Molecular biology of the Ewing's sarcoma/primitive neuroectodermal tumor family

Radiologic and clinicopathologic findings of peripheral primitive neuroectodermal tumors

BACKGROUND

Primitive neuroectodermal tumors (PNETs) constitute a rare type of malignant neuroectodermal tumors that have chromosomal translocations identical to Ewing's sarcoma (ES), and the characteristics of this disease remain unclear.

PURPOSE

To describe the clinical, radiological, and pathological features of peripheral PNETs (pPNETs) to enhance their recognition.

MATERIAL AND METHODS

The clinical, imaging, and pathologic findings of 35 patients with pPNETs were retrospectively reviewed, all being confirmed by biopsy or surgical pathology. All 35 patients had preoperative computed tomography (CT) examinations; 10 patients had preoperative magnetic resonance imaging (MRI) studies.

RESULTS

Of 35 pPNET patients, 54.3% had a primary tumor in soft tissue, the others in bone. On plain CT images, 33 lesions demonstrated heterogeneous hypodense masses with multiple lamellar lower density, and with osteolytic destruction if the tumor originated in bone. Calcification was only found in five lesions arising in soft tissue. All lesions enhanced heterogeneously with varying areas of cystic changes, and all lesions in bone and 52.6% of lesions in soft tissue showed ill-defined margins after contrast administration. On MRI, these tumors appeared in conjunction with osteolytic bone destruction and irregular soft tissue masses iso- to hypointense to skeletal muscle on T1-weighted images and showed heterogeneously high intensity on T2-weighted images. All lesions enhanced heterogeneously with cystic changes. Homer-Wright rosettes were observed in 15 lesions, and 97.1% lesions were positive for CD99 in histopathological results.

CONCLUSION

pPNETs can involve any part of the body, and a large, ill-defined, aggressive soft tissue mass and heterogeneous enhancement with or without osteolytic bone destruction on CT or MR images could suggest the diagnosis.

Primary Multiple Pulmonary Primitive Neuroectodermal Tumor: Case Report and Literature Review

Primitive neuroectodermal tumors (PNETs) arising directly from the lung are extremely rare but particularly aggressive neoplasms. Although thoracic PNET usually develops on the chest wall, there have been reports of primary Ewing sarcoma/PNET of the lung.We present the case of a 16-year-old male with PNET diagnosed following histologic and immunohistochemical examination of a video-assisted thoracic surgical biopsy. As typically occurring for these tumors, the diagnosis was initially delayed in our patient and prognosis was poor despite aggressive surgical resection and postoperative chemotherapy. We attempted to explore the use of targeted pharmacotherapy through high-throughput sequencing in this case. We found that this treatment using Avastin and Cetuximab could provide a new therapeutic direction for PNET.PNENTs arising from the lung parenchyma without pleural or chest wall involvement are extremely rare. Although uncommon, if the pathological features are similar to Ewing sarcoma, PNENTs should be kept in mind, and the target therapy may be a potent treatment for this disease.

Primitive Neuroectodermal Tumor of the Pancreas: A Case Report and Review of the Literature

Primitive neuroectodermal tumors (PNETs) are presented as rare malignant neoplasms. In unusual cases, those neoplasms may arise in solid organs containing neuroendocrine cells, such as the pancreas. Herein the case of a 28-year-old patient that underwent gastroduodenopancreatectomy after the diagnosis of a huge mass (PNET) located in both head and body of the pancreas is reported. This is the 19th case of pancreatic PNET reported in literature.

Radiological and clinical findings of osseous peripheral primitive neuroectodermal tumors

Peripheral primitive neuroectodermal tumor (pPNET) is a rare and highly malignant undifferentiated type of tumor. The aim of the present study was to analyze the computed tomography (CT), magnetic resonance imaging (MRI) and clinical findings of osseous pPNET. The present study retrospectively analyzed the clinical data and CT findings from 15 patients with osseous pPNET; the MRI findings from 11 of these 15 patients were confirmed by histopathological examination. The 15 patients included 9 men and 6 women. The mean patient age was 29 years (range, 16-64 years) and 11 cases were aged <30 years. A CT scan was performed in 15 cases and the findings included a lytic lesion (13 cases), a lytic lesion with irregular sclerosis and dilation (2 cases), a soft tissue mass (15 cases), calcification (2 cases) and periosteal reaction (5 cases). A total of 9 cases of soft tissue mass were heterogeneous, with different sizes of lower-density necrotic areas. An enhanced MRI scan was performed in 11 cases. On T1-weighted images (WI), the soft tissue mass was isointense (8 cases) and marginally hyperintense (3 cases). On T2WI, aggressive soft tissue masses were heterogeneous iso- or hyperintense (11 cases). On contrast-enhanced T1WI, marked heterogeneous enhancement was present in 10 cases and intermediate heterogeneous enhancement in 1 case. The results indicated that osseous pPNET mainly affects male adolescents and young adults. The CT findings of osseous pPNET were destructive lesions with a soft tissue mass and, occasionally, with periosteal reaction. The tumor was often isodense, with patchy hypodense areas. Tumor calcification was uncommon. The MRI findings were those of an aggressive soft tissue mass exhibiting isointensity on T1WI and iso- or hyperintensity on T2WI, with marked heterogeneous enhancement. Although the imaging characteristics of pPNETs may be non-specific, CT and MRI may be useful in delineating the extent of the tumor, identifying distant metastases, predicting resectability and monitoring treatment.

An Oral Formulation of YK-4-279: Preclinical Efficacy and Acquired Resistance Patterns in Ewing Sarcoma

Ewing sarcoma is a transcription factor-mediated pediatric bone tumor caused by a chromosomal translocation of the EWSR1 gene and one of several genes in the ETS family of transcription factors, typically FLI1 or ERG. Full activity of the resulting oncogenic fusion protein occurs only after binding RNA helicase A (RHA), and novel biologically targeted small molecules designed to interfere with that interaction have shown early promise in the preclinical setting. Herein, we demonstrate marked preclinical antineoplastic activity of an orally bioavailable formulation of YK-4-279 and identify mechanisms of acquired chemotherapy resistance that may be exploited to induce collateral sensitivity. Daily enteral administration of YK-4-279 led to significant delay in Ewing sarcoma tumor growth within a murine model. In advance of anticipated early-phase human clinical trials, we investigated both de novo and acquired mechanism(s) by which Ewing sarcoma cells evade YK-4-279-mediated cell death. Drug-resistant clones, formed by chronic in vitro exposure to steadily increased levels of YK-4-279, overexpressed c-Kit, cyclin D1, pStat3(Y705), and PKC isoforms. Interestingly, cross-resistance to imatinib and enzastaurin (selective inhibitors of c-Kit and PKC-β, respectively), was observed and the use of YK-4-279 with enzastaurin in vitro led to marked drug synergy, suggesting a potential role for combination therapies in the future. By advancing an oral formulation of YK-4-279 and identifying prominent mechanisms of resistance, this preclinical research takes us one step closer to a shared goal of curing adolescents and young adults afflicted by Ewing sarcoma.

Targeted therapies for advanced Ewing sarcoma family of tumors

The prognosis of adolescent and young adult patients battling metastatic Ewing sarcoma family of tumors (ESFT) remains less than 30% despite the development of systemic therapies. In the era of personalized medicine, novel molecular targets have been tested in preclinical or clinical settings in ESFT. In this review, we focus on early clinical and translational research that identified multiple molecular targets, including IGF-1R; mTOR; tyrosine kinase inhibitors; EWS-FLI1-related targets, and others. Overall, novel targeted therapies demonstrated modest efficacy; however pronounced and durable antineoplastic responses have been observed in small subsets of treated patients, for example with IGF-1R antibodies. Identifying outcome-predicting biomarkers and overcoming treatment resistance remain major challenges. Due to the rarity of ESFT, multi-institutional collaboration efforts of clinicians, basic and translational scientists are needed in order to understand biology of therapeutic response or resistance, which can lead to development of novel therapeutic methods and improved patient outcomes.

Surgically treated patients with axial and peripheral Ewing's sarcoma family of tumours: A population based study in Finland during 1990-2009

BACKGROUND

The surgical treatment of Ewing's sarcoma family tumours (ESFTs) is challenging especially with axial tumours. The aim of the study was to analyse surgical treatment and outcome in a nationwide, population-based material consisting of surgically treated axial and peripheral ESFTs of bone and soft tissue.

METHODS

The data were collected from the Finnish National Cancer Registry and the medical records of patients diagnosed during 1990-2009. Fifty-seven patients with surgically treated ESFTs were included, 22 with an axial and 35 with a peripheral primary tumours. The surgical treatment, its complications, survival and prognostic factors were analysed.

RESULTS

Fifty-four patients underwent surgery with a curative intent and three underwent de-bulking operations. Bone reconstruction was performed in six patients with an axial and 15 with a peripheral tumour. Positive resection margins were associated with a worse five-year local relapse-free survival (33% vs. 84% for those with resection margins free of tumour cells, p = 0.003). The five-year sarcoma-specific survival was affected only by an axial location of the primary (61% vs. 89% for those with a peripheral tumour, p = 0.031). The late complications were mainly associated with bone reconstruction and more frequent among patients with a peripheral compared to an axial tumour (p = 0.031).

CONCLUSIONS

In the treatment of ESFTs, achieving adequate resection margins is crucial to avoid local relapses. Surgical complications are common particularly with bone reconstruction.

Ewing sarcoma of the liver with multilocular cystic mass formation: a case report

Background

Ewing sarcoma is a rare tumor that occurs commonly in the long bones of children or adolescents that can also arise in soft tissues including the extremities, retroperitoneum, chest wall, and rarely in the liver as primary sites. We report a case of Ewing sarcoma arising primarily in the liver and, to our knowledge, this is the fourth reported case of Ewing sarcoma occurring in the liver.

Case presentation

A 27-year-old Japanese woman was admitted with sudden onset right upper abdominal pain. Clinical examination revealed a multilocular cystic mass consisting of thickened, irregular septa and nodal walls in the right hepatic lobe. Ultrasound-guided aspiration biopsy of the liver mass showed clusters of small atypical round cells and the clinical preoperative diagnosis was mucinous cystadenoma of the liver. The patient underwent an extended right hepatectomy and histopathological findings revealed sheet-like proliferation of small- to medium-sized round cells. Tumor cells were positive for periodic acid-Schiff reaction and immunoreactive for glycoprotein C99 and gene NKX2.2, as well as the neuroendocrine markers, CD56 and synaptophysin. EWS-FLI-1 fusion transcript type 1 was detected by reverse transcriptase polymerase chain reaction. Pathological and molecular analysis confirmed the diagnosis of Ewing sarcoma arising primarily in the liver and the patient received adjuvant systemic chemotherapy with vincristine, doxorubicin, and cyclophosphamide, alternating with ifosfamide and etoposide. We found no evidence of recurrence 15 months after completing chemotherapy.

Conclusion

We present an extremely rare case of Ewing sarcoma arising primarily in the liver. To our knowledge, this is the fourth reported case of Ewing sarcoma occurring in the liver, and the first case with a multilocular cystic liver mass. Imaging examinations of the other three reported cases showed solid tumors and a diffuse enlarged liver without mass lesion. Clinicians should consider the possibility of Ewing sarcoma in young patients with a multilocular cystic mass with thick and/or irregular cyst walls in the liver.

3D tissue-engineered model of Ewing's sarcoma

Despite longstanding reliance upon monolayer culture for studying cancer cells, and numerous advantages from both a practical and experimental standpoint, a growing body of evidence suggests that more complex three-dimensional (3D) models are necessary to properly mimic many of the critical hallmarks associated with the oncogenesis, maintenance and spread of Ewing's sarcoma (ES), the second most common pediatric bone tumor. And as clinicians increasingly turn to biologically-targeted therapies that exert their effects not only on the tumor cells themselves, but also on the surrounding extracellular matrix, it is especially important that preclinical models evolve in parallel to reliably measure antineoplastic effects and possible mechanisms of de novo and acquired drug resistance. Herein, we highlight a number of innovative methods used to fabricate biomimetic ES tumors, encompassing both the surrounding cellular milieu and the extracellular matrix (ECM), and suggest potential applications to advance our understanding of ES biology, preclinical drug testing, and personalized medicine.

Rapidly progressive primitive neuroectodermal tumor of the prostate: A case report and review of the literature

The present study reports a rare case of primitive neuroectodermal tumor (PNET) of the prostate. A 23-year-old male presented to Oita Medical Center (Oita, Japan) with the complaint of dysuria and anal pain. A large mass in the prostate and a number of swollen lymph nodes in the pelvic region were identified by a computed tomography scan and magnetic resonance imaging. The patient was, thus, admitted to Oita University Hospital (Yufu, Japan), where a biopsy of the prostate gland was performed. Histological analysis revealed small round cells that were positive for MIC-2 expression and fluorescent in situ hybridization analysis detected a translocation involving Ewing sarcoma breakpoint region 1 at chromosome 22q12. Thus, a diagnosis of PNET of the prostate was established. Systemic chemotherapy was the selected treatment, however, a poor response was obtained. The patient succumbed approximately four months after the initial onset of symptoms. PNET of the prostate has been reported in eight cases worldwide; in comparison, the present case exhibited the most unsatisfactory outcome.

Ewing sarcoma/peripheral primitive neuroectodermal tumor in the adrenal gland of an adolescent: a case report and review of the literature

Ewing sarcoma/peripheral primitive neuroectodermal tumors (ES/pPNETs) typically occur in the long or flat bones, the chest wall, extraskeletal soft tissue, or less frequently, in solid organs. They can arise from anywhere in the body; however, ES/pPNETs arising from the adrenal gland are very rare, especially in children and adolescents. Herein, the authors report a case of an ES/pPNET in the adrenal gland of a 17-year-old girl, who was successfully treated with a multimodal treatment, with a brief review of the pertinent literature.

Renal primitive neuroectodermal tumour: Case series and brief review

Renal primitive neuroectodermal tumor is a rare malignancy. These tumours rarely present with caval involvement. We report 2 cases of primitive neuroectodermal tumours (PNETs) with inferior vena cava involvement. The initial presentation and outcomes differed significantly. The diagnosis was confirmed using histologic and pathologic analysis. We present a brief literature review and an outline of typical clinical and pathologic features of renal PNETs.

Primitive neuroectodermal tumor originating in the vulva: A case report

Primitive neuroectodermal tumors (PNETs) exhibit chromosomal translocations in common with those of Ewing’s sarcoma. They usually originate in bone or soft tissue but rarely arise in the vulva. The current case report presents a case of PNET originating in the vulva in a 60-year-old female, who previously underwent enucleation of a vulvar tumor in another hospital. The pathologist suspected a histopathological diagnosis of PNET, and simple vulvectomy and resection of the inguinal lymph nodes were performed. An ~3 cm mass recurred in the right side of the vulva four years following the initial surgery and the tumor was excised. The tumor comprised small, round-to-oval nuclei and stained positively for MIC-2, synaptophysin, neuron-specific enolase and neurofilament antibodies. To date, the patient remains alive and with no evidence of disease four years following multidisciplinary treatment, despite PNETs usually exhibiting a poor prognosis. This is due to the small tumor size and the absence of distant metastasis.

Primitive neuroectodermal tumor of the uterine cervix diagnosed during pregnancy: a rare case with review of literature

Primitive neuroectodermal tumors of the cervix are very rare. A 28-year-old pregnant woman presented with a cervical mass. The tumor was staged as IB2. The biopsy from tumor was suggestive of malignant small round cell tumor. She then underwent termination of pregnancy followed by radical hysterectomy. Based on morphologic and immunohistochemical profile, a diagnosis of peripheral primitive neuroectodermal tumor of the cervix was made. The patient received adjuvant chemotherapy and radiotherapy. The patient is alive and disease-free 33 months post-surgery. The present case highlights the importance of keeping primitive neuroectodermal tumors in the differential diagnosis of small cell neoplasms of the uterine cervix. Pregnancy should not be a barrier to early detection and treatment of this potentially aggressive tumor. The optimal treatment methods have not yet been established because of the rarity of the tumor.

Ewing's sarcoma arising from the adrenal gland in a young male: a case report

BACKGROUND

Ewing's sarcoma uncommonly arises from extraosseous soft tissue or parenchymal organs. Primary adrenal Ewing's Sarcoma, although very rare, is extremely aggressive and commonly fatal.

CASE PRESENTATION

A 17 year old Pakistani male was referred to the outpatient oncology clinic at our center with a three month history of concomitant pain, swelling and dragging sensation in the right hypochondrium. Abdominal examination revealed a large, firm mass in the right hypochondrium extending into the right lumbar region and epigastrium. His genital exam was unremarkable and there were no stigmata of hepatic or adrenal disease.Computed tomography scans revealed a large peripherally enhancing mass in the hepatorenal area, biopsy of which showed a neoplastic lesion composed of small round blue cells which exhibited abundance of glycogen and stained diffusely positive for CD99 (MIC2 antigen). Fluorescence in situ hybridization demonstrated gene rearrangement at chromosome 22q12 which confirmed the diagnosis of Ewing's sarcoma. Staging scans revealed pulmonary metastasis and hence he was commenced on systemic chemotherapy.

CONCLUSION

This case report highlights the importance of keeping Ewing's sarcoma in mind when a young patient presents with a large non-functional adrenal mass.

Usefulness of a monoclonal ERG/FLI1 antibody for immunohistochemical discrimination of Ewing family tumors

Ewing family tumors (EFTs) and prostate carcinomas are characterized by rearrangement of ETS genes, most commonly FLI1 (EFTs) and ERG (prostate carcinomas). Previously, we characterized an antibody against ERG (EPR3864) for detecting ERG-rearranged prostate carcinoma. Because EPR3864 also cross-reacts with FLI1, we evaluated the usefulness of EPR3864 for discriminating EFTs from other small round blue cell tumors (SRBCTs) with immunohistochemistry. Of 57 evaluable EFTs, 47 (82%) demonstrated at least moderate, diffuse, nuclear ERG/FLI1 staining (including 89% and 100% of cases with confirmed EWSR1:FLI1 and EWSR1:ERG fusions, respectively), of which 1, 3, and 43 showed negative, cytoplasmic, or membranous CD99 staining, respectively. Among other SRBCTs (61 cases, 7 types), at least moderate, diffuse, nuclear EPR3864 staining was seen in all precursor B-lymphoblastic lymphomas/leukemias and subsets of Burkitt lymphomas (10%) and synovial sarcomas (45%). In summary, EPR3864 may be useful in detecting EWSR1:FLI1 and EWSR1:ERG rearranged EFTs in addition to prostate carcinomas.

Ewing's sarcoma family of tumors in Finland during 1990-2009: a population-based study

BACKGROUND

Ewing's sarcoma family of tumors (ESFTs) are rare bone and soft tissue tumors characterized by specific genetic alterations. Our aim was to carry out a nationwide analysis of ESFT, to survey the treatments used and to report the five-year disease specific and event-free survival rates (EFS and DSS).

MATERIAL AND METHODS

The study data was gathered from the Finnish National Cancer Registry and all five University Hospitals and consisted of 76 bone and soft tissue ESFT patients diagnosed during 1990-2009. Their medical records were reviewed and data on their disease, treatments, complications and outcome were analyzed.

RESULTS

The five-year EFS and DSS of patients with localized disease at diagnosis (n = 57) were 70% and 60%, respectively. Factors contributing to DSS and EFS were the axial vs. peripheral site of primary tumor and adequate surgical resection of the primary tumor. DSS was also affected by patient's age at diagnosis and the treatment employed. The five-year DSS of patients with metastatic disease at diagnosis (n = 19) was 33% and both preoperative and high dose chemotherapy were associated with improved survival.

CONCLUSION

Population-based studies including both bone and soft tissue ESFTs are few. In this nationwide, population-based study on Finnish bone and soft tissue ESFT patients, we find their treatment successful and results comparable to those previously published. Absence of metastases, young age at diagnosis and a peripheral primary tumor site were associated with a better prognosis. It seems that surgical resection of the primary tumor should be performed whenever adequate resection margins can be achieved. The role of high dose chemotherapy merits further studies in this setting.

Dissecting the PI3K Signaling Axis in Pediatric Solid Tumors: Novel Targets for Clinical Integration

Children with solid tumors represent a unique population. Recent improvements in pediatric solid tumor survival rates have been confined to low- and moderate-risk cancers, whereas minimal to no notable improvement in survival have been observed in high-risk and advanced-stage childhood tumors. Treatments for patients with advanced disease are rarely curative, and responses to therapy are often followed by relapse, which highlights the large unmet need for novel therapies. Recent advances in cancer treatment have focused on personalized therapy, whereby patients are treated with agents that best target the molecular drivers of their disease. Thus, a better understanding of the pathways that drive cancer or drug resistance is of critical importance. One such example is the phosphatidylinositol 3-kinase (PI3K)/Akt/mammalian target of rapamycin (mTOR) pathway, which is activated in many solid cancer patients and represents a target for therapy. PI3K/Akt/mTOR pathway activation has also been observed in tumors resistant to agents targeting upstream receptor tyrosine kinases (RTKs). Agents that target this pathway have the potential to shut down survival pathways, and are being explored both in the setting of pathway-activating mutations and for their ability to restore sensitivity to upstream signaling targeted agents. Here, we examine the role of the PI3K/Akt/mTOR pathway in pediatric solid tumors, review the novel agents being explored to target this pathway, and explore the potential role of the inhibition of this pathway in the clinical development of these agents in children.

Unusual presentation of Ewing sarcoma in the adrenal gland: a secondary malignancy from a survivor of Burkitt lymphoma

The occurrence of Ewing sarcoma as a secondary malignancy is an extremely rare event in long-term cancer survivors. In addition, the occurrence of Ewing sarcoma in the adrenal gland is highly unusual. In this case report, we treated a 20-year-old male patient with cyclophosphamide, doxorubicin, vincristine, dexamethasone, and methotrexate and cytarabine chemotherapy following a diagnosis of Stage IV Burkitt lymphoma. Following complete remission, he had been maintained for 2 years without evidence of disease. However, a regular follow-up computed tomography scan found a left adrenal gland mass and a biopsy revealed positive membrane-localized mic-2 expression (CD99) and the presence of the translocation of the EWSR1 gene. To our knowledge, this is the first case report of Ewing sarcoma occurring in the adrenal gland of a patient who was treated with cyclophosphamide, doxorubicin, vincristine, dexamethasone/methotrexate and cytarabine chemotherapy for Burkitt lymphoma.

Molecular diagnostics complementing morphology in superficial mesenchymal tumors

Molecular techniques are increasingly important in the practice of surgical pathology. In soft tissue tumors, there are a number of tumors with recurring cytogenetic abnormalities. Knowledge of these abnormalities has furthered our understanding of these tumors and has also allowed development of molecular techniques to aid in the diagnosis. This review will focus on mesenchymal tumors with specific cytogenetic abnormalities that may present as a superficial tumor of the dermis or subcutis.

Prediction and identification of B cell epitopes derived from EWS/FLI-l fusion protein of Ewing's sarcoma

To predict B cell epitope of Ewing's sarcoma EWS/FLI-l fusion protein and to analyze its antigenicity and immunogenicity. Comprehensive algorithms were applied to predict the possible B cell epitopes of EWS/FLI-l fusion protein. High-performance liquid chromatography (HPLC) and mass spectrometry (MS) analysis were performed to identify the synthesized epitope peptides, ELISA assays and Western blot to detect the antigenicity, and the immunogenicity of epitope peptides. Three B cell epitopes were screened out, and HPLC and MS analysis confirmed all three synthesized epitope peptides were demandable. ELISA assays verified all three epitope peptides could prime intense antigen-antibody reaction and induce ideal antibody titers after immunization to the New Zealand white rabbit. However, Western blot confirmed that antiserum of one of these epitope peptides could not recognize EWS/FLI-1 protein. Two B cell epitopes, PQDGNKPTETSQPQ and DPDEVARRWGQRKS, derived from EWS/FLI-l protein, are identified to have potential antigenicity and immunogenicity.

Adult primary pulmonary primitive neuroectodermal tumor: molecular features and translational opportunities

Primitive neuroectodermal tumors (PNET) arising directly from the lung are very rare but particularly aggressive neoplasms. We report a case of a 31-y-old man with primary pulmonary neuroectodermal tumor. We review the clinical as well as pathological features. As typical for these tumors, the diagnosis was initially delayed in our patient and prognosis was poor despite aggressive surgical resection, postoperative chemotherapy and local irradiation. Recent biological insights have revealed unique chromosomal translocations crucial to the pathogenesis of these tumors, most notably the EWS-FLI-1 translocation. We provide an overview of the molecular features of the Ewing Sarcoma Family of Tumors (ESFT) including PNET and their potential implications for therapeutic targeting.

[Primitive neuroectodermal tumour of soft tissue of the index finger in an adult. A case report]

The primitive neuroectodermal tumours (PNET) of soft tissues belong to the Ewing's tumors family and affects particularly the child. The localization of the disease at the extremities is very rare within the adult population and raises the problem of differential diagnosis with others tumors of the soft tissues. We report the case of a 48-year-old patient with a localized tumor, at the level of the second right finger, of six months evolution. The biopsy showed the infiltrating nature of the tumour; and the diagnosis of (PNET) was confirmed after the histological and immunohistochemical study. The extension assessment was negative and the patient had an amputation of the second and third rays of the right hand. Four years afterwards, the patient showed no recurrence or metastases.

Renal primitive neuroectodermal tumors

Primitive neuroectodermal tumors exist as a part of the Ewing sarcoma/primitive neuroectodermal tumor family. These tumors most commonly arise in the chest wall and paraspinal regions; cases with a renal origin are rare entities, but have become increasingly reported in recent years. Although such cases occur across a wide age distribution, the average age for a patient with a renal primitive neuroectodermal tumor is the mid- to late 20s, with both males and females susceptible. Histologically, these tumors are characterized by pseudorosettes. Immunohistochemically, CD99 is an important diagnostic marker. Clinically, these are aggressive tumors, with an average 5-year disease-free survival rate of only 45% to 55%. Given that renal primitive neuroectodermal tumor bears many similarities to other renal tumors, it is important to review the histologic features, immunostaining profile, and genetic abnormalities that can be used for its correct diagnosis.

Congenital Askin tumor with favorable outcome: case report and review of the literature

Several disorders may present as cystic complex lesions of the fetal thorax, both with benign and malignant behavior. As a consequence, their detection may pose diagnostic, therapeutic, and parental counseling dilemmas. We describe a neonate with a congenital Askin tumor, diagnosed at the 37th week of gestation and treated after birth. Counseling and treatment challenges are discussed.

Expression of vascular endothelial growth factor in Ewing's sarcoma

PURPOSE

Vascular endothelial growth factor (VEGF) is the most potent stimulator of angiogenesis. The aim of this study was to evaluate the role of serum VEGF as a diagnostic, predictive and prognostic marker in Ewing's sarcoma.

METHODS

Patients with histopathologically proven diagnosis of Ewing's sarcoma without prior chemotherapy or radiotherapy were invited to take part in the study. Pre-chemotherapy, post-chemotherapy and post-surgery blood samples were collected for analysis of serum VEGF levels. Blood samples from ten sex- and age-matched healthy volunteers were collected for estimation of VEGF levels to act as control. Human VEGF Elisa kit (Bender Medsystem, Austria) was used to assess the serum VEGF levels.

RESULTS

A total of nine cases of Ewing's sarcoma were included in the study. Mean age in the group was 12.44 years (range, seven to 18 years). Mean and median serums VEGF level in the study population were 4,547.78 pg/ml and 3,780.00 pg/ml, respectively. Ten age- and sex-matched healthy volunteers were selected as controls. No significant correlation was obtained between serum VEGF, age, sex and tumour size. Mean serum VEGF was significantly raised in the study group as compared to controls (p = 0.001). We observed a significant decline in serum VEGF level following neoadjuvant chemotherapy (p = 0.008). No correlation could be established between serum VEGF level pulmonary metastasis and overall survival.

CONCLUSION

Serum VEGF might have a role as a diagnostic and predictive marker in patients with Ewing's sarcoma.

Targeted therapy in bone and soft tissue sarcoma in children and adolescents

Pediatric soft-tissue and bone sarcomas are a heterogeneous group of tumors of mesenchymal origin which affect approximately 1,500 children in the United States each year. Using multimodal therapy (surgery, radiation, and chemotherapy),the overall 5-year survival rate for children with soft-tissue and bone sarcomas is approximately 60%–70%. However, the prognosis for children with metastatic or recurrent disease is poor; and, furthermore, the improvements in the overall cure rate have slowed. It is highly unlikely that further advances in the treatment of pediatric soft-tissue and bone sarcomas will come from traditional cytotoxic chemotherapy. Based on research advances in understanding the biology of pediatric soft-tissue and bone sarcomas, improved cure rates will likely be driven by new types of treatment which target the specific abnormalities within these tumors. These new targeted therapies may include small molecules, antibodies, or other immunotherapies. This review briefly describes the biology of the major types of pediatric sarcomas, discusses potential targets for new therapy, and highlights some recent and current clinical trials using targeted therapy.

Ewing's sarcoma and primitive neuroectodermal tumour (ES/PNET) presenting as a breast mass

Ewing's sarcoma/primitive neuroectodermal tumour (ES/PNET) is a rare tumour usually detected in young individuals and uncommonly found within the breast tissue. In this case report, we examined a 46-year-old patient, who developed a lump on her breast and was later diagnosed with ES/PNET. Clinical presentation, age at development and radiological findings were of interest and were discussed. Diagnosis of the tumour was confirmed using various immunohistochemical studies and the presence of a translocation, t(11;22). A literature review of this rare condition was also included.

Fas/Fas ligand regulation mediates cell death in human Ewing's sarcoma cells treated with melatonin

Background:

Despite recent advances in cancer therapy, the 5-year survival rate for Ewing's sarcoma is still very low, and new therapeutic approaches are necessary. It was found previously that melatonin induces cell death in the Ewing's sarcoma cell line, SK-N-MC, by activating the extrinsic apoptotic pathway.

Methods:

Melatonin actions were analysed by metabolic viability/survival cell assays, flow cytometry, quantitative PCR for mRNA expression, western blot for protein activation/expression and electrophoretic mobility shift assay for transcription factor activation.

Results:

Melatonin increases the expression of Fas and its ligand Fas L, this increase being responsible for cell death induced by the indolamine. Melatonin also produces a transient increase in intracellular oxidants and activation of the redox-regulated transcription factor Nuclear factor-kappaB. Inhibition of such activation prevents cell death and Fas/Fas L upregulation. Cytotoxic effect and Fas/Fas L regulation occur in all Ewing's cell lines studied, and do not occur in the other tumour cell lines studied where melatonin does not induce cell death.

Conclusion:

Our data offers new insights in the study of alternative therapeutic strategies in the treatment of Ewing's sarcoma. Further attention deserves to be given to the differences in the cellular biology of sensitive tumours that could explain the cytotoxic effect of melatonin and the increase in the level of free radicals caused by this molecule, in particular cancer types.

Metastatic Ewing's sarcoma/PNET of kidney in 40 year old patient

INTRODUCTION

Primary renal Ewing sarcoma/PNET is an uncommon and very aggressive tumor.

PRESENTATION OF CASE

: We report the case of a young woman who underwent nephrectomy for a renal mass from unknown etiology. Histologic analysis found small tumoral cells in rosette formation, and immunohistochemical staining was positive for CD99, and focally positive for vimentin and Protein S-100. A post operative abdominal computed tomography (CT) scan revealed a residual renal processus with hepatic wounds and abdominal metastatic nodes. After 6 cycles of chemotherapy including Vincristine, Doxorubicin, Cyclophosphamide, the response was considered as good.

DISCUSSION

Ewing's sarcoma/PNET of kidney is a member of the family of small round cell tumors and it should be differentiated from Wilms tumor, neuroblastoma, rhabdomyosarcoma and lymphoblastic lymphoma. The principle management of its treatment have been extrapolated from the treatment of osseous Ewing sarcoma of bone.

CONCLUSION

Despite aggressive treatment, primary renal Ewing sarcoma/PNET has a poor prognosis. It requires a multidisciplinary approach including oncologists, urologists and radiation oncologists.

Primitive neuroectodermal tumor of the liver: a case report

Primary liver sarcomas represent a rare group of neoplasias, with angiosarcoma being the most common histological type. Primitive neuroectodermal tumor (PNET) represents a high malignant neoplasia that usually affects the central nervous system and soft tissues. An 18-year-old male patient was admitted with clinical complains of pain in the right upper abdominal quadrant. The clinical evaluation revealed a solid mass in the right hepatic lobe. On the gross examination of the resected liver specimen, the right lobe of the liver was replaced by a yellow-red solid mass measuring 21 cm in its largest dimension. On the histopathology, a tumor composed of small round blue cells with little cytoplasm and round nuclei was identified. The lesion revealed positive immunoexpression for vimentin and CD99 and negative immunostaining for desmin, CD45, cytokeratin, and neuroblastoma protein, suggesting, then, the diagnosis of PNET. Although it is an unusual tumor, it should be considered in the differential diagnosis of liver masses, especially in young patients.

Small blue round cell tumor: an unusual case presentation in the foot

Small blue round cell tumors of childhood rarely present in the foot or ankle. The following is a case presentation of an 18-year-old male with a large soft-tissue mass of the foot with associated lung metastasis. A definitive diagnosis could not be fully made, even with immunohistochemical and genetic testing. Diagnosis favored poorly differentiated synovial sarcoma.

Peripheral primitive neuroectodermal tumour of the liver: a case report and review of the literature

Peripheral primitive neuroectodermal tumour (PNET) is a malignant mesenchymal tumour. Although PNETs can occur in numerous solid organs, it is an extremely rare tumour entity, specially involving the liver. We report a 19-year-old boy with Hepatitis B Virus (HBV) infection who was diagnosed with a primary PNET of the liver.

Intraspinal primitive neuroectodermal tumor in a man with neurofibromatosis type 1: Case report and review of the literature

BACKGROUND

The occurrence of primitive neuroectodermal tumors (PNET) in patients with neurofibromatosis type 1 (NF1) has only been reported in two other cases in English-Language literature. Owing to the rarity of intraspinal PNET and the extremely high gene mutation variability in NF1, there is currently no conclusive evidence to suggest that PNET is associated with NF1. Here, we report a case of intradural PNET in a patient with NF1.

CASE DESCRIPTION

A 27-year-old male underwent a C1-C3 laminectomy for resection of an intramedullary mass. Histopathology and immunohistopathology analysis was performed. Microscopic examination and immunohistochemical staining indicated the mass was a primitive neuroectodermal tumor. Within 1 month after tumor resection, the patient developed leptomeningeal carcinomatosis. The patient was not a candidate for radiation therapy but underwent palliative systemic chemotherapy. He subsequently developed neutropenia and died 3 months after tumor resection.

CONCLUSION

To our knowledge, this is the first reported intraspinal PNET associated with NF1. Genetic analysis of CNS PNETs suggests a possible correlation, but larger case series are needed to support this theory.

Primary Vaginal Ewing Sarcoma

Ewing sarcoma (ES) and primitive neuroectodermal tumor (PNET) are round-cell sarcomas with varying degrees of neuroectodermal differentiation; they are considered members of the same family of tumors based on their common genetic profile. ES/PNET are very infrequent in the female genital tract, the vagina being the rarest gynecological location, with 7 cases reported to date. The authors present a case of vaginal ES/PNET with typical morphological and immunohistochemical features. EWS gene rearrangement was demonstrated by fluorescent in situ hybridization analysis. Of the 7 previously reported cases, only 2 have molecular confirmation. The age at presentation for vaginal ES/PNET is slightly higher than that for these neoplasms in bone and soft tissues, with only 1 reported patient younger than 30 years. The outcome seems to be similar to that of other superficially sited ES/PNET and more favorable than for those observed in the more typical locations. However, the currently available data are limited, and therefore, a larger number of cases is necessary to draw any firm conclusions.

Primary Ewing's sarcoma/primitive neuroectodermal tumor of the vagina in a 54-year-old woman: a case report

BACKGROUND

Ewing's sarcoma (ES)/primitive neuroectodermal tumor (PNET) of the genital tract of women is uncommon. Presentation in vagina is exceedingly rare.

CASE

A 54-year-old Chinese woman presented with complaints of vaginal bleeding with fragmented bits occasionally. Physical examination revealed two nodules about 4 cm × 3 cm in the vagina. The immunohistochemical stains revealed a rare presentation of a primitive neuroectodermal tumor. The patient was treated with whole-pelvis external beam radiation, vaginal cylinder intracavitary brachytherapy, intracavitary afterloading radiotherapy and bilateral groin area radiotherapy. She died of clinical recurrence after 18 months of treatment.

CONCLUSION

This is the oldest but virgin case, treated with radiation completely, of primitive neuroectodermal tumor located in the vagina reported in the literature.

Uncommon presentation of rare disorder-duodenal ulcer secondary to invasive pancreatic primitive neuroectodermal tumor: case report and review of the literature

The authors report an unusual presentation of a rare tumor in childhood, a pancreatic primitive neuroectodermal tumor invading the duodenum leading to anemia. A review of intra-abdominal primitive neuroectodermal tumors is discussed.

Modeling sarcomagenesis using multipotent mesenchymal stem cells

Because of their unique properties, multipotent mesenchymal stem cells (MSCs) represent one of the most promising adult stem cells being used worldwide in a wide array of clinical applications. Overall, compelling evidence supports the long-term safety of ex vivo expanded human MSCs, which do not seem to transform spontaneously. However, experimental data reveal a link between MSCs and cancer, and MSCs have been reported to inhibit or promote tumor growth depending on yet undefined conditions. Interestingly, solid evidence based on transgenic mice and genetic intervention of MSCs has placed these cells as the most likely cell of origin for certain sarcomas. This research area is being increasingly explored to develop accurate MSC-based models of sarcomagenesis, which will be undoubtedly valuable in providing a better understanding about the etiology and pathogenesis of mesenchymal cancer, eventually leading to the development of more specific therapies directed against the sarcoma-initiating cell. Unfortunately, still little is known about the mechanisms underlying MSC transformation and further studies are required to develop bona fide sarcoma models based on human MSCs. Here, we comprehensively review the existing MSC-based models of sarcoma and discuss the most common mechanisms leading to tumoral transformation of MSCs and sarcomagenesis.

Extraosseous Ewing's sarcoma of the pancreas

The Ewing's family of tumors (EFT) comprises a molecularly defined group of "small round blue cell tumors", consisting of Ewing's sarcoma of bone (ESB), extraosseous Ewing's sarcoma (EES), peripheral primitive neuroectodermal tumor (pPNET), and Askin's tumor. Characteristic translocations that disrupt the EWSR1 gene located at 22q12 create novel fusion genes that are central to the pathogenesis. The EFT also shares certain clinical characteristics, such as a peak incidence during the teenage years, a tendency to spread rapidly, and responsiveness to the same chemotherapeutic regimens and radiation therapy. Nearly all patients have occult disseminated disease at diagnosis; hence, chemotherapy is routinely used. Improvements in multimodality treatment have had a dramatic impact on outcomes. EES/pPNET has been reported in a variety of sites, including the pancreas, though this is extremely rare. We describe a case of pancreatic EES/pPNET in a 35-year-old woman and provide a brief review of the relevant literature.

Molecular approaches to sarcoma therapy

Soft tissue sarcomas comprise a heterogeneous group of aggressive tumors that have a relatively poor prognosis. Although conventional therapeutic regimens can effectively cytoreduce the overall tumor mass, they fail to consistently achieve a curative outcome. Alternative gene-based approaches that counteract the underlying neoplastic process by eliminating the clonal aberrations that potentiate malignant behavior have been proposed. As compared to the accumulation of gene alterations associated with epithelial carcinomas, sarcomas are frequently characterized by the unique presence of a single chromosomal translocation in each histological subtype. Similar to the Philadelphia chromosome associated with CML, these clonal abnormalities result in the fusion of two independent unrelated genes to generate a unique chimeric protein that displays aberrant activity believed to initiate cellular transformation. Secondary gene mutations may provide an additional growth advantage that further contributes to malignant progression. The recent clinical success of the tyrosine kinase inhibitor, STI571, suggests that therapeutic approaches specifically directed against essential survival factors in sarcoma cells may be effective. This review summarizes published approaches targeting a specific molecular mechanism associated with sarcomagenesis. The strategy and significance of published translational studies in six distinct areas are presented. These include: (1) the disruption of chimeric transcription factor activity; (2) inhibition of growth stimulatory post-translational modifications; (3) restoration of tumor suppressor function; (4) interference with angiogenesis; (5) induction of apoptotic pathways; and (6) introduction of toxic gene products. The potential for improving outcomes in sarcoma patients and the conceptual obstacles to be overcome are discussed.

Specific recognition and inhibition of Ewing tumour growth by antigen-specific allo-restricted cytotoxic T cells

Background:

The development of a successful immunotherapy is hampered by an ineffective T-cell repertoire against tumour antigens and the inability of the patient's immune system to overcome tolerance-inducing mechanisms. Here, we test the specific recognition and lytical potential of allo-restricted CD8⁺ T cells against Ewing tumour (ET) associated antigens Enhancer of Zeste, Drosophila Homolog 2 (EZH2), and Chondromodulin-I (CHM1) identified through previous microarray analysis.

Methods:

Following repetitive CHM1³¹⁹ (VIMPCSWWV) and EZH2⁶⁶⁶ (YMCSFLFNL) peptide-driven stimulations with HLA-A^*0201⁺ dendritic cells (DC), allo-restricted HLA-A^*0201⁻ CD8⁺ T cells were stained with HLA-A^*0201/peptide multimers, sorted and expanded by limiting dilution.

Results:

Expanded T cells specifically recognised peptide-pulsed target cells or antigen-transfected cells in the context of HLA-A^*0201 and killed HLA-A^*0201⁺ ET lines expressing the antigen while HLA-A^*0201^– ET lines were not affected. Furthermore, adoptively transferred T cells caused significant ET growth delay in Rag2^−/−γ_C^−/− mice. Within this context, we identified the CHM1³¹⁹ peptide as a new candidate target antigen for ET immunotherapy.

Conclusion:

These results clearly identify the ET-derived antigens, EZH2⁶⁶⁶ and CHM1³¹⁹, as suitable targets for protective allo-restricted human CD8⁺ T-cell responses against non-immunogenic ET and may benefit new therapeutic strategies in ET patients treated with allogeneic stem cell transplantation.