempt to address the issue of margin adequacy. METHODS: Patients treated for DFSP at a single sarcoma centre were identified from a prospective database. DFSP and FS-DFSP patients with and without prior surgery were included. Patients were followed after surgery to monitor complications, local recurrence and metastasis. RESULTS: The study included 200 patients: 166 patients with DFSP and 34 patients with FS-DFSP. In the DFSP group, nine patients (5.4%) had positive margins, one case (0.6%) developed local recurrence (LR) and no patients developed distant metastases. In the FS-DFSP group, seven patients (20.6%) had positive margins, six patients (17.6%) developed local recurrence (LR) and eight patients (23.5%) developed distant metastases, of which three (37.5%) were in the lungs, one (12.5%) in bone and four (50%) in other soft tissue sites. DISCUSSION AND CONCLUSION: Local recurrence and metastases are extremely rare in patients with DFSP. Achieving a negative as opposed to a wide surgical margin may be sufficient to avoid local recurrence of most DFSP. We suggest that no ongoing surveillance for local or systemic relapse is required for DFSP patients after negative margin resection. For FS-DFSP, we recommend the same surveillance schedule, based on tumour grade, as other soft tissue sarcoma.

A Size-Based Criteria for Flap Reconstruction After Thigh-Adductor, Soft-Tissue Sarcoma Resection.

BACKGROUND: Resection of soft-tissue sarcomas from the adductor compartment is associated with significant complications. Free/pedicled flaps often are used for wound closure, but their effect on healing is unclear. We compared wound complications, oncologic, and functional outcomes for patients undergoing flap reconstruction or primary closure following resection of adductor sarcomas. METHODS: A total of 177 patients underwent resection of an adductor sarcoma with primary closure (PrC) or free/pedicled flap reconstruction (FR). Patient, tumor, and treatment characteristics were compared, as well as wound complications, oncologic, and functional outcomes (TESS/MSTS87/MSTS93). To examine the relative benefit of flap reconstruction, number needed to treat (NNT) was calculated. RESULTS: In total, 143 patients underwent PrC and 34 had FR, 68% of which were pedicled. There were few differences in demographic, tumor, or treatment characteristics. No significant difference was found in the rate of wound complications. Length of stay was significantly longer in FR (18 days vs. PrC 8 days; p < 0.01). Oncologic and functional outcomes were similar over 5 years follow-up. Uncomplicated wound healing occurred more often in FR compared with PrC for tumors with ≥15 cm (NNT = 8.4) or volumes ≥ 800 ml (NNT = 8.4). Tumors ≤ 336 ml do not benefit from a flap, whereas those > 600 ml are 1.5 times more likely to heal uneventfully after flap closure. CONCLUSIONS: Although flap use prolonged hospitalization, it decreased wound healing complications for larger tumors, and in all sized tumors, it demonstrated similar functional and oncologic outcomes to primary closure. Our size-based treatment criteria can help to identify patients with large adductor sarcomas who could benefit from flap reconstruction. LEVEL OF EVIDENCE III: (Retrospective cohort study).

T2-weighted MRI radiomics in high-grade intramedullary osteosarcoma: predictive accuracy in assessing histologic response to chemotherapy, overall survival, and disease-free survival.

OBJECTIVE: To analyze radiomic features obtained from pre-treatment T2-weighted MRI acquisitions in patients with histologically proven intramedullary high-grade osteosarcomas and assess the accuracy of radiomic modelling as predictive biomarker of tumor necrosis following neoadjuvant chemotherapy (NAC), overall survival (OS), and disease-free survival (DFS). MATERIALS AND METHODS: Pre-treatment MRI exams in 105 consecutive patients who underwent NAC and resection of high-grade intramedullary osteosarcoma were evaluated. Histologic necrosis following NAC, and clinical outcome-survival data was collected for each case. Radiomic features were extracted from segmentations performed by two readers, with poorly reproducible features excluded from further analysis. Cox proportional hazard model and Spearman correlation with multivariable modelling were used for assessing relationships of radiomics features with OS, DFS, and histologic tumor necrosis. RESULTS: Study included 74 males, 31 females (mean 32.5yrs, range 15-77 years). Histologic assessment of tumor necrosis following NAC was available in 104 cases, with good response (≥ 90% necrosis) in 41, and poor response in 63. Fifty-three of 105 patients were alive at follow-up (median 40 months, range: 2-213 months). Median OS was 89 months. Excluding 14 patients with metastases at presentation, median DFS was 19 months. Eleven radiomics features were employed in final radiomics model predicting histologic tumor necrosis (mean AUC 0.708 ± 0.046). Thirteen radiomic features were used in model predicting OS (mean concordance index 0.741 ± 0.011), and 12 features retained in predicting DFS (mean concordance index 0.745 ± 0.010). CONCLUSIONS: T2-weighted MRI radiomic models demonstrate promising results as potential prognostic biomarkers of prospective tumor response to neoadjuvant chemotherapy and prediction of clinical outcomes in conventional osteosarcoma.

ZFP64::NCOA3 gene fusion defines a novel subset of spindle cell rhabdomyosarcoma.

Spindle cell rhabdomyosarcoma represents a rare neoplasm characterized by monomorphic spindle cells with a fascicular architecture and variable skeletal muscle differentiation. Following incidental identification of a ZFP64::NCOA3 gene fusion in an unclassified spindle cell sarcoma resembling adult-type fibrosarcoma, we performed a retrospective archival review and identified four additional cases with a similar histology and identical gene fusion. All tumors arose in adult males (28-71 years). The neoplasms were found in the deep soft tissues, two were gluteal, and one each arose in the thigh, abdominal wall, and chest wall. Morphologically, the tumors were characterized by spindle cells with a distinctive herringbone pattern and variable collagenous to myxoid stroma. The nuclei were relatively monomorphic with variable mitotic activity. Three tumors had immunoreactivity for MyoD1, and four contained variable expression of desmin and smooth muscle actin. All cases tested for myogenin, CD34, S100, pankeratin, and epithelial membrane antigen were negative. Targeted RNA sequencing revealed a ZFP64::NCOA3 fusion product in all five tumors. Three patients developed distant metastases, and two ultimately succumbed to their disease within 2 years of initial diagnosis. This study suggests ZFP64::NCOA3 fusions define a novel subtype of rhabdomyosarcoma with a spindle cell morphology and aggressive clinical behavior. The potential for morphologic and immunohistochemical overlap with several other sarcoma types underscores the value of molecular testing as a diagnostic adjunct to ensure accurate classification and management of these neoplasms.

Management of giant cell tumors of the distal radius: a systematic review and meta-analysis.

PURPOSE: The treatment of giant cell tumors (GCT) of the distal radius remains challenging, with no consensus on the optimal surgical management. Surgical management remains the mainstay of treatment with options including intralesional curettage and en-bloc resection with reconstruction. The objective of this systematic review and meta-analysis was to evaluate and compare the outcomes of these two procedures. METHODS: Using OVID-Medline and Embase databases, a systematic literature search was performed. Comparative studies, assessing intralesional curettage and en-bloc resection in patients with GCTs of the distal radius, were included. Data regarding rates of local recurrence, metastasis, overall complications, and functional outcomes, were collected and analyzed. The ROBINS-I tool was utilized for risk of bias appraisal within each study outcome. RESULTS: Thirteen studies (n = 373 patients) reporting on 191 intralesional curettage procedures and 182 en-bloc resections were included in the analysis. The average age of participants was 31.9 (SD ± 2.4) years and average follow-up was 7.1 (SD ± 3.6) years. Patients that underwent intralesional curettage were more likely to develop local recurrence (Risk Ratio (RR) 3.3, 95% CI, [2.1, 5.4], p < 0.00001) when compared to patients that underwent en-bloc resection. In Campanacci grade 3 lesions, the risk for local recurrence was 5.9 (95% CI, [2.2, 16.3], p = 0.0006) times higher in patients that received intralesional curettage. Patients that underwent intralesional curettage showed an 84% reduction in the relative risk of developing overall complications compared to en-bloc resection (95% CI, [0.1, 0.4], p < 0.00001), and a larger decrease in Visual Analog Scale and lower Disabilities of the Arm, Shoulder, and Hand (DASH) scores (p < 0.00001). Risk ratio for developing a local recurrence, with PMMA versus bone graft following an intralesional procedure was not significant (RR 1.2, 95% CI, [0.6, 2.6], p = 0.62). CONCLUSIONS: In the surgical management of GCT of the distal radius, intralesional curettage increased local recurrence compared to en-bloc resection with reconstruction, particularly in grade 3 tumors. However, it led to significantly fewer operative complications, lower pain scores, and improved functional outcomes compared to en-bloc resection. Both treatment options remain relevant in the contemporary management of GCTs of the distal radius. Surgical decision making should include both patient and tumor factors when determining the optimal treatment strategy for these patients. LEVEL 3 EVIDENCE: Meta-analysis of Level 3 studies.

Surgical Outcomes of Primary Dermatofibrosarcoma Protuberans: A Retrospective, Multicenter Study.

BACKGROUND: Dermatofibrosarcoma protuberans (DFSP) is a locally aggressive tumor with a low rate of metastatic disease. Previous series have shown a superiority of Mohs micrographic surgery (MMS) compared with wide local excision (WLE). Likewise, there is paucity of data examining the long-term follow-up of patients. OBJECTIVE: The purpose of the current study was to examine the outcome of surgical treatment of primary DFSP of the trunk and extremities. METHODS: We reviewed 236 patients (115 females, 121 males, mean age 41 ± 15 years) undergoing MMS (n = 81, 34%) or WLE (n = 155, 66%) to treat a primary DFSP. Mean tumor size and follow-up was 4 ± 2 cm and 7 years, respectively. Final margins were negative in 230 (97%) patients. RESULTS: There was no difference (p > 0.05) in patient age, sex, tumor size, negative margin excision, or history of a previous inadvertent excision between patients who underwent WLE and those undergoing MMS. There were two cases of local recurrence and two cases of metastasis, with no difference in the 5-year local recurrence-free survival (98% vs. 99%, p = 0.69) or metastatic-free survival (98% vs. 100%, p= 0.27) between WLE and MMS. CONCLUSION: There was no difference in oncologic outcome comparing MMS with WLE for DFSP outside the head and neck. The goal of treatment for DFSP is to achieve a negative margin, regardless of surgical treatment modalities. A 'less is more' approach to follow-up can likely be taken for patients with completely resected DFSP in easy-to-examine anatomical areas. In these patients, no formal follow-up should be required.

Staging and Surveillance of Myxoid Liposarcoma: Follow-up Assessment and the Metastatic Pattern of 169 Patients Suggests Inadequacy of Current Practice Standards.

BACKGROUND: Unlike other sarcoma subtypes, myxoid liposarcoma (MLS) has a propensity for extra-pulmonary metastases. Computed tomography (CT) scan of the chest, abdomen, and pelvis has become an accepted practice for surveillance. However, recent literature suggests that this may be inadequate. This study aimed to assess the ability of current imaging methods to detect metastases adequately in this population. METHODS: The study identified 169 patients with MLS diagnosed between 2000 and 2016. The timing and location of metastases, the reasons leading to the MLS diagnosis, and the imaging methods were recorded. The locations of metastases were classified into the following categories: pulmonary, soft tissue, bone, retroperitoneal, intraperitoneal, solid organ, and lymph node. RESULTS: An initial diagnosis of metastasis was made at presentation with staging CT scan for 3 (10 %) of 31 patients, with a follow-up surveillance CT scan for 15 (48 %) of the patients or with subsequent imaging obtained in response to patient-reported symptoms for 13 (42 %) of the patients. The proportions of patients who had metastases in each location were as follows: soft tissue (84 %), pulmonary (68 %), intraabdominal (48 %), solid organ (48 %), bone (45 %), lymph node (32 %), and retroperitoneal (29 %). Although 14 patients had bone metastases, only 1 patient had a sclerotic/blastic presentation visualized on CT scan, and the diagnosis for the remaining 13 patients was determined by magnetic resonance imaging (MRI). CONCLUSION: Due to metastatic disease identified outside surveillance imaging for 58 % of the patients, the diversity of locations, and the significant failure of CT and bone scan to identify bone metastases, this study questioned the adequacy of CT scan for surveillance of MLS. Consideration should be given to the use of whole-body MRI for detection of metastasis in MLS.

The Toronto Sarcoma Flap Score: A Validated Wound Complication Classification System for Extremity Soft Tissue Sarcoma Flap Reconstruction.

BACKGROUND: Flap reconstruction plays an important role in limb preservation after wide resection of extremity soft tissue sarcoma (ESTS), but can be associated with high rates of postoperative wound complications. Currently, no standardized system exists for the classification of these complications. This study aimed to develop a standardized classification system for wound complications after ESTS flap reconstruction. METHODS: Outcomes of ESTS flap reconstructions were analyzed in a retrospective cohort of 300 patients. All wound- and flap-related complications were identified and categorized. Based on these data, a scoring system was developed and validated with a prospective cohort of 100 patients who underwent ESTS flap reconstruction. RESULTS: A 10-point scoring system was developed based on the level of intervention required to treat each complication observed in the retrospective cohort. Raters applied the scoring system to the prospective patient cohort. Validation studies demonstrated excellent inter-rater and intra-rater reliability (weighted Cohen's kappa range, 0.82 [95% CI, 0.5-1.0] to 0.99 [95% CI, 0.98-1.0] and 0.95 [95% CI, 0.84-1.0] to 0.97 [95% CI, 0.92-1.0], respectively). The majority of the raters reported the score to be simple, objective, and reproducible (respective mean scores, 4.76 ± 0.43, 4.53 ± 0.62, and 4.56 ± 0.56 on 5-point Likert scales). CONCLUSION: The Toronto Sarcoma Flap Score (TSFS) is a simple and objective classification system with excellent inter- and intra-rater reliability. Universal adoption of the TSFS could standardize outcome reporting in future studies and aid in the establishment of clinical benchmarks to improve the quality of care in sarcoma reconstruction.

Gluteus minimus tendon: MR imaging features and patterns of tendon tearing.

PURPOSE: To highlight the spectrum of pathology and patterns of gluteus minimus tendon tearing observed on MR imaging of the hip. METHODS AND MATERIALS: Retrospective review of consecutive hip MRI exams with findings of gluteus minimus tendon (GMin) pathology. A total of 194 exams in 178 patients (148 female, mean age 61) were reviewed. MRI exams are assessed for GMin: tendinopathy, partial, or complete tendon tears. GMin muscular fatty atrophy, enthesopathic cortical irregularities of the greater trochanter (GT), and peri-trochanteric edema or bursal fluid collections were assessed in all cases. In all cases of complete GMin tendon tearing, position and relationship of GMin tendon were assessed relative to its normal insertion site and adjacent soft tissues. RESULTS: Clinical indications for MR imaging included hip pain (n = 151), and weakness or altered gait (n = 13). Insertional GMin tendinopathy was seen in 72, partial tearing in 81, and complete tendon tearing in 40 cases. Complete tendon tearing without proximal retraction was observed in 38/40 cases with soft tissue continuity visualized between distal tendon fibers and the proximal vastus lateralis muscle. Peri-trochanteric bursal fluid (n = 61), osseous irregularities of the GT (n = 118), and fatty atrophy GMin (n = 102) were statistically associated with partial or complete GMin tendon tearing (p < 0.001). CONCLUSIONS: The spectrum of GMin tendon pathology observed on MR imaging ranges from tendinopathy to complete tears. The majority of complete distal GMin tendon tears from the greater trochanter show continuity of distal tendon fibers with the proximal vastus lateralis, distally tethering and limiting proximal tendon retraction.

Curability of patients with lymph node metastases from extremity soft-tissue sarcoma.

BACKGROUND: Lymph node metastases (LNM) rarely occur in adult extremity soft-tissue sarcoma (STS), affecting approximately 5% of patients. To the authors' knowledge, few studies to date have evaluated the prognosis and survival of patients with LNM. METHODS: A retrospective review was performed of a single-center, prospectively collected STS database. Demographic, treatment, and oncologic data for patients with STS of the extremity with LNM were obtained from clinical and radiographic records. RESULTS: Of 2689 patients with extremity STS, a total of 120 patients (4.5%) were diagnosed with LNM. LNM occurred most frequently among patients diagnosed with clear cell sarcoma (27.6%), epithelioid sarcoma (21.9%), rhabdomyosarcoma (17.3%), angiosarcoma (14.0%), and extraskeletal myxoid chondrosarcoma (9.3%). A total of 98 patients (81.7%) underwent LNM surgical resection. Patients with isolated LNM had a greater 5-year overall survival (57.3%) compared with patients with American Joint Committee on Cancer (AJCC) eighth edition stage IV STS with only systemic metastases (14.6%) or both LNM and systemic disease (0%; P < .0001). Patients with isolated LNM had an overall survival rate (52.9%) similar to that of patients with localized AJCC stage III tumors (ie, large, high-grade tumors) (49.3%) (P = .8). Patients with late, isolated, metachronous LNM had a 5-year overall survival rate (61.2%) that was similar to that of patients with isolated synchronous LNM at the time of presentation (53.6%) (P = .4). CONCLUSIONS: Many different types of STS develop LNM. Patients with extremity STS with isolated LNM should not be considered as having stage IV disease as they are according to the current AJCC eighth edition classification because they have significantly better survival than those with systemic metastases. Patients with isolated, late, metachronous LNM have a survival similar to that of patients with isolated synchronous LNM at the time of presentation. LAY SUMMARY: The results of the current study demonstrated that patients diagnosed with isolated lymph node metastases have a prognosis similar to that of patients diagnosed with localized American Joint Committee on Cancer stage III soft-tissue sarcomas, which also equates to a significantly better overall survival compared with patients with systemic metastases. Therefore, the authors recommend modifications to the most recent eighth edition of the American Joint Committee on Cancer staging system to clearly distinguish patients with isolated lymph node metastases to acknowledge their better prognosis compared with those with systemic metastases.

Extrameningeal solitary fibrous tumors-surgery alone or surgery plus perioperative radiotherapy: A retrospective study from the global solitary fibrous tumor initiative in collaboration with the Sarcoma Patients EuroNet.

BACKGROUND: Solitary fibrous tumor (SFT) is a rare mesenchymal malignancy. Although surgery is potentially curative, the local relapse risk is high after marginal resections. Given the lack of prospective clinical trial data, the objective of the current study was to better define the role of perioperative radiotherapy (RT) in various SFT presentations by location. METHODS: This was retrospective study performed across 7 sarcoma centers. Clinical information was retrieved from all adult patients with extrameningeal, primary, localized SFT who were treated between 1990 and 2018 with surgery alone (S) compared with those who also received perioperative RT (S+RT). Differences in treatment characteristics between subgroups were tested using analysis of variance statistics and propensity score matching. Local control and overall survival rates were calculated from the start of treatment until progression or death from any cause. RESULTS: Of all 549 patients, 428 (78%) underwent S, and 121 (22%) underwent S+RT. The median follow-up was 52 months. After correction for mitotic count and surgical margins, S+RT was significantly associated with a lower risk of local progression (hazard ratio, 0.19: P = .029), an observation further confirmed by propensity score matching (P = .012); however, this association did not translate into an overall survival benefit. CONCLUSIONS: The results from this retrospective study investigating perioperative RT in patients with primary extrameningeal SFT suggest that combining RT with surgery in the management of this patient population is significantly associated with a reduced risk of local failures, especially in patients who have less favorable resection margins and in those who have tumors with a high mitotic count.

Designing a Rational Follow-Up Schedule for Patients with Extremity Soft Tissue Sarcoma.

PURPOSE: The risk of tumor recurrence after resection of soft tissue sarcoma (STS) necessitates surveillance in follow-up. The objective of this study was to determine the frequency/timing of metastasis and local recurrence following treatment for soft tissue sarcoma, and to use these data to justify an evidence-based follow-up schedule. METHODS: Utilizing a prospective database, a retrospective single center review was performed of all patients with minimum 2-year follow-up after resection of a localized extremity STS. Kaplan-Meier estimates were used to calculate the incidence of local recurrence and metastases on an annual basis for 10 years. RESULTS: We identified a total of 230 low-grade, 626 intermediate-grade and 940 high-grade extremity STS and a total of 721 events, 150 local recurrences and 571 metastases. Based on tumor size and grade, follow-up cohorts were developed that had similar metastatic risk. Using pre-determined thresholds for metastatic event, a follow-up schedule was established for each cohort. CONCLUSION: Based on our results we recommend that patients with small low-grade tumors undergo annual follow-up for 5 years following definitive local treatment. Patients with large low-grade tumors, small intermediate-grade and small high-grade tumors should have follow-up every 6 months for the first 2 years, then yearly to 10 years. Only patients with large intermediate- or high-grade tumors require follow-up every 3 months for the first 2 years, then every 6 months for years 3-5, followed by annually until 10 years.