Soft tissue sarcomas

Low-Grade Malignant Peripheral Nerve Sheath Tumor: A Case Report of Exceptional Parapatellar Location in the Knee

Malignant tumors of the peripheral nerve sheaths are uncommon, constituting a small percentage, typically ranging from 2% to 5% of soft tissue sarcomas. Etiological diagnosis is often difficult but is guided by imaging and confirmed by histopathological and immunohistochemical examination. We report a case of a 46-year-old woman admitted for management of a mass in the medial parapatellar region of the right knee. Her medical history included a burn to the right leg five years ago and a previously undocumented resection of a medial parapatellar tissue mass in the right knee. Radiological examination showed a deep and superficial soft tissue mass in the medial soft tissue of the right knee opposite the patella, with no hemorrhagic components and heterogeneous enhancement after injection of gadolinium. Histopathology confirmed the diagnosis of a low-grade peripheral nerve sheath tumor, and a thoracic-abdominal-pelvic CT scan was performed, which was normal. Treatment consisted of a simple carcinological resection and local radiotherapy. No local recurrence was noted after one year of follow-up.

The Impact of Edema on MRI Radiomics for the Prediction of Lung Metastasis in Soft Tissue Sarcoma

INTRODUCTION

This study aimed to evaluate whether radiomic features extracted solely from the edema of soft tissue sarcomas (STS) could predict the occurrence of lung metastasis in comparison with features extracted solely from the tumoral mass.

MATERIALS AND METHODS

We retrospectively analyzed magnetic resonance imaging (MRI) scans of 32 STSs, including 14 with lung metastasis and 18 without. A segmentation of the tumor mass and edema was assessed for each MRI examination. A total of 107 radiomic features were extracted for each mass segmentation and 107 radiomic features for each edema segmentation. A two-step feature selection process was applied. Two predictive features for the development of lung metastasis were selected from the mass-related features, as well as two predictive features from the edema-related features. Two Random Forest models were created based on these selected features; 100 random subsampling runs were performed. Key performance metrics, including accuracy and area under the ROC curve (AUC), were calculated, and the resulting accuracies were compared.

RESULTS

The model based on mass-related features achieved a median accuracy of 0.83 and a median AUC of 0.88, while the model based on edema-related features achieved a median accuracy of 0.75 and a median AUC of 0.79. A statistical analysis comparing the accuracies of the two models revealed no significant difference.

CONCLUSION

Both models showed promise in predicting the occurrence of lung metastasis in soft tissue sarcomas. These findings suggest that radiomic analysis of edema features can provide valuable insights into the prediction of lung metastasis in soft tissue sarcomas.

Analysis of treatment sequence and outcomes in patients with relapsed malignant peripheral nerve sheath tumors

Background

Malignant peripheral nerve sheath tumors (MPNST) are aggressive soft tissue sarcomas originating from cellular components within the nerve sheath. The incidence of MPNST is highest in people with neurofibromatosis type 1 (NF1), and MPNST is the leading cause of death for these individuals. Complete surgical resection is the only curative therapeutic option, but is often unfeasible due to tumor location, size, or presence of metastases. Evidence-based choices of chemotherapy for recurrent/refractory MPNST remain elusive. To address this gap, we conducted a retrospective analysis of our institutional experience in treating patients with relapsed MPNST in order to describe patient outcomes related to salvage regimens.

Methods

We conducted a retrospective electronic health record analysis of patients with MPNST who were treated at Johns Hopkins Hospital from January 2010 to June 2021. We calculated time to progression (TTP) based on salvage chemotherapy regimens.

Results

Sixty-five patients were included in the analysis. Upfront therapy included single or combined modalities of surgery, chemotherapy, or radiotherapy. Forty-eight patients received at least 1 line of chemotherapy, which included 23 different regimens (excluding active clinical studies). Most patients (n = 42, 87.5%) received a combination of doxorubicin, ifosfamide, or etoposide as first-line chemotherapy. Salvage chemotherapy regimens and their TTP varied greatly, with irinotecan/temozolomide-based regimens having the longest average TTP (255.5 days, among 4 patients).

Conclusions

Patients with advanced or metastatic MPNST often succumb to their disease despite multiple lines of therapy. These data may be used as comparative information in decision-making for future patients and clinical trials.

Analysis of Clinical Outcomes of Patients with Soft Tissue Sarcoma

The aim of this study was to evaluate the outcome of patients with soft tissue sarcoma of the extremity and abdominal wall. This is the retrospective analysis of patients from a prospectively maintained data base from a single institute. We identified 79 patients with intermediate- to high-grade soft tissue sarcomas who were treated at our institute between Jan 2015 and July 2018. Low-grade tumors were excluded. There were 60 males and 19 females with a mean age of 44.6 years. Of the 79 sarcomas, 50 were in the lower limb and 24 in the upper limb and 5 were in abdominal wall. The commonest subtypes were undifferentiated pleomorphic sarcoma (n = 21) and synovial sarcoma (n = 19). Only 9 patients had metastatic disease at presentation. All 79 patients underwent surgical resection with an intent to achieve clear margins. Amputation was done in 19 patients while wide excision of the tumor was done in 60 patients. Adjuvant radiotherapy was given in 49 patients while adjuvant chemotherapy was given in 35 patients. At last follow-up (73 patients), 48 patients are alive without disease, 9 are alive with disease, 12 patients had died of disease, and 4 patients died due to other causes. Overall survival (OS) for 3 year is 77.6%, and estimated mean survival is 55.05 months. Relapse-free surviva (RFS)l at 3 year is 74.3%, and estimated mean RFS is 51.78. The only independent factor that affected the OS was the dimension of primary tumor (p = 0.02). For disease-free survival, the independent factors that affected outcome were stage at presentation (p = 0.04) and dimension of the tumor (p = 0.04). Short-term results shown by this study shows good outcome in patient with intermediate- to high-grade sarcomas when multidisciplinary approach is utilized for the management. Patients who had metastatic disease at presentation did worse than patients who did not.

Deep Learning Radiomics Nomogram to Predict Lung Metastasis in Soft-Tissue Sarcoma: A Multi-Center Study

Objectives

To build and evaluate a deep learning radiomics nomogram (DLRN) for preoperative prediction of lung metastasis (LM) status in patients with soft tissue sarcoma (STS).

Methods

In total, 242 patients with STS (training set, n=116; external validation set, n=126) who underwent magnetic resonance imaging were retrospectively enrolled in this study. We identified independent predictors for LM-status and evaluated their performance. The minimum redundancy maximum relevance (mRMR) method and least absolute shrinkage and selection operator (LASSO) algorithm were adopted to screen radiomics features. Logistic regression, decision tree, random forest, support vector machine (SVM), and adaptive boosting classifiers were compared for their ability to predict LM. To overcome the imbalanced distribution of the LM data, we retrained each machine-learning classifier using the synthetic minority over-sampling technique (SMOTE). A DLRN combining the independent clinical predictors with the best performing radiomics prediction signature (mRMR+LASSO+SVM+SMOTE) was established. Area under the receiver operating characteristics curve (AUC), calibration curves, and decision curve analysis (DCA) were used to assess the performance and clinical applicability of the models.

Result

Comparisons of the AUC values applied to the external validation set revealed that the DLRN model (AUC=0.833) showed better prediction performance than the clinical model (AUC=0.664) and radiomics model (AUC=0.799). The calibration curves indicated good calibration efficiency and the DCA showed the DLRN model to have greater clinical applicability than the other two models.

Conclusion

The DLRN was shown to be an accurate and efficient tool for LM-status prediction in STS.

Pembrolizumab Achieves a Complete Response in an NF-1 Mutated, PD-L1 Positive Malignant Peripheral Nerve Sheath Tumor: A Case Report and Review of the Benchmarks

Malignant peripheral nerve sheath tumors (MPNSTs) represent a rare subtype of neural crest cell-derived soft tissue sarcomas (STS). Standard of care therapy comprises surgical resection followed by adjuvant radiation, and most clinical studies have demonstrated finite survival benefit of radiation and chemotherapy. In metastatic disease, palliative chemotherapy provides very limited efficacy. We report a 60-year-old male patient with a primary para vertebral tumor at T7-T8 with lung metastases who recurred after surgical resection and later progressed on epirubicin plus ifosfamide. He was an international patient and referred to the phase 1 clinic. Molecular profiling and immunohistochemistry of the tumor revealed a PD-L1 expression of 70% (2+) and pathogenic genetic alterations by next-generation sequencing in ARID1A, CDKN2A, KMT2A, NF1, and TP53. Immune checkpoint therapy (ICT) with pembrolizumab was commenced, and interval computed tomography revealed a complete remission by cycle 6. Randomized clinical trials illustrate that ICTs such as anti-PD-1 and anti-CTLA4 monoclonal antibodies in STS cohorts display low or modest response rates by variable PD-L1 expression. This and 3 other case reports of disparate PD-L1 expression demonstrate complete responses in PD-L1 positive MPNSTs treated with ICT. These case reports necessitate further study of ICT in neural crest cell subtype of STS.

Adult Soft-Tissue Sarcomas of the Extremities

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Soft-tissue sarcomas (STS) in adults comprise a heterogeneous group of tumors of mesenchymal origin that share similar biological patterns of local tumor growth and metastatic dissemination.

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The judicious use of imaging studies, biopsy techniques, and pathological evaluations is essential for accurate diagnosis and for planning treatment strategy.

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Wide local resection and radiation therapy form the cornerstone of management of high-grade STS. The role of adjuvant radiation therapy is questionable in the management of small (≤5 cm) superficial lesions that can be resected with negative margins. Chemotherapy given to patients who have nonmetastatic, high-grade STS results in varying benefit in terms of local tumor control and overall survival.

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Coordinated care by a multidisciplinary team of trained surgeons, medical oncologists, radiologists, radiation oncologists, and pathologists has been documented to improve local tumor control and the overall survival of patients with STS.

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Although considerable progress in tumor diagnostics and targeted therapies has been made over the past 2 decades, recommendations and controversies relating to tumor imaging and margins of resection have not changed.

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.

Non-surgical Treatments for Lung Metastases in Patients with Soft Tissue Sarcoma: Stereotactic Body Radiation Therapy (SBRT) and Radiofrequency Ablation (RFA)

BACKGROUND

Radio-frequency ablation (RFA) and Stereotactic Body Radiation Therapy (SBRT) are two emerging therapies for lung metastases.

INTRODUCTION

Aliterature review was performed to evaluate the outcomes and complications of these procedures in patients with lung metastases from soft tissue sarcoma (STS).

METHODS

After selection, seven studies were included for each treatment encompassing a total of 424 patients: 218 in the SBRT group and 206 in the RFA group.

RESULTS

The mean age ranged from 47.9 to 64 years in the SBRT group and from 48 to 62.7 years in the RFA group. The most common histologic subtype was, in both groups, leiomyosarcoma. In the SBRT group, median overall survival ranged from 25.2 to 69 months and median disease- free interval was from 8.4 to 45 months. Two out of seven studies reported G3 and one G3 toxicity, respectively. In RFA patients, overall survival ranged from 15 to 50 months. The most frequent complication was pneumothorax. Local control showed a high percentage for both procedures.

CONCLUSION

SBRT is recommended in patients unsuitable to surgery, in synchronous bilateral pulmonary metastases, in case of deep lesions and patients receiving high-risk systemic therapies. RFA is indicated in case of a long disease-free interval, in oligometastatic disease, when only the lung is involved, in small size lesions far from large vessels. Further large randomized studies are necessary to establish whether these treatments may also represent a reliable alternative to surgery.

Systemic Options for Malignant Peripheral Nerve Sheath Tumors

OPINION STATEMENT

Malignant peripheral nerve sheath tumors (MPNSTs) are rare mesenchymal neoplasms that represent a profound therapeutic challenge due to their high proclivity for recurrence and metastasis and relatively poor response to systemic therapy regimens. While our understanding of the pathophysiology of MPNST is growing, including loss of the tumor suppressor gene neurofibromin and subsequent activation of the Ras pathway, targeted therapy to modify the poor prognosis seen in MPNST patients has thus far been without success. Correspondingly, MPNST patients are treated as per soft tissue sarcoma treatment algorithms with anthracycline-based therapy as the front-line therapy of choice for patients with unresectable, locally advanced, or metastatic MPNST. Beyond first-line anthracycline-based therapy, other standard cytotoxic chemotherapy agents used in advanced MPNST include the alkylating agent ifosfamide and the topoisomerase II inhibitor etoposide. Notably, soft tissue sarcoma regimens are used in MPNST despite distinct systemic therapy sensitivity and prognosis. This is particularly notable for neurofibromatosis type 1 (NF1)-associated MPNST, which is associated with poorer response to systemic therapy and prognosis than sporadic MPNST. As such, NF1-associated MPNST is a particular area in need of novel therapeutic strategies. Given the lack of benefit in the targeting of unique aspects of MPNST disease biology thus far, pre-clinical studies to identify novel rational therapies are critical to inform future clinical trials.

Vaginal epithelioid malignant peripheral nerve sheath tumor nearly misdiagnosed as advanced cervical cancer: A case report

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Vaginal schwannoma.

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Vaginal epithelioid MPNST.

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Malignant peripheral nerve sheath tumors.

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Vaginal cancer.

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Spindle-to-epithelioid tumor.

A 56-year-old woman was referred to our hospital with a pathological diagnosis of squamous cell carcinoma of the cervix. We performed a re-biopsy of the vaginal mass and cervical conization. The mass was originally reported as an epithelioid MPNST after re-biopsy. Strong diffuse S-100 positivity, epithelioid morphology of the lesion, and negativity to all other immune histochemical markers confirmed the diagnosis of epithelioid MPNST. Cervical conization specimen was negative for any neoplasms.

Correlative study of epigenetic regulation of tumor microenvironment in spindle cell melanomas and cutaneous malignant peripheral nerve sheath tumors

The tumor microenvironment (TME) plays critical roles in tumor growth and progression, however key regulators of gene expression in the TME of cutaneous malignant peripheral nerve sheath tumor (C-MPNST) and spindle cell melanoma (SCM) have not been well elucidated. Herein, we investigate the epigenetic regulation of promoters and gene bodies and their effect on the TME composition of C-MPNSTs and SCMs. A cohort of 30 patients was analyzed using differential gene expression (DGE) and gene set enrichment analysis (GSEA) using the Nanostring platform. Methylation analysis was carried out utilizing an Infinium Methylation EPIC array targeting 866,562 methylation site (CpG) islands. DGE revealed overexpression of genes related to mast cells in the TME of SCMs, and a predominance of exhausted CD8⁺ T cells and macrophages in the TME of C-MPNSTs. Interestingly, we further observed promoter hypermethylation in key overexpressed genes and corresponding gene body hypomethylation. Analysis using ENCODE ChIP-sequencing data identified CTCF as the common transcription factor at the site of the hypomethylated probe. These findings support that the TME composition of C-MPNSTs and SCMs is at least partially independent on promoter methylation status, suggesting a possible relationship between gene body enhancers and expression of key TME genes in both entities.

Preoperative lymphocyte count in relation to sarcoma prognosis

PURPOSE

Inflammation plays a major role in tumour development, progression and metastasis. Multiple inflammatory markers such as absolute lymphocyte count, neutrophil-lymphocyte ratio (NLR), lymphocyte-monocyte ratio (LMR) and platelet-lymphocyte ratio have been discovered as prognostic markers for various malignancies. We investigate preoperative lymphocyte count and other cell count ratios and their relation to survival and prognosis of sarcoma patients after surgery.

METHODS

A total of 142 patients from the Orthopaedics Oncology Database were included into this retrospective study. Kaplan-Meier curve and multivariate Cox proportional models were used to calculate the overall survival of patients with sarcoma who underwent radical excision surgery.

RESULTS

High preoperative LMR is significantly associated with better overall survival and prognosis in sarcoma patients, whereas high preoperative NLR is significantly associated with shorter overall survival and poorer prognosis. Multivariate analysis shows that LMR and NLR are good predictors for overall survival at 3 and 5 years after surgery, respectively. Patients with high preoperative lymphocytes count are associated with longer overall survival, but this association is not statistically significant. Our findings suggest that preoperative NLR and LMR are good predictive markers for survival of sarcoma patients.

CONCLUSION

LMR and NLR can be used to identify patients at risk for poor clinical outcome, so that a more aggressive course of treatment can be applied to improve outcome. These are cost-effective prognostic tools as they are calculated from routine preoperative peripheral blood counts. In conclusion, preoperative NLR and LMR are good prognostic markers for predicting the clinical outcome of patients with sarcoma.

Contrast Enhanced Endoscopic Ultrasound Imaging for Gastrointestinal Subepithelial Tumors

Subepithelial tumors are divided into benign subepithelial and potentially malignant gastrointestinal stromal tumors. It is difficult to distinguish between these tumor types. Contrast-enhanced harmonic endoscopic ultrasound is reportedly useful for diagnosing subepithelial tumors, can be safely and easily performed by understanding the principle and method, and can be used to distinguish between tumor types with high sensitivity on the basis of differences in contrast effect. The generated image shows a hyperenhancement pattern in gastrointestinal stromal tumors (sensitivity, 78%-100%; specificity, 60%-100%; accuracy, 60%-100%) and hypoenhancement pattern in benign subepithelial tumors. Contrast-enhanced harmonic endoscopic ultrasound can be used to estimate the malignancy potential of gastrointestinal stromal tumors by evaluating the uniformity of the contrast and the blood vessels inside the tumor, with abnormal intra-tumor blood vessels, heterogeneous enhancement, and non-enhancing spots suggesting malignancy. Contrast-enhanced harmonic endoscopic ultrasound has a higher sensitivity than other imaging modalities for the detection of vascularity within gastrointestinal stromal tumors. Additionally, it has been reported that treatment effects can be estimated by evaluating the blood flow in the gastrointestinal stromal tumor before and after treatment with tyrosine kinase inhibitors using contrastenhanced ultrasound. However, there will be subjective-bias and the results depends on the performer's skill.

LONG-TERM RESULTS OF EXTREMITY SOFT TISSUE SARCOMAS LIMB-SPARING SURGERY AND RADIOTHERAPY

Objective:

To assess the prognostic factors and results of limb sparing surgery and postoperative radiotherapy (PORT) in patients with non-metastatic soft tissue sarcomas (STS) of the extremities.

Methods:

Between 1980-2007, 114 extremity-located STS treated with PORT were analyzed retrospectively. Tumors were mostly localized in the lower extremities (71,9%). The median radiotherapy (RT) dose was 60.9 Gy. Chemotherapy was administered to 37.7% of the patients. Tumor sizes were between 3-26 cm (median 7 cm). The three most frequent histological types included undifferentiated pleomorphic sarcoma (26.3%), liposarcoma (25.4%), and synovial sarcoma (13.2%). The median follow-up for all patients was 60 months, and 81 months for survivors.

Results:

The 5- and 10-year local control (LC) rates were 77% and 70.4%, respectively; actuarial survival rates for 5 and 10 years were 71.8% and 69.1%, respectively. Increasing the dose above 60 Gy for all patients and the patients with positive margins demonstrated a clear benefit on 5-year LC (p=0.03 and p=0.04, respectively). Based on multivariate analysis, the addition of chemotherapy and RT dose were independent prognostic factors for LC. A recurrent presentation significantly affects the disease-free survival.

Conclusions:

PORT for STS of the extremities provides good long-term disease control with acceptable toxicity in a multidisciplinary approach. Level of evidence III, Retrospective study.

Adaptive radiotherapy in patients receiving neoadjuvant radiation for soft tissue sarcoma

AIM

The aim of this study is to evaluate tumor volume changes during preoperative radiotherapy and to assess the role of adaptive radiation.

BACKGROUND

Contemporary neoadjuvant radiotherapy utilizes image guidance for precise treatment delivery. Moreover, it may depict changes in tumor size and shape.

MATERIALS AND METHODS

Between 2016 and 2018, 23 patients aged ≥18 years with soft tissue sarcoma were treated with neoadjuvant radiation followed by surgical resection. The tumor volumes (cc) were measured using the Pinnacle planning system prior to starting radiotherapy and during treatment, the changes in volume and absolute differences were estimated. Moreover, patient's position on the machine was evaluated to assess setup offsets. The triggers for plan adaptation were >1 cm expansion or unacceptable setup offsets.

RESULTS

The mean tumors volume at presentation was 810 cc (range, 55-4000). At last cone beam CT the tumor volume had changed in 14 patients (61%); it was stable in nine patients (39%). Disease regression was documented in eight patients (35%), with median shrinkage of -20.5% (range, -2 to -29%), while tumor progression was observed in six cases (26%), the median change was 12.5% (range, +10 to +25%).Adaptive radiation was required in four patients (17%). For the remaining 19 cases (83%), the dose distribution was adequate to cover target volumes.

CONCLUSIONS

Change in soft tissue sarcoma volume during radiation is not uncommon. Image guidance should be used to reduce setup errors and to detect differences in tumor volume. Image guidance and adaptive radiation are paramount to ensure optimal radiation delivery.

Proteomic Maps of Human Gastrointestinal Stromal Tumor Subgroups

Gastrointestinal stromal tumor (GIST) is a common sarcoma of gastrointestinal tract (GIT) with high metastatic and recurrence rates, but the proteomic features are still less understood. Here we performed systematic quantitative proteome profiling of GIST from 13 patients classified into very low/low, intermediate and high risk subgroups. An extended cohort of GIST (n = 131) was used for immunohistochemical validation of proteins of interest. In total, 9177 proteins were quantified, covering 55.9% of the GIT transcriptome from The Human Protein Altas. Out of the 9177 quantified proteins, 4930 proteins were observed in all 13 cases with 517 upregulated and 187 downregulated proteins in tumorous tissues independent of risk stage. Pathway analysis showed that the downregulated proteins were mostly enriched in metabolic pathway, whereas the upregulated proteins mainly belonged to spliceosome pathway. In addition, 131 proteins showed differentially expressed patterns among GIST subgroups with statistical significance. The 13 GIST cases were classified into 3 subgroups perfectly based on the expression of these proteins. The intensive comparison of molecular phenotypes and possible functions of quantified oncoproteins, tumor suppressors, phosphatases and kinases between GIST subgroups was carried out. Immunohistochemical analysis of the phosphatase PTPN1 (n = 117) revealed that the GIST patients with high PTPN1 expression had low chances of developing metastasis. Collectively, this work provides valuable information for understanding the inherent biology and evolution of GIST.

Evaluation of eight melanocytic and neural crest-associated markers in a well-characterised series of 124 malignant peripheral nerve sheath tumours (MPNST): useful to distinguish MPNST from melanoma?

AIMS

The diagnosis of malignant peripheral nerve sheath tumour (MPNST) may be challenging, especially in the sporadic setting. Owing to the lack of specific histological criteria, immunohistochemical and molecular diagnostic markers, several differential diagnoses must be considered, especially melanoma. Indeed, although S100 protein usually stains melanoma, other melanocytic markers are often negative, especially in spindle cell/desmoplastic types. This pattern of immunoreactivity resembles that of some nerve-derived tumours such as MPNST. Owing to their different clinical behaviours and therapeutic implications, accurate identification of these two different tumours is crucial.

METHODS AND RESULTS

S100, SOX10, KBA62, MITF, HMB45, Melan-A, tyrosinase PNL2 and BRAF-V600E immunostaining was performed in a pathologically and genetically well-characterised cohort of primary MPNST (n = 124), including 66 (53%) NF1-associated tumours. Sox10 and KBA62 expression were found, respectively, in 102 (84%) and in 101 (83%) MPNST, whereas S100 was expressed in 64 cases (52%). We observed an increased loss of S100 with increasing histological grade (P = 0.0052). We found Melan-A expression in 14% (n = 17) of all MPNST, occurring in 82% (n = 14) of cases in an NF1 context. Six per cent (n = 8) of MPNST showed tyrosinase positivity, including seven (87%) NF1-associated. MITF expression was found in 10 (8%) MPNST. None expressed PNL2, HMB45 or BRAF-V600E.

CONCLUSION

MPNST (in NF1 and a sporadic setting) can quite often be positive for Melan-A, tyrosinase and MITF. Pathologists should be cognisant of these exceptions to prevent confusion with melanoma.

Investigating the role of functional imaging in the management of soft-tissue sarcomas of the extremities

Background and purpose

In this work, we validate a texture-based model computed from positron emission tomography (PET) and magnetic resonance imaging (MRI) for the prediction of lung metastases in soft-tissue sarcomas (STS). We explore functional imaging at different treatment time points and evaluate the feasibility of radiotherapy dose painting as a potential treatment strategy for patients with higher metastatic risk.

Materials and methods

We acquired fluorodeoxyglucose (FDG)-PET, fluoromisonidazole (FMISO)-PET, diffusion weighting (DW)-MRI and dynamic contrast enhanced (DCE)-MRI data for 18 patients with extremity STS before, during, and after pre-operative radiotherapy. We tested the lung metastases prediction model using pre-treatment images. We evaluated the feasibility of dose painting using volumetric arc therapy (VMAT) via treatment re-planning with a prescription of 50 Gy to the planning target volume (PTV_50Gy) and boost doses of 60 Gy to the FDG hypermetabolic gross tumour volume (GTV_60Gy) and 65 Gy to the low-perfusion DCE-MRI hypoxic GTV contained within the GTV_60Gy (GTV_65Gy).

Results

The texture-based model for lung metastases prediction reached an area under the curve (AUC), sensitivity, specificity and accuracy of 0.71, 0.75, 0.85 and 0.82, respectively. Dose painting resulted in adequate coverage and homogeneity in the re-planned treatments: D_95% to the PTV_50Gy, GTV_60Gy and GTV_65Gy were 50.0 Gy, 60.3 Gy and 65.4 Gy, respectively.

Conclusions

Textural biomarkers extracted from FDG-PET and MRI could be useful to identify STS patients that might benefit from dose escalation. The feasibility of treatment planning with double boost levels to intratumoural GTV functional sub-volumes was established.

Surgical and oncological long term outcomes of gastrointestinal stromal tumors (GIST) resection- retrospective cohort study

PURPOSE

Surgery remains the mainstay of gastrointestinal stromal tumors (GISTs) treatment. The aim of our study was to compare postoperative outcomes and long term oncologic results of GISTs resection. An analysis of laparoscopic versus open surgery for GISTs and a subgroup analysis of lesions larger than 5 cm were realized.

MATERIALS AND METHODS

Between January 2005 and December 2014, 143 patients with primary GISTs were treated with radical resection in two tertiary centers. Eight patients with metastatic disease were excluded. The remaining patients were assigned to 2 groups: laparoscopy and open surgery. A separate analysis of tumors larger than 5 cm was realized for the laparoscopy group. Long-term follow-up was used to analyze the oncologic and surgical results. Relevant clinical variables were evaluated using univariate and multivariate analyses.

RESULTS

With similar oncological outcomes(p = 0.09) and morbidity(p = 0.56), laparoscopy compared to open surgery significantly reduced length of hospitalization (p = 0.01). For lesions >5 cm laparoscopic resection is associated with similar short-term outcomes with resection for small tumors without compromising oncological outcomes (p = 0.89). For all patients, the probability of remaining disease free at 3 years, and 5 years was 97, 6% and 95%, respectively.

CONCLUSION

Laparoscopic resection is a technically and oncologically safe and feasible approach for GISTs compared with open resection. Resection of lesions superior of 5 cm by laparoscopy has efficacy and recurrence rates similar to open surgical controls. Large tumor resection should only be attempted by surgeons with a large experience with minimally invasive surgery in order to avoid operative complications and unfavorable long term outcome.

Synovial Sarcoma Is Not Associated With a Higher Risk of Lymph Node Metastasis Compared With Other Soft Tissue Sarcomas

BACKGROUND

Reported rates of the incidence of lymph node metastasis in soft tissue sarcoma vary considerably. Many are based on single-institution series and small patient populations. Certain sarcoma subtypes, including synovial sarcoma, have been associated with a higher risk of lymph node involvement. Most single centers have insufficient numbers of patients to assess lymph node metastasis accurately, but larger national databases may allow a more accurate estimation.

QUESTIONS/PURPOSES

We queried a large national database and asked the following questions: (1) What proportion of patients with soft tissue sarcoma have lymph node metastasis and distant metastasis? (2) What histologic subtypes are associated with increased risk of nodal metastasis? (3) What is the impact of lymph node metastases and histologic subtype on survival? (4) Does lymph node excision improve survival of patients with soft tissue sarcoma?

METHODS

The National Cancer Institute's Surveillance, Epidemiology, and End Results (SEER) Program is a national database that covers a geographic cross-section representing approximately 28% of the US population across demographic groups. Using the SEER database, we identified 15,525 adults diagnosed with histologically confirmed soft tissue sarcoma from 2004 to 2013. Proportions of patients with lymph node or distant metastases were calculated using descriptive statistics. Overall survival was computed using the Kaplan-Meier method. Multivariate analysis was performed using Cox proportional hazard regression to calculate the association of lymph node metastasis with overall survival while controlling for patient age, sex, race, tumor size, and tumor location.

RESULTS

A total of 820 of 15,525 patients had lymph node metastasis at the time of diagnosis, yielding an overall proportion of 5.3% (95% confidence interval [CI], 4.9%-5.6%). Histologic subtypes that most frequently developed nodal metastasis were rhabdomyosarcoma, clear cell sarcoma, epithelioid sarcoma, and myxoid/round cell liposarcoma. Despite frequent reports regarding its association with lymph node metastasis, the proportion of patients with lymph node metastasis among 885 patients with synovial sarcoma (4.2%) was not different from the proportion with nodal metastasis in the overall soft tissue sarcoma population. For all soft tissue sarcomas, distant metastatic disease was present at diagnosis in 1869 (12%) patients (95% CI, 11.5%-12.6%). After controlling for relevant covariates, lymph node metastasis was associated with poorer overall survival (hazard ratio [HR], 1.34; 95% CI, 1.22-1.48; p < 0.001) as was distant metastasis (HR, 2.87; 95% CI, 2.66-3.09; p < 0.001). When comparing the subgroup of patients with positive lymph nodes, lymphadenectomy in conjunction with local excision/limb salvage was associated with the highest overall 5-year survival (HR, 0.46; 95% CI, 0.31-0.67; p < 0.001).

CONCLUSIONS

In clarifying the overall proportion of patients with soft tissue sarcoma with nodal metastases, the current study indicates that lymph node metastases occur at a higher proportion than previous studies have suggested and that synovial sarcoma is not associated with a higher risk of lymphatic spread compared with soft tissue sarcoma overall. Patients with lymph node metastases are associated with poorer survival than those without metastases. Further investigation is needed to clarify the apparent improved overall survival after lymphadenectomy in the setting of nodal metastasis from soft tissue sarcoma.

LEVEL OF EVIDENCE

Level II, prognostic study.

Loss of H3K27 trimethylation is not suitable for distinguishing malignant peripheral nerve sheath tumor from melanoma: a study of 387 cases including mimicking lesions

The diagnosis of malignant peripheral nerve sheath tumor remains challenging, especially in the sporadic setting. Malignant peripheral nerve sheath tumor is a rare malignancy, and owing to the lack of specific histological criteria, immunohistochemical and molecular diagnostic markers, several differential diagnoses must be considered, in particular melanoma. Recently, inactivation of the polycomb repressive complex 2 (PRC2), induced by inactivating mutations in two of its critical constituents SUZ12 and EED, was reported in a large subset of malignant peripheral nerve sheath tumors. Homozygous PRC2 inactivation induces complete loss of trimethylation at lysine 27 of histone 3 (H3K27me3). Recent studies suggest that complete loss of H3K27me3 is highly specific for malignant peripheral nerve sheath tumor and may be a useful immunohistochemical diagnostic marker. Therefore, to determine the specificity of the complete loss of H3K27me3 expression in the context of the differential diagnosis of malignant peripheral nerve sheath tumor from melanoma (its major potential mimic), we performed H3K27me3 immunohistochemistry in a pathologically and genetically well-characterized cohort of primary (neurofibromatosis type 1 (NF1), radiation-associated and sporadic context) malignant peripheral nerve sheath tumors (n=122) and in a cohort or primary (desmoplastic) and metastatic melanomas (n=265). In total, 88 (72%) malignant peripheral nerve sheath tumors, including 46 (71%) NF1-associated, 4 (100%) radiation-associated, and 38 (72%) sporadic tumors, showed complete loss of H3K27me3. We observed increased loss of H3K27me3 with increasing histological grade. Interestingly, we found complete loss of H3K27me3 in 37% (n=98) of all melanomas, including 25% (n=9) of primary desmoplastic melanomas. Moreover, partial loss ('mosaic' pattern) was observed in 23 (19%) of all malignant peripheral nerve sheath tumors and in 136 (51%) of all melanomas. Complete loss of H3K27me3 detected by immunohistochemistry is not specific for malignant peripheral nerve sheath tumor and cannot be used safely when distinguishing malignant peripheral nerve sheath tumor from melanoma.

Prognostic factors and outcome of Liposarcoma patients: a retrospective evaluation over 15 years

BACKGROUND

Soft tissue sarcomas are rare entities with over 50 histological subtypes. Liposarcoma (LS) is the most common neoplasm in this group; it is a complex neoplasm that is divided into different histological subtypes. Different therapy options, such as surgical resection, radiation, and chemotherapy, are available. Depending on the subtype, location, status of the resection margins and metastatic status, different therapy options are used. Therefore, the aim of this study was to determine the prognostic factors influencing the survival of patients affected by LS with consideration for the grading, histological subtype, state of the resection margin, size, location, metastases and local recurrence in a retrospective, single-centre analysis over 15 years.

METHODS

We included 133 patients (male/female = 67/66) in this study. We recorded the histologic subtype, grade, TNM classification, localization, biopsy technique, tumour margins, number of operations, complications, radiation and dose, chemotherapy, survival, recrudescence, metastases and follow-up. Survivorship analysis was performed.

RESULTS

We detected 56 (43%; 95%-CI 34.6-51.6%) atypical LS cases, 21 (16.2%; 95%-CI 9.8-22.5) dedifferentiated LS cases, 40 (30.8%; 95%-CI 22.8-38.7) myxoid LS cases and 12 (9.2%; 95%-CI 4.3-14.2) pleomorphic LS cases. G1 was the most common grade, which was followed by G3. Negative margins (R0) were detected in 67 cases (53.6%; 95%-CI 44.9-62.3) after surgical resection. Local recurrence was detected in 23.6% of cases. The presence of metastases and dedifferentiated LS subtype as well as negative margins, grade and tumour size are significant prognostic factors of the survival rates (p < 0.015).

CONCLUSION

Grading, LS subtype, negative margins after surgery, metastases and tumour size are independently associated with disease-specific survival, and patients with local recurrence had lower survival rates. We hope our investigation may facilitate a further prospective study and clinical decision-making in LS.

Long-term outcomes of endoscopic resection of gastric GISTs

OBJECTIVE

Although the endoscopic treatment of gastric stromal tumors is a recently accepted therapy, the long-term outcomes of this approach remain unknown. The aims of this study were to assess the long-term effectiveness and safety of endoscopic resection for gastric GISTs.

METHODS

A total of 60 consecutive patients undergoing endoscopic resection of gastric GISTs were enrolled in a retrospective single-center study. Clinical data, perioperative complications, histopathologic characteristics of the tumors, and long-term outcomes were recorded.

RESULTS

Sixty patients successfully underwent complete resection of lesions, including 25 cases of endoscopic submucosal dissection (ESD) and 35 cases of endoscopic full-thickness resection (EFTR), with an average tumor size of 1.76 ± 1.55 cm (range 0.5-7.6 cm). The average operation time was 43.97 ± 26.95 min (range 11.7-138.9 min). Two cases were observed with an intraoperative hemorrhage of 200 mL, which were successfully managed by hemostatic forceps. Perforations of 2-11 mm of ESD occurred in four cases (4/25) and were well closed with endoclips, with no conversions to surgical operation. Mucosal laceration of esophagus occurred in 1 case, when a large tumor was removed. The average length of hospitalization was 6.50 ± 3.06 days (range 3-21 days). Out of a total of 60 patients, 44 (73.3%) were at very low risk, 10 (16.7%) were at low risk, 5 (8.3%) were at intermediate risk, and 1 (1.7%) was at high risk. All patients were followed-up for 36.15 ± 12.92 months (range 14-73 months). Primary tumor recurrence occurred in 1 patient who underwent a second operation after 32 months, and no other cases were observed to have either tumor recurrence or metastasis.

CONCLUSIONS

For long-term outcomes, endoscopic resection of ESD or EFTR is a safe and effective approach for removing gastric stromal tumors (<5 cm), and it can be a resection technique for them with no metastasis.

Pancreatic Metastasis from Gastrointestinal Stromal Tumor of the Stomach: A Case Report

We report the first documented case of pancreatic metastasis from a gastrointestinal stromal tumor of the stomach. A 42-year-old Japanese man presented with severe abdominal discomfort. Computed tomography of the abdomen showed a huge heterogeneous mass consisting of cystic and solid components in the left upper abdomen. (18)F-Fluorodeoxyglucose positron-emission tomography revealed high tracer uptake in the abdominal mass. After total gastrectomy with lymphnodectomy was performed, a hard mass was palpated in the pancreatic tail. The pancreatic tumor was also resected under the therapeutic strategy. Histological examinations of the resected gastric and pancreatic specimens revealed that both tumors consisted of uniform spindle cells with a fascicular growth pattern and were immunohistochemically positive for CD34 and CD117/KIT. Gene sequencing analysis of DNA from each tumor revealed an identical deletion of 21 nucleotides in exon 11 of the gene KIT. On the basis of these results, we concluded that the pancreatic tumor was a metastatic tumor from the gastrointestinal stromal tumor of the stomach.

Effect of intraoperative radiotherapy in the treatment of retroperitoneal sarcoma

BACKGROUND

Current National Comprehensive Cancer Network guidelines for the treatment of retroperitoneal sarcomas (RPS) endorse surgical resection, but the role of radiotherapy (RT) is less clear. We investigate the utilization and benefits of intraoperative RT (IORT) in the treatment of RPS.

METHODS

We queried the Surveillance, Epidemiology and End Results (SEER) database (1988-2013) for the utilization of IORT and perioperative external beam RT (EBRT) in patients who underwent surgical resection of RPS. Groups were defined as any IORT (aIORT), IORT alone (IORT-), IORT with EBRT (IORT+) and preoperative and/or postoperative EBRT without IORT (EBRT). Demographics, tumor characteristics, extent of disease, and survival were compared between groups.

RESULTS

We identified 908 patients with RPS who underwent surgical resection with perioperative RT. Demographics of age, sex, and race were similar between groups. There was no difference in baseline tumor characteristics of mean size, tumor grade, or histological subtype between groups. A higher percentage of patients receiving aIORT had tumors >20 cm in size, and extension beyond local tissues. Liposarcoma and leiomyosarcoma were the most common subtypes overall and in each subgroup. Patients with liposarcoma undergoing IORT and EBRT (IORT+) demonstrated a survival benefit over both IORT alone (IORT-) and EBRT alone.

CONCLUSION

IORT was used infrequently for RPS but generated equivalent outcomes compared to EBRT, despite being utilized more often for larger tumors and those with peri-tumoral soft-tissue invasion. Patients with the most common subtype (liposarcoma) may benefit from combination IORT with adjuvant EBRT versus other regimens.

Salivary gland adenoid cystic carcinoma

Malignant fibrous histiocytoma, also known as pleomorphic undifferentiated sarcoma not otherwise specified, arises in numerous organs. The first-line treatment is complete excision of the mass, but in some cases postoperative chemo- and/or radiotherapy is recommended. Only a few cases of malignant fibrous histiocytoma of the vocal fold have been previously reported in the literature. We report a new case, which originated in the true vocal fold of a 65-year-old man. The mass was removed via CO2 laser excision with preservation of the vocal fold and without the need for further treatment. At 3 years of follow-up, the patient remained recurrence-free.

CT-guided 125I seed implantation for inoperable retroperitoneal sarcoma: A technique for delivery of local tumor brachytherapy

Radical surgery is currently the first treatment of choice for retroperitoneal soft tissue sarcoma (RSTS). However, the prognosis of RSTS remains poor due to ineffective local control and a high incidence of metastasis after surgical resection. Brachytherapy has been shown to safely provide local radiotherapy for numerous types of cancer when used alone or in combination with surgical resection, but has not been well characterized in the management of RSTS. The aim of this study was to evaluate CT-guided 125I seed implantation for local control and pain relief in the treatment of inoperable RSTS. A total of 23 patients with RSTS were treated with 125I implantation. Pain was assessed using a visual analog scale. Other endpoints were evaluated via computed tomography scan or phone call/e-mail records. The occurrence of complications was assessed preoperatively (baseline) and during postoperatively follow-up or until patient succumbed. All patients were successfully treated with 125I implantation. A mean number of 70.87 radioactive seeds were applied in each patient. During the follow-up, two patients were unaccounted for, local recurrence occurred in three patients, five succumbed and complications were observed in sixteen. The patient's VAS score changed from 7.4 preoperatively to 7.6, 2.3, 2.0, 1.2, 1.5, 1.4 and 2.5 at 24 h, 1, 3, 6, 12, 24 and 36 months after the procedure, respectively. Good local control and significant pain relief after 125I seed implantation was observed in patients with inoperable RSTS. Thus, the present results suggest that this method could be an effective treatment option for patients with inoperable RSTS.

Proximal Interphalangeal Joint Fibromatosis After Pyrocarbon Implant Insertion: A Case Report

Background: Pyrocarbon implants represent an increasingly popular method to treat proximal interphalangeal joint dysfunction. To this point, no association has been shown between pyrocarbon biomaterials and fibromatosis. We present a potentially serious and destructive complication associated with pyrocarbon arthroplasty. Methods: We demonstrate a clinical case involving pyrocarbon arthroplasty and subsequent fibromatosis development in an otherwise healthy 23-year-old female. To present this association, we illustrate the diagnostic workup involved in a rapidly expanding soft tissue mass of the hand and explain the appropriate treatment. Results: Pyrocarbon arthroplasty was associated with development of locally destructive fibromatosis confirmed by histopathological examination. Treatment involved wide resection with preservation of local structures. Conclusion: We describe the first association between fibromatosis and pyrocarbon biomaterial. Due to fibromatosis destructive effects, clinicians should be aware of potential complications associated with these materials and know how to accurately diagnose and treat these lesions.

Superficial CD34-positive fibroblastic tumor: Cytologic features, tissue correlation, ancillary studies, and differential diagnosis of a recently described soft tissue neoplasm

Superficial CD34-positive fibroblastic tumor is a low-grade mesenchymal neoplasm of superficial soft tissues characterized by fascicles of spindle to epithelioid cells displaying nuclear pleomorphism and strong diffuse CD34 immunoreactivity. The intraoperative imprint cytology preparations (ICP) of a superficial CD34-positive fibroblastic tumor from a 50-year-old female are described. To the best of our knowledge, there is no report of the cytologic findings of superficial CD34-positive fibroblastic tumor in the English medical literature. The ICP, differential diagnosis, tissue correlation, and ancillary studies of this fascinating entity are discussed. Diagn. Cytopathol. 2016;44:926-930. © 2016 Wiley Periodicals, Inc.

Long-term progress of six cases of malignant peripheral nerve sheath tumors of the mediastinum that underwent surgical treatment: Case report series

INTRODUCTION

Malignant Peripheral Nerve Sheath Tumor is a rare type of soft tissue malignant tumor that occurs in only 5% of cases. It tends to occur in the arms and legs and trunk of the body, with mediastinal occurrence in only a few cases. Among mediastinal tumors, only 18.8% occur primarily in the nerves, and of these, only 10.3% are malignant, with very few reports indicating the long-term progress of patients with MPNST of the mediastinum.

CASE PRESENTATION

We studied six cases of mediastinal primary malignant peripheral nerve sheath tumors in which surgery was carried out at this Center between 1977 and 2000. Four of the cases were men and two were women. The period of observation was between 14 and 277 months and the median follow-up time was 119.5 months. The tumors were contained in a membrane and completely excisable in three cases, with the patient demonstrating long-term survival with no recurrence in each case. The remaining three cases were not completely excisable due to invasion into the aorta. In two cases, the patients were treated post-surgically with chemotherapy; however, in all three cases the patient died as a result of the original condition.

DISCUSSION AND CONCLUSIONS

Nerve sheath tumors localized within the membrane offer good long-term prognosis even if malignant. Furthermore, long-term survival is possible even if the tumor has invaded neighboring organs, provided it can be completely excised. In cases where complete excision is difficult, a multidisciplinary approach including radiotherapy and anti-cancer drug treatment may contribute to improved prognosis but this is a subject that requires further study.

The Challenge of Cancer Genomics in Rare Nervous System Neoplasms: Malignant Peripheral Nerve Sheath Tumors as a Paradigm for Cross-Species Comparative Oncogenomics

Comprehensive genomic analyses of common nervous system cancers provide new insights into their pathogenesis, diagnosis, and treatment. Although analogous studies of rare nervous system tumors are needed, there are major barriers to performing such studies. Cross-species comparative oncogenomics, identifying driver mutations in mouse cancer models and validating them in human tumors, is a promising alternative. Although still in its infancy, this approach is being applied to malignant peripheral nerve sheath tumors (MPNSTs), rare Schwann cell-derived malignancies that occur sporadically, after radiotherapy, and in neurofibromatosis type 1. Studies of human neurofibromatosis type 1-associated tumors suggest that NF1 tumor suppressor loss in Schwann cells triggers cell-autonomous and intercellular changes, resulting in development of benign neurofibromas; subsequent neurofibroma-MPNST progression is caused by aberrant growth factor signaling and mutations affecting the p16(INK4A)-cyclin D1-CDK4-Rb and p19(ARF)-Mdm2-p53 cell cycle pathways. Mice with Nf1, Trp53, and/or Cdkn2a mutations that overexpress the Schwann cell mitogen neuregulin-1 or overexpress the epidermal growth factor receptor validate observations in human tumors and, to various degrees, model human tumorigenesis. Genomic analyses of MPNSTs arising in neuregulin-1 and epidermal growth factor receptor-overexpressing mice and forward genetic screens with Sleeping Beauty transposons implicate additional signaling cascades in MPNST pathogenesis. These studies confirm the utility of mouse models for MPNST driver gene discovery and provide new insights into the complexity of MPNST pathogenesis.

Aggressive Surgical Resection Combined With Imatinib Therapy for Liver Metastases From a Gastrointestinal Stromal Tumor

The use of imatinib mesylate has influenced survival in patients with advanced gastrointestinal stromal tumors (GISTs). However, whether a combination of imatinib and surgical resection can further prolong survival in these patients has not yet been fully elucidated. We report a case of a 59-year-old woman with multiple liver metastases from a jejunal GIST. The patient received imatinib therapy after partial resection of the jejunum, and she subsequently underwent right hepatic trisectionectomy. However, liver metastasis was detected again after surgery. Secondary imatinib therapy was started, and the patient underwent partial hepatectomy at the left lateral segment. Postoperatively, the patient underwent imatinib treatment and has survived without recurrence for 3 years. Imatinib is recommended for the treatment of advanced GIST; however, a complete response is rare, and approximately half of all patients develop resistance to imatinib. Aggressive surgical resection combined with imatinib may be effective for the control of advanced GIST.

A radiomics model from joint FDG-PET and MRI texture features for the prediction of lung metastases in soft-tissue sarcomas of the extremities

This study aims at developing a joint FDG-PET and MRI texture-based model for the early evaluation of lung metastasis risk in soft-tissue sarcomas (STSs). We investigate if the creation of new composite textures from the combination of FDG-PET and MR imaging information could better identify aggressive tumours. Towards this goal, a cohort of 51 patients with histologically proven STSs of the extremities was retrospectively evaluated. All patients had pre-treatment FDG-PET and MRI scans comprised of T1-weighted and T2-weighted fat-suppression sequences (T2FS). Nine non-texture features (SUV metrics and shape features) and forty-one texture features were extracted from the tumour region of separate (FDG-PET, T1 and T2FS) and fused (FDG-PET/T1 and FDG-PET/T2FS) scans. Volume fusion of the FDG-PET and MRI scans was implemented using the wavelet transform. The influence of six different extraction parameters on the predictive value of textures was investigated. The incorporation of features into multivariable models was performed using logistic regression. The multivariable modeling strategy involved imbalance-adjusted bootstrap resampling in the following four steps leading to final prediction model construction: (1) feature set reduction; (2) feature selection; (3) prediction performance estimation; and (4) computation of model coefficients. Univariate analysis showed that the isotropic voxel size at which texture features were extracted had the most impact on predictive value. In multivariable analysis, texture features extracted from fused scans significantly outperformed those from separate scans in terms of lung metastases prediction estimates. The best performance was obtained using a combination of four texture features extracted from FDG-PET/T1 and FDG-PET/T2FS scans. This model reached an area under the receiver-operating characteristic curve of 0.984 ± 0.002, a sensitivity of 0.955 ± 0.006, and a specificity of 0.926 ± 0.004 in bootstrapping evaluations. Ultimately, lung metastasis risk assessment at diagnosis of STSs could improve patient outcomes by allowing better treatment adaptation.

Rhabdomyoblastic Differentiation in Head and Neck Malignancies Other Than Rhabdomyosarcoma

Rhabdomyosarcoma is a relatively common soft tissue sarcoma that frequently affects children and adolescents and may involve the head and neck. Rhabdomyosarcoma is defined by skeletal muscle differentiation which can be suggested by routine histology and confirmed by immunohistochemistry for the skeletal muscle-specific markers myogenin or myoD1. At the same time, it must be remembered that when it comes to head and neck malignancies, skeletal muscle differentiation is not limited to rhabdomyosarcoma. A lack of awareness of this phenomenon could lead to misdiagnosis and, subsequently, inappropriate therapeutic interventions. This review focuses on malignant neoplasms of the head and neck other than rhabdomyosarcoma that may exhibit rhabdomyoblastic differentiation, with an emphasis on strategies to resolve the diagnostic dilemmas these tumors may present. Axiomatically, no primary central nervous system tumors will be discussed.

Comorbidity is independently associated with poor outcome in extremity soft tissue sarcoma

Background

Comorbidity has not been examined as an independent prognostic factor in soft tissue sarcoma (STS). We examined the prognostic impact of comorbidity on oncologic outcome in STS with an adjustment for possible confounding factors.

Methods

A retrospective review was performed on 349 patients who had undergone surgery for high-grade localized STS of extremity at our institute. Conditions known to alter the risk of mortality, as defined in the Charlson comorbidity index, were classified as comorbidities and 43 patients (12%) had at least one comorbidity at the time of surgery. The association of comorbidity and oncologic outcomes of local recurrence-free survival (LRFS) and disease-specific survival (DSS) were tested with adjustment for confounding factors.

Results

Comorbidity was associated with old age, high tumor grade, and large tumor size. The presence of comorbidity was independently associated with poor LRFS and DSS, even after adjusting for confounding factors including age and treatment variables.

Conclusions

Our data suggest that the presence of comorbidity is an independent prognostic factor for extremity STS.

Usefulness of laparoscopic side-to-side duodenojejunostomy for gastrointestinal stromal tumors located at the duodenojejunal junction

BACKGROUND

Surgery for gastrointestinal stromal tumor (GIST) at the duodenojejunal junction is a technically challenging and difficult procedure because of the anatomical complexity. When it comes to laparoscopic surgery, it is more challenging than open surgery. This study aimed to introduce our laparoscopic procedure and to evaluate its clinical implication by comparing with open procedures.

METHOD

Between 2003 and 2013, 19 patients underwent segmental resection for a GIST at the duodenojejunal junction: laparoscopic segmental resection with side-to-side duodenojejunostomy (n = 8) and open surgery (n = 11). Clinicopathological findings, operation details, and postoperative outcomes were compared.

RESULTS

Both groups were comparable in demographics and clinicopathological characteristics. Postoperative hospital stay of the laparoscopic group (6.3 days) was significantly shorter than the open group (15.7 days, P = 0.008) while no significant differences were observed regarding estimated blood loss, operation time, and morbidity. All patients in both groups underwent curative resection without operative mortality. Two patients experienced recurrence after open surgery whereas none of the patients after laparoscopic duodenojejunostomy had recurrence with a median follow-up period of 36 months.

CONCLUSION

Laparoscopic segmental resection with side-to-side duodenojejunostomy for a GIST at the duodenojejunal junction is a safe, feasible, and effective alternative to open approach, providing benefits of minimally invasive surgery.

Hemangiopericytoma of the spleen

INTRODUCTION

Hemangiopericytoma of the spleen is a very rare tumor, with 14 isolated reports. It was our aim to review our experience and compare it with all the reported cases in an attempt to standardize surgical treatment, adjuvant treatment and follow-up protocol of this infrequent condition.

METHODS

A consecutive case series study, with a mean follow-up of 44 months. Five patients (mean age, 49 years) underwent simple splenectomy for hemangiopericytoma limited to the spleen followed by adriamycin-based chemotherapy in one patient.

RESULTS

All the patients are alive and free from disease.

CONCLUSIONS

For tumors confined to the spleen, simple splenectomy can be considered curative, without any need for further adjuvant treatment. On review of the medical literature, cure can still be achieved with complete resection of recurrences, when feasible, with adjuvant chemotherapy being also indicated. The slow-growing pattern of the tumor suggests a 10-year follow-up.

Incidence and Treatment Pattern of Extremity Soft Tissue Sarcoma in Korea, 2009-2011: A Nationwide Study Based on the Health Insurance Review and Assessment Service Database

Purpose

We conducted a nationwide study to assess the incidence and treatment patterns of extremity soft tissue sarcoma (STS) in South Korea.

Materials and Methods

The nationwide incidence and treatment patterns of extremity STS were assessed using two nationwide databases, the Korea National Cancer Incidence (KNCI) database and the Health Insurance Review and Assessment Service (HIRA) database.

Results

A total of 1,236 patients were newly diagnosed with extremity STS during the 3-year study period, from 2009 to 2011. The annual incidence of extremity STS in the Korean population was approximately 0.9 per 100,000 people with a male bias that increased with age and was especially pronounced amongst individuals aged > 80 years. Approximately 7% of patients did not receive any treatment, and surgical excision was performed for 85% of those who were treated.

Conclusion

This is the first nationwide study of the incidence and treatment patterns of extremity STS in Korea using two national databases (KNCI and HIRA), which include the entire Korean population. The results of this study may be useful for future planning and management of STS, at the national level.

[Nerve sheath tumours]

Peripheral nerve sheath tumors are common neoplasms in daily practice. Diagnosis and classification of most conventional peripheral nerve sheath tumors are relatively straightforward for the experienced observer; but on occasion, they are diagnostically challenging (especially with locally aggressive and malignant tumors). This article aims to provide an update of the data (clinical, histological, immunohistochemistry and genomic) of benign, intermediate and malignant peripheral nerve sheath tumors, thanks to the latest WHO "Classification of Tumors of Soft Tissue and Bone", published in 2013, which includes a new chapter on "Nerve Sheath Tumors". Advances in molecular biology have provided new insights into the nature of the various peripheral nerve sheath tumors, and have begun to suggest novel targeted therapeutic approaches.

Fractioned dose regimen of sunitinib for patients with gastrointestinal stromal tumor: a pharmacokinetic and treatment efficacy study

AIM: Sunitinib has shown benefit in patients with imatinib (IM)–resistant gastrointestinal stromal tumor (GIST). However, its advantages are somewhat diminished because of associated toxicities. Herein, we clarify the efficacy and safety of fractioned dose regimen of sunitinib by a pharmacokinetic and efficacy study. MATERIALS AND METHODS: Between 2001 and March 2013, a total of 214 patients with metastatic GIST was treated at Chang Gung Memorial Hospital. Among them, 55 (11.6%) patients who received sunitinib were investigated. One group of patients was administered with standard dose of once-daily sunitinib (standard dose group) and the other group was administered with standard total daily dose of sunitinib in fractioned doses (fractioned dose group). RESULTS: Thirty-two male and 23 female patients with a median age of 55 years received sunitinib. The median duration of sunitinib administration was 9.2 months. The clinical benefit was 65.2%. The mean peak blood level of sunitinib in patients with fractioned doses was significantly lower than that in those with once-daily dose (83.4 vs 50.1 ng/ml, P = .01). The rates of adverse effects of hand-foot syndrome, mucositis, and yellow skin were significantly decreased by fractioned doses of sunitinib. However, the progression-free and overall survival did not differ between patients with different treatment regimens. CONCLUSION: The fractioned dose regimen of sunitinib appears to be a safe and effective treatment for patients with IM-resistant/intolerant GISTs. Significantly decreased toxicity of this regimen could be explained by significantly lower peak sunitinib blood level. However, the treatment efficacy is not reduced by this regimen.

Post-metastasis survival in extremity soft tissue sarcoma: a recursive partitioning analysis of prognostic factors

BACKGROUND

Recursive partitioning analysis (RPA) enables grouping of patients into homogeneous prognostic groups in a visually intuitive form and has the capacity to account for complex interactions among prognostic variables. In this study, we employed RPA to generate a prognostic model for extremity soft tissue sarcoma (STS) patients with metastatic disease.

METHODS

A retrospective review was conducted on 135 patients with metastatic STS who had undergone surgical removal of their primary tumours. Patient and tumour variables along with the performance of metastasectomy were analysed for possible prognostic effect on post-metastatic survival. Significant prognostic factors on multivariate analysis were incorporated into RPA to build regression trees for the prediction of post-metastatic survival.

RESULTS

RPA identified six terminal nodes based on histological grade, performance of metastasectomy and disease-free interval (DFI). Based on the median survival time of the terminal nodes, four prognostic groups with significantly different post-metastatic survival were generated: (1) group A: low grade/metastasectomy; (2) group B: low grade/no metastasectomy/DFI ⩾ 12 months or high grade/metastasectomy; (3) group C: low grade/no metastasectomy/DFI < 12 months or high grade/no metastasectomy/DFI ⩾ 12 months; and (4) group D: high grade/no metastasectomy/DFI < 12 months. The 3-year survival rates for each group were: group A, 76.1 ± 9.6%; group B, 42.3 ± 10.3%; group C, 18.8 ± 8.0%; and group D, 0.0 ± 0.0%.

CONCLUSION

Our prognostic model using RPA successfully divides STS patients with metastasis into groups that can be easily implemented using standard clinical parameters.

Acral myxoinflammatory fibroblastic sarcoma: A case report and literature review

Acral myxoinflammatory fibroplastic sarcoma is an extremely rare soft-tissue sarcoma. It typically presents as an inflammatory mass in the distal extremities of adult patients. The authors present a review of the available literature as well as a discussion on the surgical management of a patient with acral myxoinflammatory fibroplastic sarcoma who originally requested conservative management but ultimately required a two-digit ray amputation after local recurrence.

A rare case of peritoneal disseminated angiosarcoma 20 years after ovarian cancer diagnosis

Angiosarcoma is a rare form of sarcoma which may be either a primary tumor or it may result from previous irradiation because of another tumor. In this paper, we present a case of a female patient diagnosed as having peritoneal disseminated angiosarcoma 20 years after ovarian cancer treatment (surgery, chemotherapy and radiotherapy). The case was very atypical because of an extremely rare peritoneal location and disseminated nature of the changes. Based on the initial histological picture, poorly differentiated cancer metastasis was diagnosed, suggesting a recurrence of the ovarian cancer that had been diagnosed earlier. The time elapsed from the ovarian cancer diagnosis, history of the previous irradiation and concentration of tumor markers were the only additional clinical data provided to the pathologists, which ultimately contributed to a correct diagnosis. The case we present herein shows and emphasizes the importance of proper communication between a clinician and a pathologist, which is a prerequisite for a correct diagnosis and, consequently, for proper treatment of patients. It also confirms the high specificity of the HE4 (human epididymis protein 4) marker in the monitoring of ovarian cancer, which was within normal limits in spite of peritoneal tumor dissemination.

Limb function after excision of a deltoid muscle sarcoma

BACKGROUND

Limb function after excision of deltoid muscle sarcomas has not been thoroughly investigated, although a large defect of soft tissue often causes some degree of dysfunction after wide excision. We formulated a hypothesis that the limb functional results depend on the volume of the excised deltoid muscle and examined the clinical outcomes in patients with a sarcoma in the deltoid muscle treated by surgical resection.

METHODS

The clinical outcomes of 8 patients with a malignant soft tissue tumor in the deltoid muscle were retrospectively reviewed. The following items were evaluated: type of excision of the deltoid muscle, including total excision, subtotal excision, and partial excision; surgical margins; reconstruction procedure used; postoperative complications; local recurrence; metastasis; survival; and functional results (determined by the Musculoskeletal Tumor Society scoring system).

RESULTS

After surgical resection, reconstruction in 6 of 8 patients was performed by pedicled latissimus dorsi musculocutaneous or muscle flap or pedicled trapezius musculocutaneous flap. Two patients did not undergo reconstruction because skin closure was possible. The partial excision group had a Musculoskeletal Tumor Society score of 100.0%, and the subtotal excision case and the total excision group had scores of 76.6% and 82.2%, respectively. None of the patients has demonstrated any evidence of local recurrence.

CONCLUSION

We conclude that the functional results may depend on the volume of the excised deltoid muscle. Latissimus dorsi and trapezius musculocutaneous flaps were found to be useful for covering a defect of the deltoid muscle, although these flaps did not contribute to function of the shoulder.