Peripheral primitive neuroectodermal tumor (peripheral neuroepithelioma) in children. A review of the St. Jude experience and controversies in diagnosis and management

Peripheral primitive neuroectodermal tumors: A retrospective analysis of 89 cases and literature review

Peripheral primitive neuroectodermal tumors (pPNETs) are rare, small cell carcinomas with a poor prognosis. The aim of the present study was to describe therapeutic approaches, outcomes and probable prognostic factors. The clinical features, treatments, and outcomes of 89 consecutive patients with pPNET treated at the Peking Union Medical College Hospital from 1999 to 2018 were retrospectively reviewed. A total of 43 males and 46 females were included in the study, with a median age of 25 years (range, 5-73 years). The predominantly affected regions were the abdomen and pelvis, followed by the thoracopulmonary region. The mean primary tumor size was 12.6 cm (range, 1-30 cm). A total of 16 patients (18%) initially presented with metastasis. A total of 46 patients received combined therapy, 35 received mono-therapy, and 8 underwent only biopsy with no further treatment. The period of observation ranged from 1-232 months. The median overall survival (OS) time was 15 months [95% confidence interval (CI), 9-21 months], with 3- and 5-year OS rates of 32 and 25%, respectively. Large tumor size [adjusted hazard ratio (aHR)=3.65; 95% CI, 2.07-6.42; P<0.001), metastasis at initial presentation (aHR=4.34, 95% CI, 2.23-8.42; P<0.001), and combined modality treatment (aHR=0.16, 95% CI, 0.06-0.39; P<0.001) were significantly associated with OS. The prognosis of pPNET is, overall, poor. Large tumor size and metastasis at initial presentation are associated with poorer outcomes. This highly malignant tumor requires an aggressive combination of radical resection, chemotherapy and radiotherapy, when indicated.

Ewing sarcoma/primitive neuro-ectodermal tumor of the urogenital system in children: a retrospective observational case series

INTRODUCTION

Pediatric Ewing sarcoma (ES)/primitive neuro-ectodermal tumor (PNET) occurring in the genitourinary system has been rarely reported. And the result of long-term follow-up is still a matter of debate.

OBJECTIVE

The aim of the study was to identify the characteristics, therapeutic strategies, and long-term outcomes of pediatric ES/PNET in the genitourinary system.

PATIENTS AND METHODS

All children with genitourinary system PNET from a single center were retrospectively reviewed. The American Joint Committee on Cancer (AJCC) staging system was used to evaluate tumor grade.

RESULTS

Four patients were included. Three were boys, and 1 was a girl. The locations of the lesions were the penis in 1 patient, ureter in 1 patient, and kidney in 2 patients. Two patients were of AJCC stage IVB, and the other 2 patients were of stage IIA. In the follow-up ranging from 2.5 to 8.0 years, 3 patients had survival, and 1 patient died. The patient with penis PNET survived during the 8 years of follow-up. One patient with renal PNET had tumor thromboses in the renal vein, inferior vena cava, and right atrium, which was the first definite report in children (case 3).

DISCUSSION

Primitive neuro-ectodermal tumor as a highly malignant subgroup of blue round cell tumor is extremely rare in the genitourinary system, especially in children. The current case series represents the first report of penis PNET in children with the longest (8 years) follow-up and first definite report of pediatric renal PNET with vena cava and atrium tumor thrombus. In contrast to the previous literature, the patient with ureteral PNET in this study was much younger, who was the youngest child to be reported in the literature thus far. Although the key prognostic factor of the outcomes is detectable metastases at diagnosis, the patient with penis PNET and bone and lung metastasis in this series still survived. It was hypothesized from the data of present cases that young age was a protective factor, which was consistent with the previous literature. Aggressive therapy is not trivial for patients with multiple recurrences who can also be a long-term survivor. The survival outcomes of these high-stage patients were favorable with combination treatment. As the patient with penis PNET in this series had bone metastasis at his 7.5 years after definite diagnosis, five years of follow-up was not enough. The follow-up period should be extended, even to a lifetime follow-up.

CONCLUSIONS

Children with PNET have a better prognosis than adults. Aggressive combination treatment should be performed to improve prognosis and the survival rate. It is better to monitor the changes of the disease by extending the follow-up period.

From Ataxia to Diagnosis of Askin Tumor - a Case Report

Peripheral primitive neuroectodermal tumors (pPNET) are a group of extremely rare, aggressive, malignant tumors that are most often found in the thorax (Askin tumor), abdomen, pelvis, extremities and less frequently in the head and neck. The most important prognostic factor is the stage of the tumor. Significant progress both in surgery and in neoadjuvant and adjuvant chemotherapy and radiotherapy, as well as the improvement in diagnosis by cytogenetic and immunohistochemical analysis, should improve the survival rate. We report a case of a 14-year-old girl, with ataxic gait, cardiopulmonary compensated, without respiratory symptoms, who was referred to our hospital for further examination and treatment of newly discovered tumor of the left hemithorax. After a detailed radiological and laboratory investigation, next step was an extensive thoraco-neurosurgical surgery. After histopathological, cytological and molecular analysis, a diagnosis of Askin tumor was made.

Comparison of Epidemiology, Clinical Features, and Outcomes of Patients with Reported Ewing Sarcoma and PNET over 40 Years Justifies Current WHO Classification and Treatment Approaches

Background

As of 2013, the WHO has classified peripheral primitive neuroectodermal tumors (PNETs) within the umbrella of Ewing sarcoma family of tumors (ESFTs) given their shared biology. Histologic features differ between PNET and Ewing sarcoma (ES), and potential clinical differences between PNET and ES have not been fully elucidated.

Methods

Through the National Cancer Institute's Surveillance, Epidemiology, and End Results (SEER) database, we identified 3,575 patients identified with histologic diagnosis of ES or PNET from 1973 to 2014. We used Fisher's exact tests to compare patient and tumor characteristics between groups. Kaplan-Meier methods were used to estimate overall survival.

Results

Patients with ES were more likely to be male, ≤18 years old at diagnosis, white, and hispanic compared to patients with PNET (p=0.016 for sex; p < 0.001 for all other variables). Patients with PNET were more likely to have soft tissue primary tumors (p < 0.001), and among those with bone tumors, a lower rate of axial or pelvic tumors (p < 0.001). Patients with PNET had significantly worse 5-year survival compared to ES patients, though the absolute difference was small (51.3% versus 55.5%; p < 0.001). Survival of patients with PNET diagnosed in the 1990s or later more closely approximated patients with ES, while patients with PNET diagnosed in the 1980's and earlier had inferior outcomes.

Conclusions

Despite shared underlying biology, patients with PNET and ES show differences in clinical presentation and overall survival, with the latter differences largely mitigated in more recent decades.

Peripheral Primitive Neuroectodermal Tumor (Ppnet) of Pelvic Origin: Report of a Case Arising from an Unusual Location

A peripheral primitive neuroectodermal tumor arising from the abdominopelvic cavity is reported in a 24-year-old young male without any previous remarkable pathology. He was admitted to our hospital with complaints of urinary symptoms (acute urinary retention) and mild intestinal occlusion that had been present for three months. Physical examination and CT scan revealed a pelvic mass occupying the entire pelvic cavity. The diagnostic workup included a CT-guided biopsy which defined the tumor as a sarcomatous type. Radical surgery was performed including tumor resection, pelvic exenteration (bladder and prostate gland) and urinary and fecal diversion. Adjuvant chemotherapy (VAIA) was delivered once the histology was confirmed. We reviewed the available literature focusing on the varied nomenclature of this tumor (peripheral neuroepithelioma, Askin's tumor, Ewing's extraosseous tumor, peripheral adult neuroblastoma, peripheral primitive extracranial neuroectodermal tumor (PPNET), the clinical features, the role of diagnostic imaging techniques, pathologic assessment and controversial therapeutic management. In addition, the prognosis and survival of this rare condition were analyzed.

Ewing sarcoma of the adrenal gland: a case report and review of the literature

Background

Ewing sarcoma/primitive neuroectodermal tumor is a family of highly malignant proliferation of neuroectodermal origin, most often skeletal, adrenal localization is extremely rare. Only few cases have been reported in the literature. Classical management includes radical surgery with adjuvant chemotherapy or radiotherapy or both. This case report is the only one where recurrence was surgically removed, and it confirms the importance of adjuvant treatment, and the efficacy of neoadjuvant chemotherapy.

Case presentation

We report the case of a 23-year-old Moroccan woman presenting with flank pain. An abdominal computed tomography scan showed a large and enhancing left suprarenal mass. After radical nephrectomy, histologic examination revealed a small round cell proliferation. The diagnosis of Ewing sarcoma was confirmed by molecular analysis; time to final diagnosis was 5 months due to financial and coordination issues. Computed tomography (on an asymptomatic patient) revealed a locoregional recurrence, our patient received 12 cycles of the vincristine, doxorubicin and cyclophosphamide/ifosfamide and etoposide protocol used in an alternating schedule, with partial radiologic response (62%) and pathologic complete response, then underwent adjuvant radiotherapy of 45 Gy. The young women is still in remission after 36 months of follow-up.

Conclusions

Our patient had an early recurrence due to absence of adjuvant treatment, but did respond well to neoadjuvant chemotherapy with a pathologic complete response. Management of adrenal Ewing sarcoma could be extrapolated from skeletal one with good outcomes even in locoregional recurrence.

Adrenal mass of unusual etiology: Ewing sarcoma in a young man

Ewing sarcoma and peripheral primitive neuroectodermal tumor belong to the Ewing sarcoma (ES) family of tumors originating from a primitive neural tube. We report a 31-year-old man who was admitted to the urology clinic with complaints of fever, nausea, and dysuria. A right-sided adrenal mass was detected during ultrasonography. The lesion was then evaluated with magnetic resonance imaging, which showed areas of necrosis amid heterogeneous solid areas. Whole body scan with 2-deoxy-2-[fluorine-18]fluoro-D-glucose integrated with computed tomography and bone scan studies showed pulmonary and osseous metastatic foci. The mass and right kidney were removed by an open approach. An immunohistochemical and molecular workup enabled the diagnosis of ES. The patient also underwent radiotherapy and chemotherapy. The patient remained in fairly good health during the 18-month follow-up period, but showed progression of all metastatic foci and died 26 months after treatment. In conclusion, adrenal ES should be included in the differential diagnosis of nonfunctional adrenal lesions despite its rare occurrence.

Paediatric Peripheral Primitive Neuroectodermal Tumour - A Clinico-Pathological Study from Southern India

Introduction

Primitive Neuroectodermal Tumour (PNET)/Ewing Sarcomas (ES) are aggressive childhood malignancies with neuroectodermal differentiation.

Aim

To study the clinical presentation, morphology, Immun-ohistochemistry (IHC), management and outcome of all the cases of paediatric pPNET/ES reported in our tertiary care centre over a period of six years.

Materials and Methods

This was a retrospective study conducted at Sri Ramachandra Medical College and Research Institute, Chennai, India. All biopsy proven cases of peripheral PNET/ES, in patients less than 18 years of age for a period of six years were included in this study. The corresponding clinical details regarding initial presentation, treatment and follow up were retrieved from the case files and analysed. Survival rate was calculated and Kaplan-Meier survival curve was plotted.

Results

We describe eleven cases of paediatric peripheral PNET/ES. The mean age at presentation was 94.08 (±58.27) months with a male/female ratio of 1.2:1. About 27.3% cases, all male with a mean age of 140 months at presentation, had distant metastasis during initial diagnosis. Biopsy showed small round blue cell morphology on light microscopy. IHC revealed strong membranous staining for CD99 in all cases. All children were treated with neo-adjuvant chemotherapy and then surgery, followed by radiotherapy if indicated. The cases were followed up for a mean duration of 20.82 months (ranging from one to 66 months). Nine children are doing well on follow up (81.8% survival rate). Two cases with metastasis at initial presentation died. Patients with metastatic disease exhibited a mean duration of survival of 9.66 (±7.24) months and those with localized disease exhibited a mean duration of survival of 25 (±22.88) months.

Conclusion

Metastasis at diagnosis is the single most important factor affecting prognosis. This was reflected in the present study where cases with metastasis exhibited a short mean duration of survival when compared to localized disease. It is likely that many cases of PNET/ES were not accurately identified in the past as IHC plays a vital role in the diagnosis of these small round blue cell tumours. IHC in adjunct with molecular studies has improved diagnostic accuracy. Multidisciplinary management and good supportive care when the lesion is localized has lead to improved survival.

Rare adrenal gland incidentaloma: an unusual Ewing's sarcoma family of tumor presentation and literature review

Background

Members of the Ewing’s sarcoma family of tumor (ESFT) are malignant neoplasms and rarely observed in the adrenal gland.

Case presentation

We report an extremely exceptional case of ESFT rising from the adrenal gland in a 57-year-old Chinese man. The patient was hospitalized with abdominal swelling for 2 months. Computed tomography (CT) scan revealed a nearly-circular mass measuring about 8.1 × 10.6 cm in the right adrenal region. The patient underwent right adrenal resection. Histopathologic examination found the tumor was composed of small round blue cells forming typical Homer-Wright rosettes in focal area. The immunohistochemical analysis confirmed the case to be ESFT, which was positive for membranous CD99 and nuclear FLI-1. The patient was scheduled for four courses of large doses of chemotherapy and died for cancer metastasis one year later after surgery.

Conclusions

Histopathological evidence of Homer-Wright rosettes and immunohistochemical markers positivity, such as CD99 and FLI-1, are valuable factors for ESFT diagnosis, although cytogenetic analysis is considered as the gold standard. Complete surgery is the treatment of choice for ESFT and adjuvant radiotherapy and combination chemotherapy can significantly improve the survival rate of postoperative patients.

Peripheral Neuroectodermal Tumor-Ewing's Sarcoma of the Thumb With Local Recurrences and Pleural Metastases After 17 Years

We report a case of an 8-year-old boy who initially presented with a painful subungual mass that was diagnosed as a "glomus tumor" largely based on the clinical presenta tion. Local excision was performed, and the patient remained tumor free for 17 years, after which he experienced three local recurrences and massive pleural metastases within the next 2 years. The tumor was poorly differentiated with small round cells and increased mitotic activity on light microscopy. The precise nature of the tumor was difficult to characterize and was unraveled primarily by immunoperoxidase studies, particularly the diffuse strong positivity of HBA-71 (MIC 2) antibody, also called pe ripheral neuroectodermal tumor-Ewing's sarcoma antigen, which is reported to be fairly specific for these tumors, and the expression of neural markers Leu-7 (HNK-1 ) and neuron-specific enolase. In addition, ultrastructural examination revealed imma ture cell junctions, cell processes, and abundant pools of intracytoplasmic glycogen. Metastatic pleural tumor recurred very rapidly after excision, but showed a dramatic, although short-lasting, response to chemotherapy with cisplatin and etoposide. The thumb is an uncommon location for peripheral neuroectodermal tumor-Ewing's sar coma, and a 17-year, disease-free interval is most unusual for a malignant tumor of this nature. We discuss this case with respect to its unique clinical behavior and in the context of the differential diagnosis of small, round cell neoplasms. Int J Surg Pathol 2(2):147-156, 1994

Primary Ewing sarcoma/primitive neuroectodermal tumor in the adrenal gland

Primary Ewing sarcoma or primitive neuroectodermal tumor (PNET) of the adrenal gland is extremely rare. We report a case of Ewing sarcoma or PNET of the adrenal in a 48-year-old Chinese woman. The patient was hospitalized with left upper quadrant abdominal pain and swelling that had been present for 1 year. Computed tomography (CT) images revealed a circumscribed mass in the left adrenal region measuring 12 cm in its greatest dimension, and the mass was surgically resected. Macroscopically, the mass (13 × 10 × 8 cm³ ) in the left adrenal gland was encapsulated, soft, appearing grayish white and yellow, and with foci of cystic degeneration, necrosis, and hemorrhage on cross-sectional. Non-tumorous adrenal tissue was compressed, but identifiable at the periphery of the specimen. Histologically, compact short spindle and oval tumor cells were arranged in sheets. Tumor cells tested positive for vimentin, CD99, Bcl-2, NKX2.2, EMA, and CD117, and weakly positive for FLI-1 on immunohistochemical analysis and showed rearrangement of the EWSR1 on fluorescence in situ hybridization analysis. Post-adrenalectomy, after being recurrence free for 4.5 years, the patient relapsed and a localized recurrence was detected on a follow-up CT scan.

Carboplatin in the treatment of Ewing sarcoma: Results of the first Brazilian collaborative study group for Ewing sarcoma family tumors-EWING1

BACKGROUND

Large cooperative group studies have shown the efficacy of risk-adapted treatment for Ewing sarcoma. However, validation and local adaptation by National cooperative groups is needed. A multicenter protocol to determine the efficacy and safety of a risk-adapted intensive regimen was developed by the Brazilian cooperative group.

PROCEDURE

Patients <30 years old with Ewing sarcoma were eligible. Induction chemotherapy consisted of two cycles of ICE (ifosfamide, carboplatin, and etoposide) followed by two cycles of VDC (vincristine, doxorubicin, and cyclophosphamide), followed by local control. Patients with low risk (LR) disease (localized resectable with normal LDH) received 10 additional alternating courses of IE with VDC. For patients with high-risk (HR) disease (unresectable, pelvic, metastatic, or high LDH), two additional cycles of ICE were given.

RESULTS

One-hundred seventy five patients (39% metastatic) were enrolled. Fifty-two patients (29.7%) were LR and 123 (70.3%) were HR. Overall response rate at end of induction was 27.4%. Five-year event-free survival (EFS) and overall survival (OS) estimates were 51.4% and 54.4%, respectively. Patients with localized disease had better outcomes than patients with metastases (5-year EFS 67.9% vs. 25.5%, and 5-year OS 70.3% vs. 29.1%, respectively). On multivariate analysis, the presence of metastatic disease was the only prognostic factor (P < 0.01).

CONCLUSION

The VDC/ICE protocol was feasible, and considering the high tumor burden in our population, resulted in comparable results to those reported by cooperative groups in high-income countries. Further adaptation to maximize efficacy and minimize toxicity will be required.

Peripheral primitive neuroectodermal tumor in masseter muscle

Primitive neuroectodermal tumor is a member of malignant small round cell tumors. These tumors especially originate from the central and autonomous nervous system. However, these tumors may be originated from peripheral tissues and are called peripheral primitive neuroectodermal tumor. A 14-year-old girl attended to the Ear Nose Throat Clinic with the complaint of progressive painless swelling mass for 2 months on the right side of the face. Neck magnetic resonance imaging showed 3.5 × 2.5 × 2-cm isointense mass on T1 and hyperintense on T2 sequences. There was no pathological lymphadenopathy on computed tomographic scan. As a result of mandibular cortical invasion seen on computed tomographic scan, radical surgical excision was decided as surgical treatment. Total parotidectomy with preserving facial nerve and partial mandibulectomy with a 2-cm margin of safety were done, and reconstruction plaque applied to the mandible. Two lymph nodes were seen at the submandibular region. For this reason, prophylactic supraomohyoid neck dissection had also been performed. Pathological assessment proved the diagnosis of PNET, and chemoradiotherapy was planned for the patient.To our knowledge, this is the second reported case in literature. In this present case, peripheral neuroectodermal tumor in the masseter muscle and its diagnosis and treatment process were reported with literature review.

Primitive neuroectodermal tumor of the maxillary sinus in an elderly male: A case report and literature review

Primitive neuroectodermal tumor (PNET), which belongs to the Ewing's sarcoma (ES) family of tumors, is mainly seen in children and young adults. PNETs are extremely rare in the maxilla. Here, we report a case of PNET of the left maxillary sinus in an elderly male. Magnetic resonance imaging (MRI) revealed a slightly enhanced solid mass occupying the left maxillary sinus and infiltrating into the retroantral space. A partial maxillectomy was performed. Despite postoperative chemotherapy, follow-up computed tomography (CT) and MRI revealed a nodal metastasis in the submandibular space. Neck dissection was performed. However, the patient died 10 months after the second surgery because of distant metastasis to the liver. MRI and CT were particularly useful in detecting the extent of the tumor, recurrence, and metastasis. Further, a literature review of the previously reported PNET cases of the maxilla was carried out. In this paper, we also discuss the current approach for the diagnosis and management of these tumors.

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.

Askin tumor mimicking a hydatid cyst of the lung in children: case report

Askin tumor is a malignant small round cell tumor that originates from the thoracopulmonary region, usually observed in young subjects. We report a case of askin tumor in a 11 year-old men, who had in his past history a surgery for hydatid cyst of the liver, actually hospitalised for right pulmonary upper lobe mass of the lung. After resection of the mass, the pathological exam confirmed the diagnosis of primitive neuroectodermal tumor (PNET). An adjuvant treatment (radiotherapy and chemotherapy) was done; the patient died 11 months after surgery. Askin tumor is an exclusion diagnosis not always readily made.

Preclinical evaluation of engineered oncolytic herpes simplex virus for the treatment of pediatric solid tumors

Recently, investigators showed that mice with syngeneic murine gliomas that were treated with a neuroattenuated oncolytic herpes simplex virus-1 (oHSV), M002, had a significant increase in survival. M002 has deletions in both copies of the γ134.5 gene, enabling replication in tumor cells but precluding infection of normal cells. Previous studies have shown antitumor effects of other oHSV against a number of adult tumors including hepatocellular carcinoma and renal cell carcinoma. The purpose of the current study was to investigate the oncolytic potential of M002 against difficult to treat pediatric liver and kidney tumors. We showed that the oHSV, M002, infected, replicated, and decreased cell survival in hepatoblastoma, malignant rhabdoid kidney tumor, and renal sarcoma cell lines. In addition, we showed that in murine xenografts, treatment with M002 significantly increased survival and decreased tumor growth. Finally, these studies showed that the primary entry protein for oHSV, CD111 (nectin-1) was present in human hepatoblastoma and malignant rhabdoid kidney tumor specimens. We concluded that M002 effectively targeted these rare aggressive tumor types and that M002 may have potential for use in children with unresponsive or relapsed pediatric solid tumors.

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.

Askin's tumor: a case report and literature review

Askin's tumor is a primitive neuroectodermal tumor developing from the soft tissues of the chest wall. Its diagnosis approach is complex and requires a multidisciplinary team. Given the rarity of this entity, no regimen has been validated in the literature. We report two cases of Askin's tumor with a major response to polychemotherapy and surgical resection in one case. These cases show that treatment of Askin's tumor should be multimodal, requiring discussion in multidisciplinary tumor working groups.

Ewing sarcoma/peripheral primitive neuroectodermal tumor and related tumors

Ewing sarcoma/peripheral primitive neuroectodermal tumor (EWS/pPNET) and other tumors with EWS gene rearrangements encompass a malignant and intermediate neoplasm with a broad anatomic distribution and a wide age range but a predilection for soft tissue in children, adolescents, and young adults. The overlapping histologic, immunohistochemical and cytogenetic and molecular genetic features create diagnostic challenges despite significant clinical and prognostic differences. Ewing sarcoma is the 3rd most common sarcoma in children and adolescents, and desmoplastic small round cell tumor is a rare neoplasm that occurs more often in older children, adolescents, and young adults. Pathologic examination is complemented by immunohistochemistry, cytogenetics, and molecular genetics. This article reviews the clinicopathologic features of EWS/pPNET and desmoplastic small round cell tumor in the spectrum of tumors with EWS gene rearrangements. Other tumors with different histopathologic features and an EWS gene rearrangement are discussed elsewhere in this volume.

Ewing sarcoma/primitive neuroectodermal tumor arising from the adrenal gland in an adolescent

We review the case of an adolescent who presented with flank pain, fatigue and a discrete nonfunctioning adrenal lesion which was found to be an adrenal Ewing sarcoma/primitive neuroectodermal tumor (ES/PNET). The patient was treated with a minimally invasive adrenalectomy as a component of multimodal therapy, including seven courses of chemotherapy and whole abdominal radiation. She is currently disease free 14 months after the operation and 3 months off therapy.

[Ewing's sarcoma of the kidneys with simultaneous seminoma]

Extraosseous Ewing's sarcoma (EOE) is rarely observed in the urinogenital tract, which results in only sporadic descriptions of primary EOE of the kidneys in the literature with cytologic analyses. A timely diagnosis and differentiated therapy of this aggressive disease are compromised by its infrequent appearance and scarce available data. With a simultaneously diagnosed seminoma our case report supports and extends further the data collected so far.

Clinical features and outcomes in patients with extraskeletal Ewing sarcoma

BACKGROUND

Ewing sarcoma can arise in either bone or soft tissue. The purpose of this study was to investigate whether patient characteristics, treatment strategies, and outcomes differ between skeletal Ewing sarcoma and extraskeletal Ewing sarcoma (EES).

METHODS

Patients <40 years of age with Ewing sarcoma or peripheral primitive neuroectodermal tumor reported to the United States Surveillance, Epidemiology, and End Results Program database from 1973 to 2007 were evaluated based on skeletal (n = 1519) versus extraskeletal (n = 683) site of origin. Patient characteristics were compared using Fisher exact tests. Overall survival was estimated via the Kaplan-Meier method and compared using log-rank tests and Cox proportional hazard models.

RESULTS

Patients with EES had a higher mean age (19.5 vs 16.3 years; P < .001) and were less likely to be male (53.4% vs 63.3%; P < .001) or white (84.8% vs 92.5%; P < .001) compared with patients with skeletal tumors. Extraskeletal tumors were more likely to arise in axial locations (72.9% vs 54.2%; P = .001) but were less likely to arise specifically in the pelvis (19.8% vs 26.6%; P < .001). Metastatic status or tumor size did not differ by group. Five-year overall survival was superior for localized EES compared with localized skeletal tumors (69.7% vs 62.6%; P = .02). The hazard ratio for death in patients with localized skeletal tumors compared with localized EES was 2.36 (95% confidence interval, 1.61-3.44) beyond 24 months from initial diagnosis.

CONCLUSIONS

Patient characteristics and outcomes differ among patients with EES compared with patients with skeletal Ewing sarcoma. These findings may have important implications for patient care.

Fine-needle aspiration cytology of primitive neuroectodermal tumor of the urinary bladder: a case report

Primitive neuroectodermal tumors (PNETs) are malignant small round cell tumors, which exhibit a variable degree of neural differentiation. These tumors are usually found in the extraosseous soft tissue and rarely in bones. Occasional cases of PNETs of the urinary bladder have been reported on histopathology. However, to the best of our knowledge, none have been diagnosed on fine-needle aspiration cytology (FNAC). A patient presented to the out-patient department with complaints of a slowly progressive lump in the lower abdomen, which was diagnosed as PNET on FNAC. The smears showed a dispersed population and sheets of malignant small round cells with focal rosette formation and perivascular arrangement of tumor cells. Periodic acid-Schiff staining showed strong cytoplasmic positivity. Immunocytochemistry of the cytology smears also showed strong membrane positivity for CD99 (MIC-2), which was also confirmed on histopathological examination. PNET of the urinary bladder is a distinct entity, which can be diagnosed on FNAC and confirmed by immunohistochemistry. A diagnosis of PNET should be considered as a differential diagnosis in urinary bladder masses, especially in adolescents and young adults.

Peripheral primitive neuroectodermal tumor of head-neck region: our experience

To present four rare cases of peripheral primitive neuroectodermal tumors of different sites of head and neck region. Four cases of different age (range 8-40 years) and sex (three female, one male) with rare primitive neuroectodermal tumor of sinonasal region and neck are presented. Treatment options, biological behavior and prognostic outcome are discussed herewith. Two patients succumbed to the disease within four to six months of treatment; other two patients are still under follow-up depicting the aggressive nature of the tumor. Primitive neuroectodermal tumor belongs to the class of malignant round cell tumor. Immunohistochemistry plays a pivotal role in differentiating this tumor entity. Chemoradiation was tried, but local and systemic spread occurs early and holds poor prognosis. This case series is an attempt to describe the aggressive behavior of this rare tumor with high mortality.

[Askin tumor: a case report with literature review]

Askin tumor is a rare malignant tumor arising from soft tissues of the chest wall, rarely in the lung. It occurs predominantly in young adults. It still raises many questions about its individualisation and its links with Ewing's sarcoma. We report a case of Askin tumor in a 5-year-old child with reviewing the different data from the literature.

Primitive neuroectodermal tumor of the kidney in an adult: a case report

INTRODUCTION

Primitive neuroectodermal tumors (PNETs) occur predominantly in childhood preferentially in the soft tissues of the lower extremity and the paraspinal region. We present here a rare case of a PNET of the kidney in an adult.

CASE PRESENTATION

A tumor adjacent to the right kidney was detected by ultrasound coincidentally at a routine check-up in a 46-year-old woman with irritable bowel syndrome in her medical history. The patient had no clinical signs. Contrast-enhanced computerized tomography scan of the abdomen demonstrated a highly vascularized renal tumor. A retroperitonealectomy with en-bloc resection of the kidney was performed, and histopathological work-up showed a primitive neuroectodermal tumor of the kidney with the characteristic translocation t(11;22)(q24;q12).

CONCLUSION

This tumor entity must be accurately distinguished from other renal neoplasms because of the prognostic and therapeutic impact.

Primitive Neuroectodermal Tumor of the Kidney with Hyaline Cells

Primitive neuroectodermal tumor (PNET) of the kidney is a rare disease with high malignant potential. It affects young adults and has the tendency towards early metastasis. Relying on recently available immunohistochemistry and cytogenetic investigations, today most authors define PNET as part of the same nosologic entity as Ewing's sarcoma. We present the case of a 22-year-old man with a PNET arising from the kidney with, to our knowledge, a previously undescribed finding of hyaline cells within the tumor.

Primitive neuroectodermal tumor of the kidney: a single institute series of 16 patients

OBJECTIVES

Primitive neuroectodermal tumor (PNET) of the kidney is a rare entity, the diagnosis usually being made at histopathology. Few cases reported in literature revealed a variable presentation and an aggressive behavior. The purpose of our study was to review our experience in diagnosis and the management of patients with renal PNET.

METHODS

The records of 16 patients of renal PNET treated between 1995 and 2003 were reviewed retrospectively and our data compared with the literature.

RESULTS

There were 10 male and 6 female patients with median age of 27 years. At presentation, 10 patients (63%) had localized disease, 5 (31%) had metastatic disease and 1 (6%) had locally advanced disease. The presence of Homer-Wright type rosettes on hematoxylin and eosin staining and CD99 (cluster differentiation) products positivity on immunohistochemistry supported the diagnosis. Radical nephrectomy was performed in operable cases and all patients received chemotherapy. Nine patients received adjuvant radiotherapy to the renal bed. Median follow-up was 31 months (range 4 to 92). Overall median survival was 40 months with 3- and 5-year survival of 60% and 42%, respectively.

CONCLUSIONS

The diagnosis of renal PNET must be considered in young patients presenting with renal mass. Standard therapy consists of combination of surgical resection, postoperative irradiation and chemotherapy. Chemotherapy regimen used is either RCT II (round cell tumor) protocol or EFT 2001 (Ewing's family of tumors) protocol. However, further studies are required to validate the appropriate chemotherapy protocol.

Superficial primitive neuroectodermal tumor/Ewing sarcoma (PN/ES): same tumor as deep PN/ES or new entity?

Primitive neuroectodermal tumor/Ewing sarcoma (PN/ES) is a single clinical, morphologic, and molecular small round cell tumor entity. These are generally found in deep soft tissue or bone of young male patients, with poor behavior. Location in dermis is unexpected; only rare cases are reported. Cases coded as "dermal," "cutaneous," or "skin" PN/ES were retrieved from our consultation files. Only primary dermal cases were included. Those otherwise diagnosed or with incomplete material were excluded. There were 13 dermal PN/ES cases, consisting of 10 women and 3 men. Ages ranged from 2 to 67 years (mean, 28 years). Locations included groin or thigh (4), back or shoulder (3), neck (1), chest (1), scalp (1), forehead (1), hand (1), and foot (1). Most cases were small (0.5-2.3 centimeters) and painful, and persisted for less than 1 year. All were located within the dermis. Three caused pedunculation; 9 also involved superficial subcutis. All but 1 of the metastasizing tumors were round and encapsulated. All were composed of round to oval cells with a vague rosetting pattern, slightly overlapping nuclei, finely stippled chromatin, clear to eosinophilic cytoplasm, and collagenous stroma. Median mitotic activity was 8 per 10 high-power fields. Necrosis was present in three cases. All had globular periodic acid Schiff positivity and distinctive cytoplasmic membrane CD99 reactivity. One case studied was positive for Fli-1. All were negative for leukocyte common antigen, Tdt, CD3, CD20, CD79, CK20, pankeratin, epithelial membrane antigen, chromogranin, neurofilament protein, carcinoembryonic antigen, desmin, actin, diffuse S100 protein, and HMB45. Nine cases with material for reverse transcription-polymerase chain reaction revealed 1 positive type 2 translocation (EWS exon 7 to Fli-1 exon 5), 4 negative, and 4 "unable to amplify." Treatment was by wide excision; 9 received chemotherapy and 6 radiation. Follow-up of 11 (85%) cases revealed the following: 1 metastasis to stomach and death at 3 years; 10 years without disease (median, 9.0 years). Cutaneous PN/ES is a superficial round cell tumor in older women, with better prognosis than deep PN/ES. These may have a hitherto unrecognized variant genetic abnormality.

Malignant peripheral primitive neuroectodermal (pPNET) of tongue

Primitive neuroectodermal tumors (PNETs) are relatively rare tumors. Tumors that once would have been diagnosed as Ewing's sarcoma are now often designated as peripheral neuroepithelioma or synonymously PNET. This paper reports a case of PNET located orally on the tongue, which is, to our knowledge, the first case reported in medical literature. The patient was treated with postoperative radiotherapy and chemotherapy. Multiple liver metastases occurred 5 months after the initial diagnosis and following extensive chemotherapy the patient was only able to survive for a further 10 months.

Ewing sarcoma family of tumors in unusual sites: confirmation by rt-PCR

Ewing sarcoma family tumors originating in the palate or adrenal gland are extremely rare and may cause difficulty in diagnosis. More common tumors primary to these sites need to be excluded before one arrives at the correct diagnosis. We have recently diagnosed 2 such cases. The 1st case was that of a 24-year-old woman who presented with a swelling in the right side of the hard palate. The 2nd case was diagnosed in a 28-year-old woman who presented with a mass in the right adrenal gland. In both cases, the diagnosis of Ewing sarcoma family of tumors was confirmed by immunohistochemical studies and reverse transcriptase-polymerase chain reaction (RT-PCR). The hard palate case is the 1st and the adrenal gland the 3rd case of Ewing sarcoma family of tumors arising in these sites, in which the diagnosis was confirmed by RT-PCR and/or cytogenetics. Accurate diagnosis of Ewing sarcoma family of tumors is crucial for the management of patients, and when found in such rare locations, diagnosis should be supported by immunohistochemical and/or molecular genetic studies.

Primitive neuroectodermal tumor: rare, highly aggressive differential diagnosis in urologic malignancies

OBJECTIVES

Peripheral primitive neuroectodermal tumor (PNET) is a highly aggressive neoplasm belonging to the Ewing family of tumors. It is characterized by the expression of MIC2 and neural markers (eg, neuron-specific enolase, synaptophysin, S-100, vimentin, Leu-7), and the presence of the EWS-FLI1 translocation.

METHODS

We performed a MEDLINE search for PNET in urologic malignancies. Additionally, we report on 2 cases of renal and 1 case of bladder PNET. The data obtained by reviewing patients with renal PNET were analyzed using Kaplan-Meier analysis.

RESULTS

Renal PNET is diagnosed in young adults (median age 24 years). In contrast, the incidence of bladder PNET seems to be dependent on a defective immune mechanism. Patients often present with pain (84%), palpable tumor (60%), and hematuria (38%). The radiologic findings are uncharacteristic; therefore, the diagnosis should be based on the histologic and immunohistochemistry findings. Renal and bladder PNET are both often diagnosed at an advanced stage and, therefore, the prognosis is poor, despite aggressive multimodal treatment (surgery, polychemotherapy, radiotherapy). We identified palpable tumor masses (log-rank test, P = 0.0027) and synaptophysin expression (log-rank test, P = 0.0422) as prognostic unfavorable markers for renal PNET.

CONCLUSIONS

Renal PNET should be considered in young patients who present with the classic triad of renal cancer, hematuria, and pain and palpable tumor. Once PNET is diagnosed, multimodal treatment (radical surgery, multidrug chemotherapy, radiotherapy) must be initiated. Despite this, the prognosis is poor if distant metastases are present. Furthermore, palpable tumor masses and synaptophysin expression are associated with a shorter cancer-specific survival.

Peripheral Primitive Neuroectodermal Tumor of the Cavernous Sinus: Case Report

OBJECTIVE:

Ewing sarcoma/peripheral primitive neuroectodermal tumors (pPNET family) are small, round, blue cell tumors that have a decided predilection for young patients and commonly arise in bone and soft tissue. We are reporting a rare case of cavernous sinus pPNET in a 48-year-old woman.

CLINICAL PRESENTATION:

A 48-year-old woman presented with headache, ipsilateral maxillary, and ophthalmic and oculomotor nerve palsies. Neuroimaging revealed a cavernous sinus lesion.

INTERVENTION:

The patient underwent debulking of the tumor, and the diagnosis of a pPNET was made based on histological, immunohistochemical, and molecular genetics (EWS-FLI1 fusion gene) findings. Bone scans, bone marrow aspiration, and biopsy and chest computed tomographic scans showed no evidence of systemic involvement. The patient had adjuvant treatment with radiotherapy and chemotherapy. After 14 months, the patient had no neurological deficits, and neuroimaging showed stable disease, although some chemotherapy complications occurred.

CONCLUSION:

This is a case of cavernous sinus pPNET in a 48-year-old woman, in whom the diagnosis is supported by the presence of EWS-FLI1 fusion gene. This seems to be the first reported case of a cavernous sinus pPNET confirmed by molecular genetic analysis.

Tumeur neuro-ectodermique primitive orbitaire avec extension endocrânienne

Primitive neuroectodermal tumor (PNET) of the orbit is rare. We present a case of a young patient with orbital PNET extending to the endo-crane and sinuses, which had been treated 10 years before with the diagnosis of rhabdomyosarcoma. The diagnosis was corrected with immunohistochemistry. Through this observation, we discuss the clinical aspects, the diagnosis difficulties, and the therapeutic options of this rare affection.

Primitive neuroectodermal tumor of the head and neck: incidence, diagnosis, and management

Primitive neuroectodermal tumors are in the Ewing's sarcoma family of tumors and are composed of small round cells. Because of their rare occurrence, optimal therapy is challenging, particularly if they occur in the head and neck. Diagnosis is based on history, immunostaining with at least 2 neural markers, ultrastructural examination, and evidence of an abnormal t(11;22)(q24;q12) translocation as the hallmark for the Ewing's sarcoma family. The prognosis in general is poor because of overt metastasis at the time of diagnosis. Of 27 reported patients with primitive neuroectodermal tumors of the head and neck, 23 were less than 20 years of age. Most patients presented with a tumor in the nasal cavity, paranasal sinuses, or neck. Symptoms developed rapidly (3.6 months, on average), and a lethal outcome occurred in 9 patients. This highly malignant tumor requires an aggressive combination of radical resection, chemotherapy, and radiotherapy. A close follow-up with regular radiographic examination for at least 5 years is mandatory.

Malignant peripheral primitive neuroectodermal tumor-peripheral neuroepithelioma of the head and neck: a clinicopathologic study of five cases and review of the literature

BACKGROUND

The term primitive neuroectodermal tumor (PNET) encompasses a number of neoplasms of common neuroectodermal origin, but of variable clinical, histopathologic, ultrastructural, and molecular characteristics. Here, we focus on one particular member of the PNET family, the malignant peripheral PNET (pPNET) or peripheral neuroepithelioma of head and neck.

METHODS

Five patients diagnosed with malignant pPNET-peripheral neuroepithelioma of head and neck were included in the study. All existing literature was reviewed.

RESULTS

The diagnosis of malignant pPNET-peripheral neuroepithelioma of the head and neck was confirmed in all five cases. All patients are alive after treatment with a combination of therapeutic modalities; only one patient had metastatic disease develop. A literature review revealed another 38 reported cases.

CONCLUSIONS

Malignant pPNET-peripheral neuroepithelioma should be included in the differential diagnosis of small, round, blue cell tumors of head and neck. A combination of multiple diagnostic modalities is essential for correct diagnosis, and multimodality treatment offers the best outcome.