(Neo)adjuvant treatment in localised soft tissue sarcoma: The unsolved affair

Histopathological features of chest wall masses: a systematic review

Chest wall masses can be caused by trauma, infections, inflammation, or cancer. These tumors can be benign or malignant and originate from different structures of the chest wall. This systematic review aimed to investigate the histopathological characteristics of chest wall masses. The study followed the PRISMA guidelines. PubMed, Scopus, and Web of Science databases were searched for case series that reported the histopathological features of chest wall masses, without any restrictions on the date. The risk of bias was assessed using the JBI critical appraisal tools. Nine studies were included in the final review. Studies included a total of 1,279 patients with chest wall masses, with diverse age ranges. Biopsy methods such as fine-needle aspiration biopsy (FNAB), cutting needle biopsy, and surgical resection biopsy were used to evaluate the pathology of the masses. The rate of malignancy in chest wall masses varied depending on the biopsy method used, ranging from 27.12% in needle biopsy to 47.16% in surgical resection biopsy. The overall rate of malignancy in chest wall tumors was 31.27%. About one-third of the chest wall masses are malignant, emphasizing the importance of accurate diagnosis and appropriate treatment selection. Choosing the proper biopsy method is crucial for achieving successful outcomes and reducing mortality rates. Further research with larger sample sizes and improved reporting is needed to enhance our understanding of chest wall tumor pathology and improve patient outcomes.

Anlotinib versus Placebo as Adjuvant Therapy for Localized High-Grade Soft-Tissue Sarcomas: A Phase II, Double-Blinded, Randomized Controlled Trial

PURPOSE

We aimed to investigate the efficacy and safety of anlotinib as adjuvant targeted therapy for completely resected localized high-grade soft-tissue sarcomas (STS).

PATIENTS AND METHODS

Patients with localized high-grade STS after complete resection were randomly assigned in a 1:1 ratio to receive either oral 12 mg anlotinib or placebo once daily on days 1 to 14 every 21 days as a cycle, with up to six cycles until disease relapse, unmanageable toxicity, or death. The efficacy and safety were analyzed. This trial was the first trial exploring adjuvant targeted therapy for STS (NCT03951571).

RESULTS

Between June 2019 and November 2023, 88 patients were randomly assigned to receive anlotinib (n = 44) or placebo (n = 44). With a median follow-up of 30.95 months, the 1- and 2-year disease-free survival rates were 88% and 77% in the anlotinib group compared with 64% and 58% in the placebo group, respectively. Compared with patients treated with surgery alone, patients receiving adjuvant anlotinib combined with surgery had a reduced risk of disease recurrence [HR, 0.47; 95% confidence interval (CI), 0.22-1.00; P = 0.0445]. Based on the tumor histology, the reduced risk of disease recurrence with anlotinib versus placebo was observed in patients with myxofibrosarcoma (HR, 0.54; 95% CI, 0.17-1.65; P = 0.2698) and undifferentiated pleomorphic sarcoma (HR, 0.58; 95% CI, 0.12-2.87; P = 0.4971). Four patients discontinued anlotinib: two for proteinuria/hematuria (2/44, 5%) and two for poor healing of surgical wound (2/44, 5%).

CONCLUSIONS

Compared with surgery alone, adjuvant anlotinib following surgery reduces the incidence of disease relapse in localized high-grade STS, with acceptable toxicity.

Challenges, Treatment Strategies, and Surgical Techniques in the Management of Spermatic Cord Sarcomas

Spermatic cord sarcomas (SCS) are a group of mesenchymal tumors whose rarity and anatomical location often lead to clinical misdiagnosis such as inguinal hernia, testicular tumor, or other conditions. Any inguinoscrotal mass with suspicious characteristics should prompt clinicians to perform imaging assessments (such as ultrasound or, in uncertain cases, magnetic resonance imaging (MRI)) and refer the patient promptly to a specialized center. Histological characterization of all suspicious masses via percutaneous biopsy is recommended, with staging completed through computed tomography (CT) scan for confirmed cases. Optimal management is multidisciplinary and should consider both the tumor's histological subtype and specific characteristics of the tumor and patient. Radiotherapy and chemotherapy, while awaiting more robust data in the literature, are valuable adjuncts to surgery, which remains the cornerstone of treatment. Surgery should also be proposed for patients who initially underwent nonspecialist procedures, as a completion approach. The surgical strategy involves en bloc resection through radical orchifunicolectomy, ipsilateral hemiscrotectomy, ligation of the spermatic cord at the internal inguinal ring, and, where necessary, resection of the inguinal canal. Reconstruction may employ mesh or pedicled flaps. The prognosis of SCS, when treated at referral centers, is superior to that of mesenchymal tumors at other sites, underscoring the need for early recognition and prompt multidisciplinary care.

Alveolar Soft Tissue Sarcoma: Correlation of MRI Features With Histological Grading and Patient Prognosis

BACKGROUND

Alveolar Soft Part Sarcoma (ASPS) is a rare, aggressive cancer whose diagnosis and treatment depend on histological grading. However, tumor variability can lead to underestimation, affecting treatment, and patient survival.

OBJECTIVE

To evaluate MRI features associated with Grade III ASPS and to determine the relationship between MRI features and patient prognosis.

STUDY TYPE

Retrospective analysis.

SUBJECTS

Sixty-seven patients with ASPS were included with 37 males and 30 females (M/F = 1.23) follow-up and survival analysis on 50 patients.

FIELD STRENGTH/SEQUENCE

A 3.0 T, T1WI-FSE, T2WI-FSE, DWI-EPI, DCE-MRI (gradient echo).

ASSESSMENT

MRI features (margin, peritumoral oedema, peritumoral enhancement, necrosis, vascular flow void signal, heterogeneous signal intensity [SI] at T1WI and T2WI, ADCmean, time-intensity curve [TIC] type, distant metastasis, and bone invasion) and histological grading were independently evaluated by three radiologists and two pathologists, with Grade III considered high-grade.

STATISTICAL TESTS

The chi-square or Fisher's exact test was used to assess the correlation between MRI features and histological grading. Multivariable binary logistic regression identified independent factors associated with high-grade tumors. The Kaplan-Meier method and Cox proportional hazards model were used to calculate hazard ratios for MRI features.

RESULTS

Tumor necrosis, heterogeneous SI at T2WI ≥50%, and ADCmean were associated with high-grade ASPS. Tumor necrosis was an independent factors associated with local relapse-free survival (odds ratio [OR], 3.88). TIC type was associated with 5-year survival rate (OR, 2.80) and local relapse-free survival (OR, 2.69). Heterogeneous SI at T2WI ≥50% was associated with 5-year survival (OR, 4.00), local relapse-free survival (OR, 5.58), and local relapse-free survival (OR, 4.84).

DATA CONCLUSION

MRI features including tumor necrosis, heterogeneity of SI at T2WI, ADCmean, and TIC type aid in assessing ASPS grading and prognosis.

EVIDENCE LEVEL

4 TECHNICAL EFFICACY: Stage 5.

Pathologic complete response in patients with localized soft tissue sarcoma treated with neoadjuvant therapy and its correlation with clinical outcomes: A systematic review

Soft tissue sarcomas (STS), comprising approximately 1% of adult solid malignancies, are primarily treated with surgery, with the choice of perioperative treatment being a challenging and highly individualized decision. Clinical trials assessing neoadjuvant modalities in STS predominantly use clinical outcomes or radiologic response as endpoints, with pathologic complete response (pCR) not being employed as a designated study endpoint. Our systematic review aimed to assess the rates of pCR in clinical trials of different neoadjuvant modalities for STS and its correlation with patient clinical outcomes. 23 phase I, II and III studies were included, from which data regarding rates of pCR with each treatment, as well as correlation of pCR with clinical outcomes were retrieved. In 16 trials that assessed pCR, the percentage of patients who achieved a pCR ranged from 8 to 58%. Most of these trials did not aim to establish an association between pCR and clinical outcomes. However, among those that did investigate this correlation, a positive association was identified between pCR and both 5-year disease-specific survival (DSS) and 5-year overall survival (OS). While pCR serves as a crucial marker guiding treatment decisions in other neoplasms like triple negative breast cancer and urothelial cancer, it is not yet used in a similar setting for STS. Our findings indicate variability in patients achieving pCR across different neoadjuvant treatments for STS and a possible positive correlation with patient outcomes. Consequently, we propose considering pCR as a surrogate endpoint in future prospective trials for STS.

Metabolic targeting of cancer associated fibroblasts overcomes T-cell exclusion and chemoresistance in soft-tissue sarcomas

T cell-based immunotherapies have exhibited promising outcomes in tumor control; however, their efficacy is limited in immune-excluded tumors. Cancer-associated fibroblasts (CAFs) play a pivotal role in shaping the tumor microenvironment and modulating immune infiltration. Despite the identification of distinct CAF subtypes using single-cell RNA-sequencing (scRNA-seq), their functional impact on hindering T-cell infiltration remains unclear, particularly in soft-tissue sarcomas (STS) characterized by low response rates to T cell-based therapies. In this study, we characterize the STS microenvironment using murine models (in female mice) with distinct immune composition by scRNA-seq, and identify a subset of CAFs we termed glycolytic cancer-associated fibroblasts (glyCAF). GlyCAF rely on GLUT1-dependent expression of CXCL16 to impede cytotoxic T-cell infiltration into the tumor parenchyma. Targeting glycolysis decreases T-cell restrictive glyCAF accumulation at the tumor margin, thereby enhancing T-cell infiltration and augmenting the efficacy of chemotherapy. These findings highlight avenues for combinatorial therapeutic interventions in sarcomas and possibly other solid tumors. Further investigations and clinical trials are needed to validate these potential strategies and translate them into clinical practice.

SOFT TISSUE SARCOMA - SANTA CASA DE SÃO PAULO EXPERIENCE FROM 2006 TO 2019

Objective

To conduct an epidemiologic review, analyzing treatment, evolution, and survival of soft tissue sarcomas.

Methods

Retrospective study based on medical records of patient with STS treated by the Orthopedic Oncology Group at the Santa Casa de São Paulo, from 2006 to 2019. Data from 121 patients were analyzed according to age, sex, histological type, tumor location, treatment, previous surgery in a non-specialized service, local recurrences, lung metastases, and survival analysis.

Results

The most frequent location was the thigh. Patients who underwent surgery with a non-specialized group had higher rates of local recurrence and those with pulmonary metastasis had a lower survival rate.

Conclusion

STS can occur at any age and the prevalence of the histological type depends on the patients' age group. Level of Evidence II, Prognostic Study.

Primary leiomyosarcoma of the inferior vena cava in a pediatric case: a case report and literature review

BACKGROUND

Leiomyosarcoma is classified as a soft tissue sarcoma. In adults, leiomyosarcoma is the most common malignancy affecting the vascular system; however, vascular leiomyosarcoma in children is extremely rare as most pediatric soft tissue tumors are rhabdomyosarcomas. The survival rate is very low, and incomplete resection is a poor prognostic factor. There is also a high rate of distant recurrence, with the lungs and liver being the most common sites of metastasis. There is no established effective chemotherapy, and complete surgical resection is the only potentially curative treatment for leiomyosarcoma.

CASE PRESENTATION

A 15-year-old female patient with no significant medical history presented with severe upper abdominal pain and was admitted. Abdominal contrast-enhanced computed tomography and magnetic resonance imaging showed a large retroperitoneal tumor protruding into the lumen of the inferior vena cava behind the liver and multiple small nodules, and metastasis to the liver was suspected. The tumor was 6 × 4 × 5 cm in diameter, located just behind the hepatic hilar structures, and was suspected to infiltrate into the right portal vein. The tumor was diagnosed as a leiomyosarcoma through an open tumor biopsy. As the multiple liver metastases were located only in the right lobe of the liver on imaging, we performed tumor resection with right hepatectomy and replacement of the inferior vena cava (IVC). The postoperative course was uneventful; however, on postoperative day 51, distant metastatic recurrences were found in the remaining liver and right lung. The patient was immediately started on chemotherapy and trabectedin proved to be the most effective drug in the treatment regimen; however, severe side effects, such as hepatotoxicity, prevented timely administration, and the patient passed away 19 months after surgery.

CONCLUSIONS

IVC resection and reconstruction combined with right hepatectomy were able to be safely performed even in a pediatric case. To improve the prognosis of leiomyosarcoma with multiple metastases, an effective treatment strategy combining surgical treatment and chemotherapy, including molecularly targeted drugs, should be established as early as possible.

Soft-tissue sarcoma in adults: Imaging appearances, pitfalls and diagnostic algorithms

This article provides an overview of the current knowledge regarding diagnostic imaging of patients with soft-tissue sarcomas, which is a heterogeneous group of rare mesenchymal malignancies. After an initial contextualization, diagnostic flow-chart based on initial radiological findings of soft-tissue masses (with specific focus on adipocytic soft-tissue tumors [STTs], hemorragic STTs and retroperitoneal STTs) are provided considering relevant results from novel researches, guidelines, and experts' viewpoints, with the aim to help radiologists and clinicians in their practice. Particularly, the central place of sarcoma reference centers in the diagnostic and therapeutic management is highlighted, as well as the pivotal role that radiologists should play to correctly identify patients with soft-tissue sarcoma at the initial stage of the disease. Indications and methods for performing imaging-guided biopsies are also discussed, as well as clues to improve soft-tissue sarcoma grading with conventional and quantitative imaging.

Soft tissue sarcoma: intravoxel incoherent motion and diffusion kurtosis imaging parameters correlate with the histological grade and Ki-67 expression

BACKGROUND

Accurate prediction of the histological grade and Ki-67 expression of soft tissue sarcoma (STS) before surgery is essential for the subsequent diagnosis, treatment, and prognostic evaluation of patients.

PURPOSE

To evaluate intravoxel incoherent motion (IVIM) and diffusion kurtosis imaging (DKI) in predicting the histological grade and Ki-67 expression of STS.

MATERIAL AND METHODS

A total of 40 patients underwent 3-T MRI, including conventional sequences; IVIM and DKI parameters were obtained. All patients were divided into a low-grade (grade 1 and grade 2) group and a high-grade (grade 3) group through pathological analysis. Ki-67 expression of each lesion was calculated. Chi-square test, independent sample t-test, Mann-Whitney U test, Pearson, Spearman, and receiver operating characteristic curve analysis were performed.

RESULTS

There were 17 patients in the low-grade group and 23 in the high-grade group. Ki-67 expression was in the range of 10%-80%. D value was inversely correlated with Ki-67 expression. MK value showed a moderate positive correlation with Ki-67 expression. Regarding histological grading, only the peritumoral enhancement was statistically different between low- and high-grade STS on conventional MRI (P=0.024). The high-grade group had significantly higher MK value and lower D and MD value than the low-grade group. MK value showed the best diagnostic performance. The combination of MK and MD yielded the highest specificity (88.24%), and the combination of D, MK, and MD yielded the best area under the curve value (0.841) and sensitivity (95.65%).

CONCLUSION

IVIM and DKI parameters were correlated with Ki-67 expression and could help differentiate between low- and high-grade STS.

Soft Tissue Sarcomas: The Role of Quantitative MRI in Treatment Response Evaluation

BACKGROUND

Although curative surgery remains the cornerstone of the therapeutic strategy in patients with soft tissue sarcomas (STS), neoadjuvant radiotherapy and chemotherapy (NART and NACT, respectively) are increasingly used to improve operability, surgical margins and patient outcome. The best imaging modality for locoregional assessment of STS is MRI but these tumors are mostly evaluated in a qualitative manner.

OBJECTIVE

After an overview of the current standard of care regarding treatment for patients with locally advanced STS, this review aims to summarize the principles and limitations of (i) the current methods used to evaluate response to neoadjuvant treatment in clinical practice and clinical trials in STS (RECIST 1.1 and modified Choi criteria), (ii) quantitative MRI sequences (i.e., diffusion weighted imaging and dynamic contrast enhanced MRI), and (iii) texture analyses and (delta-) radiomics.

Trabectedin and Radiation Therapy for Cardiac Metastasis From Leiomyosarcoma: A Case Report and Review of the Literature

Leiomyosarcoma (LMS) is one of the most frequent subtypes of soft-tissue sarcomas (STSs). Metastatic spread to the heart in cancer patients carries a poor prognosis and there is no known effective treatment. Cardiac metastases of STSs are very rare. Here we present the case of a 55-year-old patient who underwent surgical resection of a retroperitoneal leiomyosarcoma and then developed widespread metastatic disease, treated with a combination of local treatment and systemic therapy. Three years after surgical resection she presented with a cardiac intraventricular mass, which was treated with radiation therapy, while receiving systemic therapy with trabectedin. Such combination therapy was well-tolerated and effective, allowing a substantial dimensional reduction which is perduring to date, 18 months after diagnosis of cardiac metastasis. Available literature and data point to the feasibility and good tolerability of radiation therapy and trabectedin in metastatic sarcoma, yet this is the first report on the effectiveness of the combination for the treatment of cardiac disease. The extended survival since a metastatic relapse (more than 3 years) is likely the result of integrated systemic and loco-regional treatment, which should be always discussed within the framework of a multiprofessional and multidisciplinary setting.

Visceral angiosarcoma: A nationwide analysis of treatment factors and outcomes

BACKGROUND AND OBJECTIVES

Visceral angiosarcoma is rare and aggressive, accounting for 2% of soft tissue sarcomas. Using a national data set, we examine determinants of outcomes for patients presenting with this rare disease.

METHODS

The 2004-2015 National Cancer Database was queried for patients with visceral angiosarcoma. Trends in treatment and outcomes were examined. Factors affecting overall survival (OS) were assessed with log-rank and Cox regression.

RESULTS

Eight hundred and ninety-three patients with visceral angiosarcoma were identified (median age 65 years, male [63%], Charlson comorbidity index <1 [86%]). Tumor size was <5 cm in 20.7%, and 34.2% were moderate/high grade. Median OS was 3.8 months (95% CI: 3.4-4.4). By multivariate analysis, increased tumor grade and size, and liver/biliary origin demonstrated worse OS while surgery, radiation, and systemic chemotherapy demonstrated improved OS (all p < 0.001). Survival was similar between patients achieving R0 resection and those with R1/2 resection receiving chemotherapy by Kaplan-Meier analysis.

CONCLUSIONS

Visceral angiosarcomas are rare tumors with poor outcomes. Liver/biliary origin, higher tumor grade, and larger tumor size demonstrate worse outcomes. While R0 resection remains the mainstay of treatment, patients with R1/R2 resection have improved survival with addition of chemotherapy. Consideration should be made for multimodal therapy in these patients.

Radiomics of Musculoskeletal Sarcomas: A Narrative Review

Bone and soft-tissue primary malignant tumors or sarcomas are a large, diverse group of mesenchymal-derived malignancies. They represent a model for intra- and intertumoral heterogeneities, making them particularly suitable for radiomics analyses. Radiomic features offer information on cancer phenotype as well as the tumor microenvironment which, combined with other pertinent data such as genomics and proteomics and correlated with outcomes data, can produce accurate, robust, evidence-based, clinical-decision support systems. Our purpose in this narrative review is to offer an overview of radiomics studies dealing with Magnetic Resonance Imaging (MRI)-based radiomics models of bone and soft-tissue sarcomas that could help distinguish different histotypes, low-grade from high-grade sarcomas, predict response to multimodality therapy, and thus better tailor patients’ treatments and finally improve their survivals. Although showing promising results, interobserver segmentation variability, feature reproducibility, and model validation are three main challenges of radiomics that need to be addressed in order to translate radiomics studies to clinical applications. These efforts, together with a better knowledge and application of the “Radiomics Quality Score” and Image Biomarker Standardization Initiative reporting guidelines, could improve the quality of sarcoma radiomics studies and facilitate radiomics towards clinical translation.

The baseline neutrophil lymphocyte ratio predicts survival in soft-tissue sarcoma: A 17-year cohort study

BACKGROUND

Abnormal ratios of peripheral blood cells, e.g. neutrophil-lymphocyte ratio (NLR), are strongly associated with poor outcomes in numerous cancers. In soft-tissue sarcoma (STS), the NLR has been studied in populations outside the UK although many have major methodological flaws, which represents the rationale for this study.

METHODS

Over 17 years old (2002-2019) adults with extremity STS were included. The baseline NLR (at the time of diagnosis) was calculated. The association between NLR, disease recurrence and survival was explored using cubic splines and a threshold of 3 selected, which is in keeping with the literature. Multivariable Cox regression was used to estimate overall survival, disease-free survival and recurrence with Hazard Ratios (HR) and 95% confidence intervals (CI).

RESULTS

Overall, 401 patients were included. The median follow-up was 3 years 8 months (interquartile range 1 years 7 months to 5 years 2 months). During surveillance 148 died (37%), of which 123 (76%) were attributable to sarcoma. At the time of diagnosis, an NLR≥3 was independently associated with worse overall survival (adjusted HR 1.44 [95% 1.01, 2.03]). However, the baseline NLR was not associated with the risk of recurrence (adjusted HR 0.98 [95% CI 0.62, 1.57]) or disease-free survival (adjusted HR 1.11 [95% CI 0.79, 1.56]).

CONCLUSIONS

At the time of diagnosis of STS, the NLR is strongly associated with survival and may serve as a cheap and readily available biomarker to personalise treatment plans for patients.

Implementing a Machine Learning Strategy to Predict Pathologic Response in Patients With Soft Tissue Sarcomas Treated With Neoadjuvant Chemotherapy

PURPOSE

Neoadjuvant chemotherapy (NAC) has been increasingly used in patients with locally advanced high-risk soft tissue sarcomas in the past decade, but definition and prognostic impact of a good histologic response (GHR) are lacking. Our aim was to investigate which histologic feature from the post-NAC surgical specimen independently correlated with metastatic relapse-free survival (MFS) in combination with clinical, radiologic, and pathologic features using a machine learning approach.

METHODS

This retrospective study included 175 consecutive patients (median age: 59 years, 75 women) with resectable disease, treated with anthracycline-based NAC between 1989 and 2015 in our sarcoma reference center, and with quantitative histopathologic analysis of the surgical specimen. The outcome of interest was the MFS. A multimodel, multivariate survival analysis was used to define GHR. The added prognostic value of GHR was investigated through the comparisons with the standard model (including histologic grade, size, and depth) and SARCULATOR nomogram using concordance indices (c-index) and Monte-Carlo cross-validation.

RESULTS

Seventy-two patients (72 of 175, 41.1%) had a metastatic relapse. Stepwise Cox regression, random survival forests, and least absolute shrinkage and selection operator-penalized Cox regression all converged toward the same definition for GHR, ie, < 5% stainable tumor cells. The five-year MFS probability was 1 (95% CI, 1 to 1) in patients with GHR versus 0.73 (95% CI, 0.65 to 0.81) in patients without GHR (log-rank P = .0122). The final prognostic model incorporating the GHR was significantly better than the standard model and SARCULATOR (average c-index in testing sets = 0.72 [95% CI, 0.61 to 0.82] v 0.57 [95% CI, 0.44 to 0.70] and 0.54 [95% CI, 0.45 to 0.64], respectively; P = .0414 and .0091).

CONCLUSION

Histologic response to NAC improves the prediction of MFS in patients with soft tissue sarcoma and represents a possible end point in future studies exploring innovative regimens in the neoadjuvant setting.

Diagnostic accuracy of ultrasound-guided core needle biopsy versus incisional biopsy in soft tissue sarcoma: an institutional experience

Core needle biopsy (CNB) is gaining in importance due to its advantages in the matter of patient morbidity, time and cost. Nevertheless, controversies still exist regarding the biopsy technique of choice for the accurate diagnosis of soft tissue sarcoma (STS). This retrospective cohort study compared the diagnostic performance between ultrasound-guided CNB and incisional biopsy (IB), both performed by orthopedic surgeons. The aims of the study were to answer the following questions: (1) Is ultrasound-guided CNB a highly reliable modality for diagnosing STSs? (2) Is CNB equally useful to IB for identifying histologic subtype? (3) Had patients who underwent CNB a reduced risk of complications? One-hundred and fifty-three patients who underwent resection of soft tissue sarcoma were classified into two groups according to biopsy technique prior to surgery; CNB group (n = 95) and IB group (n = 58). The final surgical specimens were in 40 patients liposarcoma (myxoid, pleomorphic and dedifferentiated), 39 undifferentiated pleomorphic sarcoma (UPS), 33 myxofibrosarcoma, 10 synovial sarcoma, 10 leiomyosarcoma and in the remaining 21 patients different soft tissue sarcoma entities. Sarcoma location of 71 patients was in the thigh, 19 in the lower leg, 22 in the upper arm and shoulder area; 10 in the knee and gluteal region, 9 in the thoracic region, the residual 12 in other body areas. Malignancy was correctly diagnosed in 87% (83 of 95) for the CNB group and 93% (54/58) for the IB group. Correct identification rate of histologic subtype was 80% (76 of 95) in the CNB group and 83% (48 of 58) in the IB group. There were no significant differences in the correct diagnosis rates of malignancy and subtype between the two techniques. No complications were seen in the CNB group, whereas 2 patients in whom IB was performed developed pulmonary embolism and 1 patient surgical site infection. Ultrasound-guided CNB is highly accurate and not inferior to IB in diagnosing the dignity of lesions and histologic subtype in patients with suspected STSs.

Soft tissue sarcoma: can dynamic contrast-enhanced (DCE) MRI be used to predict the histological grade?

OBJECTIVE

To determine if dynamic contrast-enhanced (DCE) magnetic resonance imaging (MRI) parameters reflect histological grade of soft tissue sarcoma (STS) MATERIALS AND METHODS: The medical records of 50 patients diagnosed with pathologically confirmed STS were retrospectively reviewed. Each STS was assessed with conventional contrast-enhanced MRI and DCE-MRI using a 3.0-T MRI system. The conventional MRI characteristics of low-grade (grade 1) and high-grade (grade 2 and grade 3) tumors were analyzed. Semi-quantitative parameters, including iAUC and TTP, and quantitative parameters, including K^trans, K_ep, and V_e, were derived from DCE-MRI. The diagnostic performances and optimal thresholds of various combinations of DCE-MRI parameters for predicting histological grades of STS were investigated using receiver operator characteristic (ROC) curves.

RESULTS

On conventional MRI, high-grade STSs were significantly larger (≥ 5 cm) and more likely to show a heterogeneous signal intensity on T₂WI (> 75%), peritumoral hyperintensity on T₂WI, or tumor necrosis (> 50%) compared with low-grade STS. On DCE-MRI, iAUC, TTP, K^trans, and K_ep were significant predictors of STS histological grade. K^trans had a high diagnostic value for differentiating between high-grade and low-grade STSs. The combination of iAUC, TTP, and K^trans yielded a higher AUC value (0.841) than the other models.

CONCLUSION

High-grade STSs were usually larger than low-grade STSs, had unclear boundaries, a heterogeneous signal intensity on T2-weighted image (T₂WI), and extensive necrosis. On DCE-MRI, iAUC, TTP, K^trans, and K_ep could differentiate between high-grade and low-grade STSs. The combination of iAUC, TTP, and K^trans had a high diagnostic performance for differentiating between STS histological grades.

Soft Tissue Sarcoma: Preoperative MRI-Based Radiomics and Machine Learning May Be Accurate Predictors of Histopathologic Grade

OBJECTIVE. The purpose of this study was to assess the value of radiomics features for differentiating soft tissue sarcomas (STSs) of different histopathologic grades. MATERIALS AND METHODS. The T1-weighted and fat-suppressed T2-weighted MR images of 70 STSs of varying grades (35 low-grade [grades 1 and 2], 35 high-grade [grade 3]) formed the primary dataset used to train multiple machine learning algorithms for the construction of models for assigning STS grade. The models were tested with a separate validation dataset. RESULTS. Different machine learning algorithms had different strengths and weaknesses. The best classification algorithm for the prediction of STS grade had a combination of the least absolute shrinkage and selection operator feature selection method and the random forest classification algorithm (AUC, 0.9216; 95% CI, 0.8437-0.9995) in the validation set. The accuracy of the combined methods applied to the validation set was 91.43%; sensitivity, 88.24%; and specificity, 94.44%. CONCLUSION. Because of tumor heterogeneity, initial biopsy grade may be an underestimate of the final grade identified in extensive histopathologic analysis of surgical specimens. This creates an urgent need to construct an accurate preoperative approach to grading STS. This radiomics study revealed the optimal machine learning approaches for differentiating STS grades. This capability can enhance the precision of preoperative diagnosis.

Neoadjuvant Treatment Options in Soft Tissue Sarcomas

Due to the heterogeneity of soft tissue sarcomas (STS), the choice of the proper perioperative treatment regimen is challenging. Neoadjuvant therapy has attracted increasing attention due to several advantages, particularly in patients with locally advanced disease. The number of available neoadjuvant modalities is growing continuously. We may consider radiotherapy, chemotherapy, targeted therapy, radiosensitizers, hyperthermia, and their combinations. This review discusses possible neoadjuvant treatment options in STS with an emphasis on available evidence, indications for each treatment type, and related risks. Finally, we summarize current recommendations of the STS neoadjuvant therapy response assessment.

Soft tissue sarcomas in the elbow region and influence of their anatomical features in their treatment. Experience in the Unit of Musculoskeletal Tumours

BACKGROUND AND AIM

Soft tissue sarcomas are exceptionally located in the elbow region. The aim of this work was to study the soft tissue sarcomas of the elbow region, their epidemiological and histopathological characteristics, anatomical features, the treatment performed, and the results obtained, in a unit of musculoskeletal tumours.

METHODS

Retrospective review of ten patients with a mean follow-up of 65.0 ± 11.9 (range 21-132) months with soft tissue sarcomas located in the elbow region operated in our centre between 2008 and 2016.

RESULTS

Mean age was 60.8 ± 6.7 years. Undifferentiated pleomorphic sarcoma was the most frequent histological diagnosis. Limb preservation surgery was performed in 90% of patients. Three patients were previously operated without following surgical oncology guidelines in another hospital, and this was statistically related to the need for more than one surgery to control the disease. R1 margin was obtained in 5 patients and R0 in another 5. Adjuvant radiotherapy was used in 7 cases. In 4 patients, subsequent surgery was performed for local or systemic control of the disease. Local recurrence occurred in 3 cases and in 5 there was distant disease.

CONCLUSION

The elbow region presents difficulty in achieving wide margins due to the proximity of neurovascular structures, adjuvant and / or neoadjuvant therapies could play an important role in performing limb preservation surgery. It would be advisable to refer these tumours to specialized units with multidisciplinary teams.

Core needle biopsy versus incisional biopsy for differentiation of soft-tissue sarcomas: A systematic review and meta-analysis

BACKGROUND

Controversies exist regarding the biopsy technique of choice for the accurate diagnosis of soft-tissue sarcoma (STS). The objective of this systematic review and meta-analysis was to compare the diagnostic accuracy of core needle biopsy (CNB) versus incisional biopsy (IB) in STS with reference to the final histopathological result.

METHODS

Studies regarding the diagnostic accuracy of CNB and IB in detecting STS were searched systematically in the MEDLINE and EMBASE databases. Estimates of sensitivity and specificity with associated 95% CIs for diagnostic accuracy were calculated. The risk of bias was assessed using the Quality Assessment of Diagnostic Accuracy Studies version 2 (QUADAS-2).

RESULTS

A total of 17 studies comprising 2680 patients who underwent 1582 CNBs and 241 IBs with subsequent tumor resection met the inclusion criteria. The sensitivity and specificity of CNB and IB to detect the dignity of lesions were 97% (95% CI, 95%-98%) and 99% (95% CI, 97%-99%), respectively, and 96% (95% CI, 92%-99%) and 100% (95% CI, 94%-100%), respectively. Estimates of the sensitivity and specificity of CNB and IB to detect the STS histotype were 88% (95% CI, 86%-90%) and 77% (95% CI, 72%-81%), respectively, and 93% (95% CI, 87%-97%) and 65% (95% CI, 49%-78%), respectively. Patients who underwent CNB had a significantly reduced risk of complications compared with patients who underwent IB (risk ratio, 0.14; 95% CI, 0.03-0.56 [P ≤ .01). Quality assessment of studies revealed a high risk of bias.

CONCLUSIONS

CNB has high accuracy in diagnosing the dignity of lesions and STS histotype in patients with suspected STS with fewer complications compared with IB. Therefore, CNB should be regarded as the primary biopsy technique.

T2 -based MRI Delta-radiomics improve response prediction in soft-tissue sarcomas treated by neoadjuvant chemotherapy

BACKGROUND

Standard of care for patients with high-grade soft-tissue sarcoma (STS) are being redefined since neoadjuvant chemotherapy (NAC) has demonstrated a positive effect on patients' outcome. Yet response evaluation in clinical trials still relies on RECIST criteria.

PURPOSE

To investigate the added value of a Delta-radiomics approach for early response prediction in patients with STS undergoing NAC.

STUDY TYPE

Retrospective.

POPULATION

Sixty-five adult patients with newly-diagnosed, locally-advanced, histologically proven high-grade STS of trunk and extremities. All were treated by anthracycline-based NAC followed by surgery and had available MRI at baseline and after two chemotherapy cycles.

FIELD STRENGTH/SEQUENCE

Pre- and postcontrast enhanced T₁ -weighted imaging (T₁ -WI), turbo spin echo T₂ -WI at 1.5 T.

ASSESSMENT

A threshold of <10% viable cells on surgical specimens defined good response (Good-HR). Two senior radiologists performed a semantic analysis of the MRI. After 3D manual segmentation of tumors at baseline and early evaluation, and standardization of voxel-sizes and intensities, absolute changes in 33 texture and shape features were calculated.

STATISTICAL TESTS

Classification models based on logistic regression, support vector machine, k-nearest neighbors, and random forests were elaborated using crossvalidation (training and validation) on 50 patients ("training cohort") and was validated on 15 other patients ("test cohort").

RESULTS

Sixteen patients were good-HR. Neither RECIST status (P = 0.112) nor semantic radiological variables were associated with response (range of P-values: 0.134-0.490) except an edema decrease (P = 0.003), although 14 shape and texture features were (range of P-values: 0.002-0.037). On the training cohort, the highest diagnostic performances were obtained with random forests built on three features: Δ_Histogram_Entropy, Δ_Elongation, Δ_Surrounding_Edema, which provided: area under the curve the receiver operating characteristic = 0.86, accuracy = 88.1%, sensitivity = 94.1%, and specificity = 66.3%. On the test cohort, this model provided an accuracy of 74.6% but 3/5 good-HR were systematically ill-classified.

DATA CONCLUSION

A T₂ -based Delta-radiomics approach might improve early response assessment in STS patients with a limited number of features.

LEVEL OF EVIDENCE

3 Technical Efficacy: Stage 2 J. Magn. Reson. Imaging 2019;50:497-510.

Neoadjuvant Trabectedin plus Radiotherapy in High-Grade Sarcoma of the Leg: A Case Report

Here, we present the case of a 78-year-old male patient with undifferentiated spindle cell sarcoma on the posteromedial surface of the right leg who experienced a long-lasting progression-free survival. Due to an underlying cardiac disease, the patient was not suitable for anthracyclines. In September 2015, he received first-line chemotherapy with trabectedin (Yondelis®) at the approved dosage and regimen - concomitant with external radiotherapy (RT). After the first 9 cycles of trabectedin plus RT given in the neoadjuvant setting, the patient underwent surgical resection. At that stage, we observed a very good pathological response with 80% of necrotic area. The patient resumed the therapy with trabectedin; however, approximately 5 months later, we observed a new nodular heterogeneous lesion with ill-defined margins in the right leg and suggestive of tumor relapse. Subsequently an above-the-knee amputation was performed, and the patient resumed his trabectedin therapy with the same dosage and regimen. In January 2018, almost 2 1/2 years after the start of trabectedin treatment and 30+ cycles of trabectedin, the patient is locoregionally and distant metastatically disease-free. Currently, the treatment with trabectedin is maintained without any significant serious toxicity. Future clinical trials are needed to gain additional insights into the role of trabectedin maintenance therapy until disease progression in the neoadjuvant setting and to identify predictive and prognostic criteria for response to trabectedin in patients with advanced sarcoma.

Volume of interest delineation techniques for 18F-FDG PET-CT scans during neoadjuvant extremity soft tissue sarcoma treatment in adults: a feasibility study

BACKGROUND

This study explores various volume of interest (VOI) delineation techniques for fluorine-18-fluorodeoxyglucose positron emission tomography with computed tomography (18F-FDG PET-CT) scans during neoadjuvant extremity soft tissue sarcoma (ESTS) treatment.

RESULTS

During neoadjuvant treatment, hyperthermic isolated limb perfusion (HILP) and preoperative external beam radiotherapy (EBRT), 11 patients underwent three 18F-FDG PET-CT scans. The first scan was made prior to the HILP, the second after the HILP but prior to the start of the EBRT, and the third prior to surgical resection. An automatically drawn VOIauto, a manually drawn VOIman, and two gradient-based semi-automatically drawn VOIs (VOIgrad and VOIgrad+) were obtained. Maximum standardized uptake value (SUVmax), SUVpeak, SUVmean, metabolically active tumor volume (MATV), and total lesion glycolysis (TLG) were calculated from each VOI. The correlation and level of agreement between VOI delineation techniques was explored. Lastly, the changes in metabolic tumor activity were related to the histopathologic response. The strongest correlation and an acceptable level of agreement was found between the VOIman and the VOIgrad+ delineation techniques. A decline (VOIman) in SUVmax, SUVpeak, SUVmean, TLG, and MATV (all p < 0.05) was found between the three scans. A > 75% decline in TLG between scan 1 and scan 3 possibly identifies histopathologic response.

CONCLUSIONS

The VOIgrad+ delineation technique was identified as most reliable considering reproducibility when compared with the other VOI delineation techniques during the multimodality neoadjuvant treatment of locally advanced ESTS. A significant decline in metabolic tumor activity during the treatment was found. TLG deserves further exploration as predictor for histopathologic response after multimodality ESTS treatment.

Adjuvant chemotherapy-Radiotherapy-Chemotherapy sandwich protocol in resectable soft tissue sarcoma: An updated single-center analysis of 104 cases

Adjuvant therapy of local soft tissue sarcomas (STS) after wide surgical excision still is a topic under controversial scientific debate. In this single center report we have offered an adjuvant “sandwich” therapy protocol consisting of 4 cycles of doxorubicin (75 mg/m² i.v. over 1 h on day 1) followed by ifosfamide (5 g/m² i.v. over 24 h starting on day 1) and local radiotherapy scheduled between chemotherapy cycles 2 and 3 to 104 consecutive patients after wide surgical excision (R0) of histologically proven high-grade STS. After a mean follow-up of 39 months (range 5–194 months) relapse free survival (RFS) at 2 and 5 years was 68.1% (95% CI, 58.5–77.7%) and 61.2% (95% CI, 50.4–71.6%). When analyzing the 82 STS cases of the extremities only 2- and 5-year RFS was 74.0% (95% CI, 64.0–84.0%) and 65.3% (95% CI, 53.7–76.9%). By intent-to-treat analysis, the overall survival (OS) at 2 years was 87.3% (95% CI, 80.5–94.1%) and 75.6% (95% CI, 65.2–86.0%) at 5 years, while OS for STS of the extremities only cohort was 90.5% (95% CI, 83.7–97.3%) and 79.0% (95% CI, 68.4–89.6%), respectively. Tolerability of the treatment was good. This analysis demonstrates the feasibility of adjuvant chemoradiotherapy and reflects the results of the long lasting intensive multidisciplinary team approach at our “high-volume” sarcoma center. The long-term survival in our patients is among the highest reported and the low local and distant recurrence rate in high-risk STS is at least comparable to the published data.

Histopathological tumor response following neoadjuvant hyperthermic isolated limb perfusion in extremity soft tissue sarcomas: Evaluation of the EORTC-STBSG response score

INTRODUCTION

This study aims to evaluate the applicability and prognostic value of the European Organization for Research and Treatment of Cancer-Soft Tissue and Bone Sarcoma Group (EORTC-STBSG) histopathological response score in extremity soft tissue sarcoma (ESTS) patients treated with neoadjuvant hyperthermic isolated limb perfusion (HILP) and delayed surgical resection.

METHODS

Patients treated between 1991 and 2016 were included. The histopathological tumor response was established in accordance with the EORTC-STBSG response score. The distribution of patients was assorted according to the 5-tier histopathological response score for tumor grade, histological subtype and HILP regimen. Predictors for local recurrence free survival (LRFS) and overall survival (OS) were identified through Kaplan-Meier and Cox regression analyses.

RESULTS

Ninety-one patients were included and their resection specimens were reanalyzed. Which resulted in 11 Grade A (12.1%), ten Grade B (11.0%), 15 Grade C (16.5%), 22 Grade D (24.2%) and 33 Grade E (36.3%) responses found among the series. The histopathological response was significantly influenced by the HILP regimen used, p = 0.033. Median follow-up was 65.0 (18.0-157.0) months. The histopathological response was not associated with LRFS nor OS. Resection margins, HILP regimen and adjuvant radiotherapy were associated with LRFS. Patients' age, tumor grade, tumor size and histological subtype were predictors for OS.

CONCLUSIONS

The EORTC-STBSG response score is applicable for determining the histopathological response to neoadjuvant ESTS treatment. However, this response does not seem to predict LRFS nor OS in locally advanced ESTS.

Soft tissue sarcomas: new opportunity of treatment with PARP inhibitors?

BACKGROUND

Poly(ADP-ribose) polymerases (PARP) are a large family of enzymes involved in several cellular processes, including DNA single-strand break repair via the base-excision repair pathway. PARP inhibitors exert antitumor activity by both catalytic PARP inhibition and PARP-DNA trapping, moreover PARP inhibition represents a potential synthetic lethal approach against cancers with specific DNA-repair defects. Soft tissue sarcoma (STSs) are a heterogeneous group of mesenchymal tumors with locally destructive growth, high risk of recurrence and distant metastasis.

OBJECTIVES

The purpuse of this review is to provide an overview of the main preclinical and clinical data on use of PARPi in STSs and of effect and safety of combination of PARPi with irradiation.

RESULTS

Due to numerous genomic alterations in STSs, the DNA damage response pathway can offer an interesting target for biologic therapy. Preclinical and clinical studies showed promising results, with the most robust evidences of PARPi efficacy obtained on Ewing sarcoma bearing EWS-FLI1 or EWS-ERG genomic fusions. The activity of PARP inhibitors resulted potentiated by chemotherapy and radiation. Although mechanisms of synergisms are not completely known, combination of radiation therapy and PARP inhibitors exerts antitumor effect by accumulation of unrepaired DNA damage, arrest in G2/M, activity both on oxic and hypoxic cells, reoxygenation by effect on vessels and promotion of senescence. Early trials have shown a good tolerance profile.

CONCLUSIONS

The use of PARP inhibitors in advanced stage STSs, alone or combined in multimodal treatments, is of great interest and warrants further investigations.

Systemic Treatment for Adults with Synovial Sarcoma

OPINION STATEMENT

Synovial sarcoma (SS) is a rare, yet highly malignant, type of soft tissue sarcoma (STS), for which survival has not improved significantly during the past years. In this review, we focus on systemic treatment in adults. Compared to other STS, SS are relatively chemosensitive. Ifosfamide and ifosfamide combinations are active in different lines of treatment. In high-risk extremity and chest wall STS, neoadjuvant doxorubicin and ifosfamide has shown as much activity as high-dose ifosfamide. There are indications that combination chemotherapy with doxorubicin and ifosfamide in this setting improves outcome. In the first-line metastatic setting, combination treatment with doxorubicin and ifosfamide is a preferred option in fit patients, while in other patients, sequential doxorubicin and ifosfamide can be considered. In second and later lines, pazopanib and trabectedin have shown activity. Many new approaches to treat metastatic SS are currently under investigation, both preclinical as well as clinical, including other receptor tyrosine kinase inhibitors, epigenetic modulators, compounds interfering with DNA damage response (DDR), and immunotherapy.

Primary Culture of Undifferentiated Pleomorphic Sarcoma: Molecular Characterization and Response to Anticancer Agents

Undifferentiated pleomorphic sarcoma (UPS) is an aggressive mesenchymal neoplasm with no specific line of differentiation. Eribulin, a novel synthetic microtubule inhibitor, has shown anticancer activity in several tumors, including soft tissue sarcomas (STS). We investigated the molecular biology of UPS, and the mechanisms of action of this innovative microtubule-depolymerizing drug. A primary culture from a patient with UPS was established and characterized in terms of gene expression. The activity of eribulin was also compared with that of other drugs currently used for STS treatment, including trabectedin. Finally, Western blot analysis was performed to better elucidate the activity of eribulin. Our results showed an upregulation of epithelial mesenchymal transition-related genes, and a downregulation of epithelial markers. Furthermore, genes involved in chemoresistance were upregulated. Pharmacological analysis confirmed limited sensitivity to chemotherapy. Interestingly, eribulin exhibited a similar activity to that of standard treatments. Molecular analysis revealed the expression of cell cycle arrest-related and pro-apoptotic-related proteins. These findings are suggestive of aggressive behavior in UPS. Furthermore, the identification of chemoresistance-related genes could facilitate the development of innovative drugs to improve patient outcome. Overall, the results from the present study furnish a rationale for elucidating the role of eribulin for the treatment of UPS.

Pre- and Postoperative Chemotherapy in Localized Extremity Soft Tissue Sarcoma: A European Organization for Research and Treatment of Cancer Expert Survey

BACKGROUND

The management of localized extremity soft tissue sarcomas (STS) is challenging and the role of pre- and postoperative chemotherapy is unclear and debated among experts.

MATERIALS AND METHODS

Medical oncology experts of the European Organization for Research and Treatment of Cancer Soft Tissue and Bone Sarcoma Group were asked to participate in this survey on the use of pre- and postoperative chemotherapy in STS. Experts from 12 centers in Belgium, France, Germany, Great Britain, Italy, Switzerland, and The Netherlands agreed to participate and provided their treatment algorithm. Answers were converted into decision trees based on the objective consensus methodology. The decision trees were used as a basis to identify consensus and discrepancies.

RESULTS

Several criteria used for decision-making in extremity STS were identified: chemosensitivity, fitness, grading, location, and size. In addition, resectability and resection status were relevant in the pre- and postoperative setting, respectively. Preoperative chemotherapy is considered in most centers for marginally resectable tumors only. Yet, in some centers, neoadjuvant chemotherapy is used routinely and partially combined with hyperthermia. Although most centers do not recommend postoperative chemotherapy, some offer this treatment on a regular basis. Radiotherapy is an undisputed treatment modality in extremity STS.

CONCLUSION

Due to lacking evidence on the utility of pre- and postoperative chemotherapy in localized extremity STS, treatment strategies vary considerably among European experts. The majority recommended neoadjuvant chemotherapy for marginally resectable grade 2-3 tumors; the majority did not recommend postoperative chemotherapy in any setting.

IMPLICATIONS FOR PRACTICE

The management of localized extremity soft tissue sarcomas (STS) is challenging and the role of pre- and postoperative chemotherapy is unclear and debated among experts. This study analyzed the decision-making process among 12 European experts on systemic therapy for STS. A wide range of recommendations among experts regarding the use of perioperative chemotherapy was discovered. Discrepancies in the use of decision criteria were also uncovered, including the definition of what constitutes high-risk cancer, which is a basis for many to recommend chemotherapy. Before any standardization is possible, a common use of decision criteria is necessary.

High-grade myxofibrosarcoma of the abdominal wall

The authors present a case of a 57-year-old man, who presented to the surgical clinic with a mass in the suprapubic region. A CT scan revealed a well-circumscribed lobular, heterogeneous soft tissue mass measuring 12×8.6×7.8 cm. The final histopathological diagnosis from the resection of the lesion was a myxofibrosarcoma (MFS), grade 3. The management of MFS includes surgical and oncological options which are reviewed here. These are aimed at complete excision and reducing the risk of local occurrence.

Neoadjuvant chemotherapy in soft tissue sarcomas: latest evidence and clinical implications

Soft tissue sarcomas are a rare and multifaceted group of solid tumours. Neoadjuvant chemotherapy is increasingly used to limit loss of function after wide surgical excision with the ultimate aim of improving patient survival. Recently, advances in the identification of effective treatment strategies and improvements in patient risk stratification have been reached. A randomized trial demonstrated that neoadjuvant epirubicin and ifosfamide improves survival of patients affected by five high-risk soft tissue sarcoma histologies of trunk and extremities, including undifferentiated pleomorphic sarcoma, myxoid liposarcoma, synovial sarcoma, malignant peripheral nerve sheath tumours, and leiomyosarcoma. Selection of patients for these treatments is expected to be improved by the eighth edition of the American Joint Committee on Cancer (AJCC) TNM staging system, as it tailors T-stage categories on primary tumour site and considers a prognostic nomogram for retroperitoneal sarcoma, which also includes soft tissue sarcoma histology and other patient and tumour features not directly included in the TNM staging. Within this framework, this article will present neoadjuvant treatment strategies for high-risk soft tissue sarcoma, emphasizing the most recent advances and discussing the need for further research to improve the effectiveness of neoadjuvant treatments.

Malignant solitary fibrous tumor in retroperitoneum: A case report and literature review

RATIONALE

Solitary fibrous tumor (SFT) is a rare mesenchymal tumor occurs in various sites. Malignant SFT in retroperitoneum is extremely rare.

PATIENT CONCERNS

We report a case of malignant retroperitoneal SFT in a 59-year-old man presented with right flank pain for 1 month.

DIAGNOSES, INTERVENTIONS AND OUTCOMES

A laparotomy and resection of the tumor were performed, the histopathologic and immunohistochemical findings were consistent with malignant retroperitoneal SFT. No adjuvant treatment was performed, and the patient had no signs of recurrence or metastasis at the 12 months follow-up.

LESSONS

Complete surgical excision is the basic treatment principle for malignant retroperitoneal SFT. The histologic features and the Ki-67 label index are helpful for the diagnosis of malignant SFT.