The diagnosis and management of desmoplastic small round cell tumor: a review. Curr Opin Oncol. 2011;23:385-389. [PMID: 21577112 DOI: 10.1097/cco.0b013e3283477aab]

"Putting the cart before the horse": an update on promiscuous gene fusions in soft tissue tumors

The ever-increasing availability and affordability of molecular genetic testing has revolutionized our understanding of the pathogenesis and proper classification of soft tissue tumors but has also brought new challenges. As is known, many soft tissue tumors harbor gene fusion events, and while it was initially thought that individual entities would be defined by single, specific fusions, it quickly became clear that some entities could be caused by several different fusion events (e.g., EWSR1::FLI1, EWSR1::ERG, EWSR1:FEV and others in Ewing sarcoma). More recently, it has become apparent that these fusion events themselves are "promiscuous", appearing in more than one discrete entity (e.g., EWSR1::CREB1 in clear cell sarcoma, angiomatoid fibrous histiocytoma and others). This review article will briefly discuss the best known examples of genetic promiscuity, the EWSR1/FUS::ATF1/CREB1 and ETV6::NTRK3 fusions, and more comprehensively cover recently discovered and less well-known examples of genetic promiscuity, including EWSR1::WT1, MALAT1::GLI1, YAP1::TFE3 and fusions involving members of the FET and ETS gene families.

A case report of chest wall desmoplastic small round cell tumor in children

INTRODUCTION

Desmoplastic small round cell tumor (DSRCT) is a rare sarcoma predominantly afflicting young males.

CASE PRESENTATION

In this current report, a two-year-old boy was admitted to the hospital for the evaluation of a left chest wall mass. Imaging revealed the tumor's presence in the left chest, compressing lung tissue. Subsequently, histological analysis confirmed the DSRCT diagnosis following a biopsy. The patient underwent a comprehensive management strategy centered around surgery, successfully completing the entire treatment course without experiencing relapse during subsequent follow-up assessments.

DISCUSSION

When chest wall tumors are inoperable upon initial diagnosis, a biopsy is essential to clarify the pathology and assist in the diagnostic process. If a patient is diagnosed with DRSCT and conventional chemotherapy fails with surgical resection still not feasible, timely adjustment of the chemotherapy regimen coupled with targeted drug administration can reduce the tumor, enable complete resection, and improve the overall prognosis.

CONCLUSION

DSRCT is a rare malignancy associated with a generally poor prognosis. The administration of a combined treatment approach involving oral targeted medication (anlotinib), chemotherapy, radiotherapy, and aggressive surgical resection holds the potential to enhance the prognosis for pediatric patients with this condition.

Desmoplastic small round cell tumor of the abdomen: A case report

RATIONALE

Desmoplastic small round cell tumor (DSRCT) is a rare malignant tumor with poor prognosis, usually involving the peritoneum. There are currently no standardized treatment approaches. This study helped to further advance our understanding of DSRCT, and help to guide therapy.

PATIENT CONCERNS

The patient, a 19-year-old male, presented with left-sided back pain with no obvious cause and occasional abdominal pain, and underwent abdominal electron computed tomography examination in our hospital suggesting consideration of small bowel mesenchymal tumor with possible multiple implantation metastasis in the abdominopelvic cavity.

DIAGNOSES

After surgical treatment, the pathology report suggested a DSRCT, and immunohistochemistry and fluorescence in situ hybridization revealed EWSR1-WT1 gene rearrangement. Lung computer tomography and abdominal magnetic resonance imaging performed half a month later showed multiple solid nodules on the proximal septal surface of the right lung base, right posterior cardiac/right anterior inferior vena cava nodules, and multiple nodules in the abdominopelvic cavity, omenta, peritoneum, and around the liver or liver, all of which were considered as metastatic foci.

INTERVENTIONS AND OUTCOMES

Patient received 5 cycles of chemotherapy after surgery. The review results showed a smaller size than before. Currently, he continues to receive treatment.

LESSONS

The reported case has raised awareness of the importance of DSRCT in the treatment of chemotherapy, including its role in the differential diagnosis of abdominal tumors.

Intra-Abdominal Desmoplastic Small Round Cell Tumor (DSRCT) and the Role of Hyperthermic Intraperitoneal Chemotherapy (HIPEC): A Review

Desmoplastic small round cell tumor is a very rare and highly aggressive soft tissue sarcoma, usually presenting with multiple intra-abdominal tumors in young males. Patients present with advanced disease and the overall survival is dismal. Multiple studies report relatively favorable outcomes with multimodal treatment consisting of chemotherapy, surgery and radiotherapy. If resection is feasible, complete cytoreductive surgery is the cornerstone of surgical treatment. The benefit of hyperthermic intraperitoneal chemotherapy in addition to cytoreductive surgery is unclear, and few studies have evaluated this option. We sought to identify the role of hyperthermic intraperitoneal chemotherapy in patients with intra-abdominal desmoplastic small round cell tumor. Our review of the available literature revealed no clear survival benefit in performing hyperthermic intraperitoneal chemotherapy after cytoreductive surgery.

Lurbinectedin Inhibits the EWS-WT1 Transcription Factor in Desmoplastic Small Round Cell Tumor

Desmoplastic small round cell tumor (DSRCT) is a rare pediatric sarcoma with poor overall survival. This tumor is absolutely dependent on the continued expression and activity of its defining molecular lesion, the EWS-WT1 transcription factor. Unfortunately, the therapeutic targeting of transcription factors is challenging, and there is a critical need to identify compounds that inhibit EWS-WT1. Here we show that the compound lurbinectedin inhibits EWS-WT1 by redistributing the protein within the nucleus to the nucleolus. This nucleolar redistribution interferes with the activity of EWS-WT1 to reverse the expression of over 70% of the transcriptome. In addition, the compound blocks the expression of the EWS-WT1 fusion protein to inhibit cell proliferation at the lowest GI50 ever reported for this compound in any cell type. The effects occur at concentrations that are easily achievable in the clinic and translate to the in vivo setting to cause tumor regressions in multiple mice in a xenograft and PDX model of DSRCT. Importantly, this mechanism of nucleolar redistribution is also seen with wild-type EWSR1 and the related fusion protein EWS-FLI1. This provides evidence for a "class effect" for the more than 18 tumors driven by EWSR1 fusion proteins. More importantly, the data establish lurbinectedin as a promising clinical candidate for DSRCT.

Primary desmoplastic small round cell tumor of the submandibular gland: a case report and literature review

BACKGROUND

Desmoplastic small round cell tumor (DSRCT) is a sporadic, highly malignant tumor with a poor prognosis. The abdomen and pelvis have been reported as the primary localization sites. However, to the best of our knowledge, there are few reports on primary DSRCT in the submandibular gland.

CASE PRESENTATION

We report a case of a 26-year-old Chinese man with a mass in the right submandibular gland. Imaging studies showed a hypoechoic mass in the right submandibular region. Intraoperative pathology revealed that the tumor tissue was composed of small round tumor cells and a dense desmoplastic stroma. On immunostaining, the tumor cells showed markers of epithelial, mesenchymal, myogenic, and neural differentiation. The EWSR1 gene rearrangement was detected by fluorescence in situ hybridization. Based on the overall morphological features and immunohistochemical findings, a final diagnosis of DSRCT was made. The patient was treated with comprehensive anti-tumor therapy mainly based on radiotherapy and chemotherapy.

CONCLUSIONS

DSRCT is an uncommon malignant neoplasm with rare submandibular gland involvement. In this report, we have described a case of DSRCT in the submandibular gland and reviewed the literature on DSRCT over the past 5 years. Considering the importance of differential diagnosis between DSRCT, especially with rare extra-peritoneal involvement, and small round blue cell tumors, a full recognition of the clinicopathological features will help to better diagnose this neoplasm.

Desmoplastic Small Round Cell Tumor: A Review of Main Molecular Abnormalities and Emerging Therapy

Simple Summary

Desmoplastic small round cell tumor is a rare neoplasm with extremely aggressive behavior. Despite the multimodal treatment for newly diagnosed patients with chemotherapy, cytoreductive surgery and radiation, the cure rate is still low. For relapsed or progressive disease, there is limited data regarding second and third-line therapies. Novel agents have shown only modest activity. Recent molecular changes have been identified in this disease and this opens opportunities to be explored in future clinical trials.

Abstract

Desmoplastic small round cell tumor (DSRCT) is an extremely rare, aggressive sarcoma affecting adolescents and young adults with male predominance. Generally, it originates from the serosal surface of the abdominal cavity. The hallmark characteristic of DSRCT is the EWSR1–WT1 gene fusion. This translocation up-regulates the expression of PDGFRα, VEGF and other proteins related to tumor and vascular cell proliferation. Current management of DSRCT includes a combination of chemotherapy, radiation and aggressive cytoreductive surgery plus intra-peritoneal hyperthermic chemotherapy (HIPEC). Despite advances in multimodal therapy, outcomes remain poor since the majority of patients present disease recurrence and die within three years. The dismal survival makes DSRCT an orphan disease with an urgent need for new drugs. The treatment of advanced and recurrent disease with tyrosine kinase inhibitors, such as pazopanib, sunitinib, and mTOR inhibitors was evaluated by small trials. Recent studies using comprehensive molecular profiling of DSRCT identified potential therapeutic targets. In this review, we aim to describe the current studies conducted to better understand DSRCT biology and to explore the new therapeutic strategies under investigation in preclinical models and in early phase clinical trials.

Desmoplastic small round cell tumor is dependent on the EWS-WT1 transcription factor

Desmoplastic small round cell tumor (DSRCT) is a rare and aggressive soft-tissue malignancy with a poor overall survival and no effective therapeutic options. The tumor is believed to be dependent on the continued activity of the oncogenic EWS-WT1 transcription factor. However, the dependence of the tumor on EWS-WT1 has not been well established. In addition, there are no studies exploring the downstream transcriptional program across multiple cell lines. In this study, we have developed a novel approach to selectively silence EWS-WT1 without impacting either wild-type EWSR1 or WT1. We show a clear dependence of the tumor on EWS-WT1 in two different cell lines, BER and JN-DSCRT-1. In addition, we identify and validate important downstream target pathways commonly dysregulated in other translocation-positive sarcomas, including PRC2, mTOR, and TGFB. Surprisingly, there is striking overlap between the EWS-WT1 and EWS-FLI1 gene signatures, despite the fact that the DNA-binding domain of the fusion proteins, WT1 and FLI1, is structurally unique and classified as different types of transcription factors. This study provides important insight into the biology of this disease relative to other translocation-positive sarcomas, and the basis for the therapeutic targeting of EWS-WT1 for this disease that has limited therapeutic options.

Mini-Review on Targeted Treatment of Desmoplastic Small Round Cell Tumor

Desmoplastic small round cell tumor (DSRCT) is a devastating disease which most commonly affects adolescents, with a male predominance. Despite the best multimodality treatment efforts, most patients will ultimately not survive more than 3-5 years after diagnosis. Some research trials in soft-tissue sarcoma and Ewing sarcoma include DSRCT patients but few studies have been tailored to the specific clinical needs and underlying cytogenetic abnormalities characterizing this disease such as the typical EWSR1-WT1 gene fusion. Downstream activation of EWSR1-WT1 gene fusion includes signaling pathways of platelet-derived growth factor (PDGF), vascular endothelial growth factor (VEGF), and insulin growth factor (IGF)-1. Other biological pathways that are activated and expressed in DSRCT cells include endothelial growth factor receptor (EGFR), androgen receptor pathway, c-KIT, MET, and transforming growth factor (TGF) beta. Investigation of somatic mutations, copy number alterations (CNA), and chromosomes in DSRCT samples suggests that deregulation of mesenchymal-epithelial reverse transition (MErT)/epithelial-mesenchymal transition (EMT) and DNA damage repair (DDR) may be important in DSRCT. This mini review looks at known druggable targets in DSRCT and existing clinical evidence for targeted treatments, particularly multityrosine kinase inhibitors such as pazopanib, imatinib, and sorafenib alone or in combination with other agents such as mTOR (mammalian target of rapamycin) inhibitors. The aim is to increase shared knowledge about current available treatments and identify gaps in research to further efforts toward clinical development of targeted agents.

Desmoplastic small round cell tumour in the Afro-Caribbean population: case report with imaging findings

Desmoplastic Small Round Cell Tumour (DSRCT) is a rare malignancy that has only a few cases documented in the literature. We report a case of DSRCT in the abdomen and pelvis that was identified following ultrasound-guided biopsy of one of the numerous liver lesions seen on imaging in a 13-year-old Afro-Caribbean female with increased abdominal girth. The tumour was characterized by all routine imaging modalities available at the time. To our knowledge, this is the first reported and published case in the English speaking Caribbean. In the review of the literature, we correlate the imaging findings with previously reported cases. The diagnosis of DSRCT cannot be made solely using standard imaging techniques, but radiologists should be suspicious of DSRCT as a differential diagnosis in a young patient with increased abdominal girth, multiple liver and peritoneal deposits seen on imaging. Written informed consent for the case to be published (incl. images, case history, and data) was obtained from the parents of this patient for publication of this case report, including accompanying images.

Desmoplastic small round cell tumor: A nationwide study of a rare sarcoma

BACKGROUND AND OBJECTIVES

Desmoplastic small round cell tumor (DSRCT) is a rare peritoneal surface malignancy. Current research is limited by the scarcity of this disease.

METHODS

Patients with DSRCT were identified in the 2004-2014 NCDB. Factors affecting overall survival (OS) were assessed. Additionally, trends were examined based on the volume of cases treated at individual facilities.

RESULTS

A total of 125 patients were identified with a median age of 21 (IQR 15-27). Six had extra-abdominal disease and 15 (12%) had liver involvement. Median OS was 28 months. Systemic chemotherapy (HR 0.4, P = 0.015) and surgery (HR 0.6, P = 0.047) were associated with reduced mortality. For the 74 patients undergoing surgery, absence of liver involvement and receipt of postoperative chemotherapy were associated with improved OS on univariate analysis. On multivariable analysis, two factors approached significance: adjuvant chemotherapy was associated with a reduced risk of mortality (HR 0.3, P = 0.073) and residual macroscopic disease after resection correlated with increased risk of mortality (HR 5.3, P = 0.071). High-volume facilities (≥5 cases) experienced improved OS (median 59.1 vs 28.8 months), albeit not significantly (P = 0.135), compared to low-volume centers.

CONCLUSION

Despite multimodal treatment, DSRCT is associated with dismal outcomes. Facilities familiar with treating this uncommon disease may experience superior outcomes.

Genomic and Proteomic Alterations in Desmoplastic Small Round Blue-Cell Tumors

Purpose

Desmoplastic small round blue-cell tumors (DSRCTs) are sarcomas that contain the t(11;22) (p13;q12) translocation EWS-WT1 fusion protein. Because this is a rare tumor type, prospective clinical trials in DSRCT are challenging. Patients are treated in a manner similar to those with Ewing sarcoma; however, differences in prognosis and clinical presentation suggest fundamental differences in biology and potentially different therapeutic implications. This study aimed to characterize the molecular characteristics of DSRCT tumors to explore unique therapeutic options for this extremely rare and aggressive cancer type.

Methods

Thirty-five DSRCT tumors were assessed using next-generation sequencing, protein expression (immunohistochemistry), and gene amplification (chromogenic in situ hybridization or fluorescence in situ hybridization). Three patients had tumor mutational load, which was calculated as somatic nonsynonymous missense mutations sequenced with a 592-gene panel. Gene expression data were obtained for an additional seven DSRCT tumors. Molecular alterations were compared with 88 Ewing sarcomas.

Results

The most common alterations that distinguished DSRCTs from Ewing sarcoma included higher androgen receptor (AR), TUBB3, epidermal growth factor receptor, and TOPO2A expression. Independent analysis by RNA sequencing confirmed higher AR expression from an independent data set of EWS-WT1 fusion-positive DSRCTs compared with Ewing sarcoma and a pan-cancer analysis. DSRCTs had somatic mutations that were identified in TP53 and FOXO3, averaged five mutations per megabase, and no programmed death-ligand 1 expression was detected in any DSRCT samples.

Conclusion

The current analysis provides the first comparative analysis, to our knowledge, of molecular aberrations that distinguish DSRCT from Ewing sarcoma. High AR expression seems to be a defining event in these malignancies, and additional investigation of the responsiveness of AR inhibitors in this disease is encouraged.

High-Dose Chemotherapy with Stem Cell Rescue in Desmoplastic Small Round Cell Tumor: A Single-Institution Experience and Review of the Literature

Purpose

Desmoplastic small round cell tumor (DSRCT) is a rare cancer that predominantly affects males averaging 21 years of age at the time of diagnosis. We describe four cases from our institution and place them within the context of a comprehensive review of the literature.

Patients and Methods

Study population included any patient who received treatment at Children's Hospital at Montefiore (CHAM) with histologic diagnosis of DSRCT. A search of the electronic databases PubMed, Cochrane Central Register of Controlled Trials, MEDLINE, and EMBASE for the terms “desmoplastic” AND “small” AND “round” AND “cell” AND “tumor” was performed.

Results

One CHAM patient died of disease at 39 months, one patient has relapsed disease at 40 months, and two patients have no evidence of disease at 60 and 91 months. In the literature review, the 3-year OS was 36% and 5-year OS was 13%. There was a statistically significant difference in OS between no transplant and SCT in remission (p=0.004); however, there was no difference between no transplant and SCT not in remission (p=0.23).

Conclusion

Given the poor prognosis in DSRCT, this study supports further prospective research into the possible benefit of consolidation of autologous SCT in patients with DSRCT who are in remission, with the alternative inference that these patients in remission may fare well without SCT. Our retrospective review of the literature does not support SCT for patients who are not in remission.

Efficacy of ONC201 in Desmoplastic Small Round Cell Tumor

Desmoplastic Small Round Cell Tumor (DSRCT) is a rare sarcoma tumor of adolescence and young adulthood, which harbors a recurrent chromosomal translocation between the Ewing’s sarcoma gene (EWSR1) and the Wilms’ tumor suppressor gene (WT1). Patients usually develop multiple abdominal tumors with liver and lymph node metastasis developing later. Survival is poor using a multimodal therapy that includes chemotherapy, radiation and surgical resection, new therapies are needed for better management of DSRCT. Triggering cell apoptosis is the scientific rationale of many cancer therapies. Here, we characterized for the first time the expression of pro-apoptotic receptors, tumor necrosis-related apoptosis-inducing ligand receptors (TRAILR1-4) within an established human DSRCT cell line and clinical samples. The molecular induction of TRAIL-mediated apoptosis using agonistic small molecule, ONC201 in vitro cell-based proliferation assay and in vivo novel orthotopic xenograft animal models of DSRCT, was able to inhibit cell proliferation that was associated with caspase activation, and tumor growth, indicating that a cell-based delivery of an apoptosis-inducing factor could be relevant therapeutic agent to control DSRCT.

Desmoplastic Small Round Cell Tumor Treated with Cytoreductive Surgery and Hyperthermic Intraperitoneal Chemotherapy: Results of a Phase 2 Trial

BACKGROUND

Desmoplastic small round cell tumor (DSRCT) is a rare sarcoma that primarily affects adolescents and young adults. Patients can present with many peritoneal implants. We conducted a phase 2 clinical trial utilizing cytoreductive surgery and hyperthermic intraperitoneal chemotherapy (CRS-HIPEC) with cisplatin for DSRCT and pediatric-type abdominal sarcomas.

PATIENTS AND METHODS

A prospective cohort study was performed on 20 patients, who underwent CRS-HIPEC procedures, with cisplatin from 2012 to 2013. All patients were enrolled in the phase 2 clinical trial. Patients with extraabdominal disease and in whom complete cytoreduction (CCR0-1) could not be achieved were excluded. All outcomes were recorded.

RESULTS

Fourteen patients had DSRCT, while five patients had other sarcomas. One patient had repeat HIPEC. Patients with DSRCT had significantly longer median overall survival after surgery than patients with other tumors (44.3 vs. 12.5 months, p = 0.0013). The 3-year overall survival from time of diagnosis for DSRCT patients was 79 %. Estimated median recurrence-free survival (RFS) was 14.0 months. However, RFS for patients with DSRCT was significantly longer than for non-DSRCT patients (14.9 vs. 4.5 months, p = 0.0012). Among DSRCT patients, those without hepatic or portal metastases had longer median RFS than those with tumors at these sites (37.9 vs. 14.3 months, p = 0.02). In 100 % of patients without hepatic or portal metastasis, there was no peritoneal disease recurrence after CRS-HIPEC.

CONCLUSIONS

Complete CRS-HIPEC with cisplatin is effective in select DSRCT patients. DSRCT patients with hepatic or portal metastasis have poorer outcomes.

Pathology of retroperitoneal sarcomas: A brief review

Sarcomas represent a highly heterogeneous group of tumors as reflected in the significant overlap between their histologic phenotypes between the different types, posing diagnostic challenges for the pathologist. Definitive tumor classification is increasingly important because of prognostication and emergence of targeted therapies for some of the sarcoma types. In this review, we highlight pertinent pathologic and molecular aspects of sarcomas common in the retroperitoneum, relevant to the surgical oncologist.

Clinical Activity of Pazopanib in Patients with Advanced Desmoplastic Small Round Cell Tumor

BACKGROUND

Desmoplastic small round cell tumor (DSRCT) is an aggressive, often fatal soft tissue sarcoma that lacks an optimal salvage regimen. We retrospectively reviewed data from 29 pretreated DSRCT patients who received pazopanib at MD Anderson Cancer Center after failure of standard chemotherapies.

SUBJECTS, MATERIALS, AND METHODS

Medical records of patients treated from January 2012 to December 2016 were reviewed and regression analyses were performed. Median progression-free survival (PFS) and overall survival (OS) were estimated using the Kaplan-Meier method and differences in survival were assessed by a log-rank test. A landmark statistical analysis was used to assess OS at a predefined 12-week time point following pazopanib initiation.

RESULTS

The mean age at pazopanib treatment was 27.5 years (range, 6.3-50.1 years). According to RECIST 1.1 criteria, 16 patients (55%) had stable disease, 1 patient (3%) had partial response, 1 patient (3%) had complete response, and 11 patients (38%) had progressive disease. Estimated median PFS was 5.63 months (95% confidence interval [CI]: 3.23-7.47). Median OS was 15.7 months (95% CI: 10.3-32.4). As of December 2016, 11 patients (38%) were still alive, with a median follow-up time of 16.8 (range 3.8-30.1) months. Doses between 400 and 800 mg were included. Pazopanib was well tolerated and 23 (79%) of the patients continued it until progression or death, 4 discontinued because of side effects, and 2 were still on pazopanib at the time of data analysis.

CONCLUSION

In the largest study conducted to date in DSRCT, pazopanib was well tolerated and clinically active in heavily pretreated patients who otherwise lack good treatment options.

IMPLICATIONS FOR PRACTICE

Desmoplastic small round cell tumor (DSRCT) is a rare, extremely aggressive soft tissue sarcoma subtype that most commonly occurs in adolescent and young adult males. No DSRCT-specific therapies exist, and for lack of a better treatment approach, current therapies have relied upon U.S. Food and Drug Administration-approved drugs like pazopanib that exhibit clinical activity in other sarcoma subtypes. This article describes the largest experience to date using pazopanib as salvage treatment in heavily pretreated DSRCT patients. Pazopanib was well tolerated and clinically active, surpassing predefined metrics proposed by the European Organization for Research and Treatment of Cancer indicative of "active" sarcoma drugs (5.63 months progression-free survival [PSF], with 62% of the study population achieving progression-free survival at 12 weeks).

Clinical activity of eribulin in advanced desmoplastic small round-cell tumor

Desmoplastic small round-cell tumor is a rare but highly aggressive tumor occurring mainly in adolescents and young adults. Prolonged progression-free survival has been documented in patients who have undergone aggressive multimodality therapy - that is, multiagent intensive chemotherapy, debulking surgery, and radiation therapy. Eribulin is a microtubule-dynamics inhibitor, and it has recently been shown to be active in liposarcomas. In preclinical models, eribulin activities have also been shown to occur in Ewing's sarcoma cell lines, rhabdomyosarcomas and osteosarcomas. In this study, we report three cases of male patients suffering from desmoplastic small round-cell tumor and the clinical response to eribulin in two of them.

Desmoplastic Small Round Blue Cell Tumor: A Review of Treatment and Potential Therapeutic Genomic Alterations

Desmoplastic small round blue cell tumors (DSRCTs) originate from a cell with multilineage potential. A molecular hallmark of DSRCT is the EWS-WT1 reciprocal translocation. Ewing sarcoma and DSRCT are treated similarly due to similar oncogene activation pathways, and DSRCT has been represented in very limited numbers in sarcoma studies. Despite aggressive therapy, median survival ranges from 17 to 25 months, and 5-year survival rates remain around 15%, with higher survival reported among those undergoing removal of at least 90% of tumor in the absence of extraperitoneal metastasis. Almost 100% of these tumors contain t(11;22) (p13;q12) translocation, and it is likely that EWS-WT1 functions as a transcription factor possibly through WT1 targets. While there is no standard protocol for this aggressive disease, treatment usually includes the neoadjuvant HD P6 regimen (high-dose cyclophosphamide, doxorubicin, and vincristine (HD-CAV) alternating with ifosfamide and etoposide (IE) chemotherapy combined with aggressively attempted R0 resection). We aimed to review the molecular characteristics of DSRCTs to explore therapeutic opportunities for this extremely rare and aggressive cancer type.

Cytoreductive surgery and hyperthermic intraperitoneal chemotherapy combined with two-stage hepatectomy for multiple and bilobar desmoplastic small round cell tumor liver metastases

Desmoplastic small round cell tumor (DSRCT) is a rare mesenchymal tumor usually affecting young patients. Local dissemination is common, and liver is the most common site for extraperitoneal metastases. Multimodal management has been shown to be the most effective treatment. Some authors consider liver metastases especially bi-lobar disease as a contraindication for surgical resection. We present a case of a DSRCT with bi-lobar metastases in an adult patient who underwent multi-modal management along with hepatectomy. A 51-year-old man was found to have a large intraperitoneal mass with bi-lobar liver metastases during work up for new onset reflux and abdominal pain. Biopsy confirmed it as DSRCT. The patient was treated with multi-modal therapy including cytoreductive surgery (CRS), hyperthermic intraperitoneal chemotherapy (HIPEC), two-stage hepatectomy (TSHP) combined with (⁹⁰Y) Yittrium-90 radioembolization of the right hepatic lobe and systemic chemotherapy. The patient had a right-sided pleural empyema one month after the surgery for which he required right-sided video-assisted thoracoscopy and decortication. He remains disease free at 2 years follow-up. DSRCT with bi-lobar liver metastases are best managed with multimodal therapy. TSHP seems to be a feasible and safe option in selected cases, with a potentially good outcome.

Round Cell Tumors: Classification and Immunohistochemistry

Round cell tumors as the name suggest are comprised round cells with increased nuclear-cytoplasmic ratio. This group of tumor includes entities such as peripheral neuroectodermal tumor, rhabdomyosarcoma, synovial sarcoma, non-Hodgkin's lymphoma, neuroblastoma, hepatoblastoma, Wilms' tumor, and desmoplastic small round cell tumor. These round cells tumors are characterized by typical histological pattern, immunohistochemical, and electron microscopic features that can help in differential diagnosis. The present article describes the classification and explains the histopathology and immunohistochemistry of some important round cell tumors.

Role of Imaging in Peritoneal Surface Malignancies

Imaging plays a vital role in the evaluation of peritoneal malignancies. The presence of peritoneal metastases (PM) alters tumor staging, with direct implications in treatment choice and prognosis. Cytoreductive surgery (CRS) and Hyperthermic intraperitoneal chemotherapy (HIPEC) as a combined modality treatment have led to prolonged survival and even cure in selected patients with PM. Better outcomes are seen in patients with limited disease spread. Therefore, early diagnosis of peritoneal tumor seeding is essential. Despite significant advancement of technology, assessment of the origin of PM is often difficult, due partly to the complex peritoneal anatomy and partly due to the complex overlap of imaging features. Multidetector CT (MDCT) is the main stay due to its wide availbility, rapid evaluation, robust technique and good resolution. Imaging plays a vital role in selecting patients for the combined modality treatment. MRI is not as popular as CT due to limited availability, time required for the study and lack of experience with interpreting the results. PET-CT is useful in ruling out extra peritoneal disease and it is the CT component that is more reliable for predicting the disease extent. This article reviews the current use of various imaging modalities in various stages of treatment of patients with PM especially those undergoing CRS and HIPEC.

Clinical features and outcomes of 20 patients with abdominopelvic desmoplastic small round cell tumor

INTRODUCTION

Desmoplastic small round cell tumor (DSRCT) is a rare mesenchymal malignancy. We describe our experience with treating DSRCT at a large sarcoma referral center.

METHODS

A retrospective chart review was performed on DSRCT patients referred to our institution (1998-2014). Pathology specimens were reviewed to confirm the diagnosis. Clinical and imaging were extracted and summarized with descriptive statistics. Univariate analysis was performed to evaluate the association between patient, tumor, and treatment variables and overall survival (OS).

RESULTS

In this study cohort of 20 patients, median age at presentation was 29 y (range 18-43) and 90% were male. Fifty-five percent presented with metastasis. Patients underwent chemotherapy (n = 20), radiation therapy (n = 3), and cytoreductive surgery (CRS) (n = 5). Median OS was 22 m (interquartile range: 12-28 m). Five-year OS rate was 20%. Extra-abdominal metastasis was associated with a higher hazard ratio (HR) of mortality (HR: 3.1, 95% C.I. 1.0-9.4, p = 0.04), while CRS improved OS (HR: 0.1, 95% C.I. 0.03-0.7, p = 0.02).

CONCLUSIONS

Despite aggressive treatment, less than half of the patients were dead of DSRCT within 2 years of presentation. Although a select group of patients who underwent CRS had improved OS, novel treatments are urgently needed.

Malignant tumors of the liver in children

This article aims to give an overview of pediatric liver tumors; in particular of the two most frequently occurring groups of hepatoblastomas and hepatocellular carcinomas. Focus lays on achievements gained through worldwide collaboration. We present recent advances in insight, treatment results, and future questions to be asked. Increasing international collaboration between the four major Pediatric Liver Tumor Study Groups (SIOPEL/GPOH, COG, and JPLT) may serve as a paradigm to approach rare tumors. This international effort has been catalyzed by the Children's Hepatic tumor International Collaboration (CHIC) formation of a large collaborative database. Interrogation of this database has led to a new universal risk stratification system for hepatoblastoma using PRETEXT/POSTTEXT staging as a backbone. Pathologists in this international collaboration have established a new histopathological consensus classification for pediatric liver tumors. Concomitantly there have been advances in chemotherapy options, an increased role of liver transplantation for unresectable tumors, and a web portal system developed at www.siopel.org for international education, consultation, and collaboration. These achievements will be further tested and validated in the upcoming Paediatric Hepatic International Tumour Trial (PHITT).

Desmoplastic small round cell tumor: postoperative retroperitoneal mass

We describe the case of a 14-year-old boy who presented with a large, 17.6-cm retroperitoneal mass, along with multiple metastases, and was diagnosed with desmoplastic small round cell tumor. After initial chemotherapy, he underwent gross total resection with a positive margin. On postoperative radiation planning computed tomography, a 6.8-cm heterogeneous mass was noted in the surgical bed. Given the tumor's aggressive nature and positive surgical margins, there was real concern for recurrent disease. Further evaluation with magnetic resonance imaging elucidated that the mass consisted of simple fluid and fat, without contrast enhancement, suggesting a postoperative fluid collection. He was able to continue with adjuvant treatment as planned. This case example illustrates that even large postoperative heterogeneous masses may still be related to postoperative fluid collection in patients with aggressive tumor. However, it is important to rule out recurrent disease before starting adjuvant therapy given improved outcomes with gross total resection in desmoplastic small round cell tumor.

Clinical Characteristics and Outcomes of Pediatric Patients with Desmoplastic Small Round Cell Tumor

Desmoplastic small round cell tumor (DSRCT) is a rare malignancy that typically affects pediatric and young adult patients. There are limited data on the clinical features of pediatric DSRCT. We selected patients aged 0-21 years reported to the Surveillance, Epidemiology and End Results Program from 1991-2011. We estimated overall survival using Kaplan-Meier approaches and compared outcomes using the log rank test. The median age of the 95 pediatric patients was 15.3 years (range: 0-21). The majority of tumors originated in the abdomen and pelvis (84.4%) and the majority of patients had distant metastasis (72.6%). A minority of patients received radiation (34%). Overall survival at 5 years was poor (18.1%; 95% confidence interval 10.1-27.9%). Radiation therapy was associated with superior survival. Pediatric patients with DSRCT have significant disease burden. Outcomes for children are poor, though patients selected for radiation appear to have improved survival.

Desmoplastic small round cell tumor 20 years after its discovery

Desmoplastic small round cell tumor (DSRCT) was proposed as a distinct disease entity by William L Gerald and Juan Rosai in 1991. Over 850 patients have been reported in the medical literature. A specific translocation, t(11;22)(p13;q12), is seen in almost all cases, juxtaposing the EWS gene to the WT1 tumor suppressor gene. DSRCT is composed of nests of small round cells with polyphenotypic differentiation, typically a mixture of epithelial, mesenchymal and neural features, surrounded by a prominent desmoplastic stroma. DSRCT has a predilection for adolescent and young adult males, and primarily involves the abdominal cavity and pelvis. Survival is low despite their initial response to multimodal treatment. Most patients relapse with disseminated disease that is unresponsive to further therapy.

Cytoreductive Surgery (CRS) and Hyperthermic Intraperitoneal Chemotherapy (HIPEC) in Pediatric Ovarian Tumors: A Novel Treatment Approach

PURPOSE

Cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC) have been used in adults with ovarian carcinoma proving overall survival benefit in randomized trials, but measured in months. Diffuse peritoneal disease from pediatric type ovarian tumors is rare. We applied CRS and HIPEC to pediatric girls with diffuse peritoneal disease as part of a clinical trial.

METHODS

In all patients complete cytoreduction was followed by HIPEC using 100 mg/m2 of cisplatin for 90 min in a closed technique. All received neoadjuvant chemotherapy. Patients with disease outside of the abdominal cavity were excluded.

RESULTS

Of 101 pediatric CRS and HIPEC operations, 8 had ovarian primary tumors and multifocal peritoneal disease. There were three yolk sac tumors (germ cell, mixed teratoma), one Sertoli–Leydig, one PNET of the ovary, one choriocarcinoma, one juvenile granulosa cell tumor and one adenocarcinoma. Age ranged 4–18 years. Three of the 8 (37 %) recurred and died. The remaining 63 % are disease free 2–6 years post HIPEC. Overall survival and relapse-free survival in this cohort was 64 and 62 %, respectively [CI 0.64 (0.34, 1); 0.62 (0.37, 1)].

CONCLUSIONS

This is the first report of CRS and HIPEC in pediatric ovarian tumors. HIPEC may be effective in pediatric-type ovarian tumors. More study is needed in a larger cohort.

A Rare Case of Metastatic Desmoplastic Small Round Cell Tumour: Diagnosis and Management

A 26-year-old male without any significant past medical history presented to the hospital with shortness of breath, cough, pleuritic chest pain, and weight loss for the past 3 months. On chest CT, he was found to have extensive mediastinal and hilar lymphadenopathy and multiple pulmonary nodules. On physical examination, a right groin mass was noted which had been slowly growing for the past 2 years. Ultrasound of the groin showed complex solid mass with internal vascular channels. CT guided biopsy of the mass showed desmoplastic small round cell tumour. His hospital course was complicated by hypoxic respiratory failure requiring emergent intubation and ICU admission where he completed one cycle of vincristine, cyclophosphamide, and doxorubicin with subsequent improvement, followed by extubation. His condition continued to improve after second cycle of chemotherapy and he was ultimately discharged in a stable condition to continue outpatient chemotherapy after a 2-month inpatient stay.

Desmoplastic small round cell tumor: A case report of a rare differential diagnosis of solid tumors of the pleura

Desmoplastic small round cell tumor (DSRCT) presents as a rare separate clinical pathological entity, and pleural DSRCT is very rare. Following review of the English literatures it was revealed that, to date, <15 cases of primary DSRCT of the pleura have been reported worldwide. Among these, there are few computed tomography (CT) findings of pleural DSRCT which have previously been described in detail. The present study reports a pathologically proven case of pleural DSRCT, with varying contrast CT findings in a 72-year-old female, which appeared as a large (12.0×10.0×6.5 cm), smooth, oval mass in the left lower thorax with slight-moderate uniform enhancement on contrast-enhanced CT. To the best of our knowledge, the present report is the first to describe the large solid-tumor pattern and the patient is the eldest reported case of pleural DSRCT.

A Case of Desmoplastic Small Round Cell Tumor

Desmoplastic small round cell tumor is a rare, aggressive tumor primarily affecting young males. It is considered a childhood cancer, and is characterized by a unique chromosomal translocation which leads to failure to suppress tumor growth. It is classified as a soft tissue sarcoma, sharing some features with other small round cell tumors such as Ewing's Sarcoma and primitive neuroectodermal tumor. Typical imaging findings include multiple heterogeneous, lobular abdominal masses, which can grow very large. Often there is a dominant mass with additional peritoneal, omental, retroperitoneal and retrovesical masses. Prognosis is relatively poor with a 3 year survival rate of 50% in those treated aggressively with surgical resection, chemotherapy, and radiation therapy. The clinical presentation, imaging characteristics and pathology are discussed in regards to a recent case.

Requirement for novel surgical and clinical protocols for the treatment of desmoplastic small round cell tumor: A report of two cases and a review of the literature

Desmoplastic small round cell tumor (DSRCT) is a rare and highly aggressive neoplasm that was initially described in 1989. DSRCT predominantly affects young men and typically occurs in the intra-abdominal area. The present study describes the cases of two patients with DSRCT. The first patient was a 23-year-old male who presented with abdominal pain in the right flank, coupled with difficulty urinating and bowel dysfunction. The second patient was 12-year-old female who presented with abdominal pain, emesis and loss of appetite. A computed tomography scan of the abdomen revealed the presence of an extensive pelvic mass in each patient, however, a visceral origin was not clearly identifiable in the first patient. In the second patient, a large soft-tissue tumor was located posterior to the pancreatic tail and the stomach, with no anatomical line visible between the stomach and splenic vein. Ultrasound-guided biopsy in the first patient and videolaparoscopy in the second patient followed by immunohistochemical analysis clarified the presence of a malignant neoplasm composed of small, blue, round cells. Due to right ureter involvement and hydronephrosis in the first patient, a treatment strategy of surgical debulking of the tumor was selected. The surgical procedure involved en bloc resection of the lesion associated with a pelvic peritonectomy, followed by post-operative radiotherapy. However, the second patient exhibited extensive disease, therefore, a chemotherapeutic protocol of vincristine, doxorubicin and cyclophosphamide, as well as radiation therapy, was scheduled. Disease relapse was observed in the abdominal cavity of the first patient after one year, while the second patient remains asymptomatic. Following analysis of present two cases, it was concluded that aggressive treatment regimens may induce tumor regression. However, relapse of the disease is frequent and long-term survival is rare with the currently available therapeutic strategies.

Peritonectomy and hyperthermic intraperitoneal chemotherapy as treatment for desmoplastic small round cell tumour

INTRODUCTION

The St George Hospital specialises in peritonectomy and hyperthermic intraperitoneal chemotherapy (HIPEC) for treatment of intra-abdominal malignancies. Despite performing around 800 peritonectomy and HIPEC procedures, we have rarely encountered desmoplastic small round cell tumours (DSRCT). We present our experiences with DSRCT, and propose peritonectomy and HIPEC as a treatment option for DSRCT.

PRESENTATION OF CASE

This is a case series of 3 cases. The first case was a 26-year-old male who presented with appendicitis which we diagnosed as DSRCT and treated with peritonectomy and HIPEC. The second case was a 14-year-old male referred to our centre for peritonectomy and HIPEC after initial presentation with a pelvic mass and treatment with chemotherapy. The third case was a 21-year-old male referred to our centre for peritonectomy and HIPEC for recurrent DSRCT after previously being treated with neoadjuvant chemotherapy and surgery without HIPEC.

DISCUSSION

DSRCT is a rare, almost exclusively intra-abdominal malignancy, which predominantly affects young males. Survival prognosis remains poor in DSRCT despite conventional treatment with surgery, chemotherapy and radiotherapy; however, HIPEC has offered promising survival results. Our recurrences with peritonectomy and HIPEC at 6 months and 15 months are comparable with the literature of 8.85 months.

CONCLUSION

In our experience, patients with DSRCT who present with nodal involvement or recurrent disease tend to recur early despite treatment with peritonectomy and HIPEC. Longer term follow up of our patients and future studies involving HIPEC in DSRCT would be useful in assessing long-term clinical outcomes and survival.

Novel secondary somatic mutations in Ewing's sarcoma and desmoplastic small round cell tumors

BACKGROUND

Ewing's sarcoma (ES) and desmoplastic small round cell tumors (DSRCT) are small round blue cell tumors driven by an N-terminal containing EWS translocation. Very few somatic mutations have been reported in ES, and none have been identified in DSRCT. The aim of this study is to explore potential actionable mutations in ES and DSRCT.

METHODOLOGY

Twenty eight patients with ES or DSRCT had tumor tissue available that could be analyzed by one of the following methods: 1) Next-generation exome sequencing platform; 2) Multiplex PCR/Mass Spectroscopy; 3) Polymerase chain reaction (PCR)-based single- gene mutation screening; 4) Sanger sequencing; 5) Morphoproteomics.

PRINCIPAL FINDINGS

Novel somatic mutations were identified in four out of 18 patients with advanced ES and two of 10 patients with advanced DSRCT (six out of 28 (21.4%));KRAS (n = 1), PTPRD (n = 1), GRB10 (n = 2), MET (n = 2) and PIK3CA (n = 1). One patient with both PTPRD and GRB10 mutations and one with a GRB10 mutation achieved a complete remission (CR) on an Insulin like growth factor 1 receptor (IGF1R) inhibitor based treatment. One patient, who achieved a partial remission (PR) with IGF1R inhibitor treatment, but later developed resistance, demonstrated a KRAS mutation in the post-treatment resistant tumor, but not in the pre-treatment tumor suggesting that the RAF/RAS/MEK pathway was activated with progression.

CONCLUSIONS

We have reported several different mutations in advanced ES and DSRCT that have direct implications for molecularly-directed targeted therapy. Our technology agnostic approach provides an initial mutational roadmap used in the path towards individualized combination therapy.

Testicular desmoplastic small round cell tumor: a case report and review of literature

Background

Desmoplastic small round cell tumor (DSRCT) is an uncommon and highly aggressive malignancy with undetermined histogenesis and poor prognosis. To date, no case of testicular DSRCT has been reported in the literature.

Case

A 42-year-old Chinese man presented with painless swelling of his left testis and a painless palpable nodule in his left inguinal region. Computed tomography showed a solid mass in the left testis and multiple metastases in the body. Laboratory tests gave no abnormal results. Left radical orchiectomy was performed, and histopathological and molecular pathological examination showed typical features of DSRCT. Six cycles of chemotherapy were administrated after the operation, leading to partial remission. Postoperative 9-month follow-up indicated no progression.

Desmoplastic small round cell tumor: a rare cause of a progressive brachial plexopathy

INTRODUCTION

Desmoplastic small round cell tumor (DSRCT) is an uncommon, embryonic-type neoplasm, typically presenting as an abdominal mass in young men. A single case of DSRCT arising in the peripheral nervous system has been reported previously.

METHODS

The clinical course, imaging, electrophysiological, intraoperative, histopathological, molecular findings, and postoperative follow-up are reported.

RESULTS

A 43-year-old man presented with slowly progressive right brachial plexopathy. Magnetic resonance imaging revealed an enlarged medial cord with heterogeneous contrast enhancement. Histology showed a "small round cell" neoplasm with a polyphenotypic immunoprofile, including epithelial and mesenchymal markers. A pathognomonic fusion of Ewing sarcoma breakpoint region 1 and Wilms tumor 1 genes (EWSR1/WT1) was present. Treatment involved gross total excision and local radiotherapy.

CONCLUSIONS

Our findings confirm the occurrence of DSRCT as a primary peripheral nerve tumor. Despite its usually very aggressive clinical course, prolonged recurrence-free survival may be reached. Histomorphology and immunoprofile of DSRCT may lead to misdiagnosis as small cell carcinoma.

Clinical and computed tomography features of adult abdominopelvic desmoplastic small round cell tumor

To investigate the clinical and computed tomography (CT) features of desmoplastic small round cell tumor (DSRCT), we retrospectively analyzed the clinical presentations, treatment and outcome, as well as CT manifestations of four cases of DSRCT confirmed by surgery and pathology. The CT manifestations of DSRCT were as follows: (1) multiple soft-tissue masses or diffuse peritoneal thickening in the abdomen and pelvis, with the dominant mass usually located in the pelvic cavity; (2) masses without an apparent organ-based primary site; (3) mild to moderate homogeneous or heterogeneous enhancement in solid area on enhanced CT; and (4) secondary manifestations, such as ascites, hepatic metastases, lymphadenopathy, hydronephrosis and hydroureter. The prognosis and overall survival rates were generally poor. Commonly used treatment strategies including aggressive tumor resection, polychemotherapy, and radiotherapy, showed various therapeutic effects. CT of DSRCT shows characteristic features that are helpful in diagnosis. Early discovery and complete resection, coupled with postoperative adjuvant chemotherapy, are important for prognosis of DSRCT. Whole abdominopelvic rather than locoregional radiotherapy is more effective for unresectable DSRCT.

Desmoplastic small round cell tumor: a case report and review of the literature

Desmoplastic small round cell tumor is a rare malignant tumor that has a poor prognosis. It affects predominantly young males. In the current report, a 14-year-old male patient was admitted to the hospital for evaluation of abdominal distension, and abdominal pain. Imaging examination revealed a high prevalence of multiple intraperitoneal and liver parenchymal cystic and solid tumors. After an explorative surgery, the pathological findings confirmed the presentation of desmoplastic small round cell tumor. Diagnosis of desmoplastic small round cell tumor could easily have been overlooked since there was no specific evidence for this condition available in the clinical and imaging examinations. In the present study, ultrasound examination detected solid cystic masses, which suggested the presence of necrosis and hemorrhage. Immunohistochemistry and cytogenetic studies confirmed the diagnosis of desmoplastic small round cell tumor in this patient.

Complete cytoreduction and HIPEC improves survival in desmoplastic small round cell tumor

BACKGROUND

Desmoplastic small round cell tumor (DSRCT) is a rare tumor of adolescents and young adults. Less than 100 cases per year are reported in North America. Extensive peritoneal metastases are characteristic of this disease. We performed cytoreductive surgery and hyperthermic peritoneal perfusion with chemotherapy (HIPEC) using cisplatin (CDDP) for DSRCT.

METHODS

A retrospective cohort study was performed on 26 pediatric and adult patients who underwent cytoreduction/HIPEC using CDDP for DSRCT at a single cancer center. Neoadjuvant chemotherapy, adjuvant chemotherapy, and postoperative enteral nutrition were given to all patients. Postoperative radiation therapy was given to most patients. Follow-up was from 6 months to 6 years. Outcome variables were evaluated for disease-free and overall survival (OS).

RESULTS

Five patients (19 %) were less than 12 years of age at surgery. Patients who had disease outside the abdomen at surgery had a larger risk of recurrence or death than those who did not (p = 0.0158, p = 0.0393 time from surgery to death respectively). Age, liver metastasis, and peritoneal cancer index level did not significantly predict disease-free or OS. Patients who had CR0 or CR1 and HIPEC had significantly longer median survival compared with patients who had HIPEC and CR2 cytoreduction (63.4 vs. 26.7 months).

CONCLUSIONS

HIPEC may be an effective therapy for children and young adults with DSRCT. Patients with DSRCT require complete cytoreduction before HIPEC to optimize outcome. Patients with DSRCT and disease outside the abdomen at the time of surgery do not benefit from HIPEC.

Neural cell adhesion molecules belonging to the family of leucine-rich repeat proteins

Leucine-rich repeats (LRRs) are motifs that form protein-ligand interaction domains. There are approximately 140 human genes encoding proteins with extracellular LRRs. These encode cell adhesion molecules (CAMs), proteoglycans, G-protein-coupled receptors, and other types of receptors. Here we give a brief description of 36 proteins with extracellular LRRs that all can be characterized as CAMs or putative CAMs expressed in the nervous system. The proteins are involved in multiple biological processes in the nervous system including the proliferation and survival of cells, neuritogenesis, axon guidance, fasciculation, myelination, and the formation and maintenance of synapses. Moreover, the proteins are functionally implicated in multiple diseases including cancer, hearing impairment, glaucoma, Alzheimer's disease, multiple sclerosis, Parkinson's disease, autism spectrum disorders, schizophrenia, and obsessive-compulsive disorders. Thus, LRR-containing CAMs constitute a large group of proteins of pivotal importance for the development, maintenance, and regeneration of the nervous system.

Analysis of clinicopathological features and prognostic factors of desmoplastic small round cell tumor

Desmoplastic small round cell tumor (DSRCT) is a relatively uncommon and highly aggressive malignancy in young males. It is associated with a poor outcome, due in part to missed diagnosis. To characterize the clinical pathological features of DSRCT in Chinese patients and to find out the characteristics of treatment and prognostic factors, the authors collected and analyzed the clinical information of 48 cases. A total of 48 cases of DSRCT between March 1995 and March 2012 were retrospectively reviewed and analyzed. The clinical information, histological results and survival data of the patients were collected. Median age was 26.96 ± 14.09 years with a range of 6-66 years. Thirty-three patients (68.75%) were seen before 30 years old, and 15 patients (31.25%) were diagnosed after 30 years old. The male-to-female ratio is 3.36 :1. Among them, 37 cases presented with tumors in the abdominal or pelvic cavity; the other 11 cases had extra-abdominal tumors. The most common symptoms were abdominal pain (19/48, 39.58%) and palpable mass (12/48, 25.00%). The percentage of patients received surgery, complete surgery, and chemotherapy was 79.17%, 37.50%, and 52.08%, respectively. Median follow-up duration was 2.67 years. Median overall survival for all patients was 24.33 months (95% CI: 9.74-38.92 months) and median event-free survival for all patients was 8.00 months (95% CI: 5.13-10.89 months). Univariate analysis revealed that surgery, effective debulking surgery, chemotherapy and any two or more combined therapeutics were significant prognostic factors for longer overall survival (p < 0.05). Cox regression analysis showed complete surgery was an independent prognostic factor. Standard therapy for DSRCT consists of combination of surgical resection and postoperative chemotherapy. Complete surgery is an independent prognostic factor and should be further investigated.

Desmoplastic small round cell tumor of stomach

Desmoplastic small round cell tumor (DSRCT) is an extremely uncommon, highly aggressive, and malignant mesenchymal neoplasm of undetermined histogenesis. Less than 200 case reports have been documented in literature so far. Herein, we report a 26-year-old otherwise healthy female patient who presented with a 1-month history of epigastric pain. On physical examination, a palpable, slightly mobile, and tender epigastric mass was detected. All laboratory tests were normal. A chest, abdominal, and pelvic contrast-enhanced computed tomography (CT) scans showed a 3.8 × 7.2 × 8.7 cm ill-defined mass, involving gastric fundus and extending into gastric cardia and lower gastroesophageal junction. It was associated with multiple enlarged gastrohepatic lymph nodes; the largest measured 1.2 cm. There was no evidence of ascites or retroperitoneal or mesenteric lymphatic metastases. Patient underwent total gastrectomy with D2 lymphadenectomy, splenectomy, and antecolic Roux-en-Y esophagojejunal anastomosis. Histopathological examination revealed coexpression of mesenchymal, epithelial, and neural markers. The characteristic chromosomal translocation (t(11; 22)(p13; q12)) was demonstrated on fluorescence in situ hybridization (FISH) technique. Diagnosis of DSRCT of stomach was confirmed. Patient received no postoperative radiotherapy or chemotherapy. A postoperative 3-month followup failed to show any recurrence. In addition, a literature review on DSRCT is included.

Primary primitive neuroectodermal tumor of the cervix

Primary primitive neuroectodermal tumors (PNETs) are rare and high-grade malignant tumors that mostly occur in children and young adults. The most common sites are the trunk, limbs, and retroperitoneum. Herein, we present a case of a PNET involving the cervix uteri in a 27-year-old woman. The lesion showed characteristic histologic features of a PNET and was positive for the immunohistochemical markers cluster of differentiation (CD) 99, vimentin, neuron-specific enolase, neural cell adhesion molecule 1 (CD56), and CD117 (c-kit), further defining the tumor while helping to confirm PNET. The clinical Stage IIIB tumor was treated with chemotherapy and radiotherapy.