Extracerebellar primitive neuroectodermal tumors: A clinicopathologic study with bcl-2 and CD99 immunohistochemistry

A mesenteric primary peripheral Ewing's sarcoma/primitive neuroectodermal tumor with molecular cytogenetic analysis: Report of a rare case and review of literature

Rare cases of Ewing's sarcoma/primitive neuroectodermal tumors (EWS/PNETs) arising from mesenteric tissue have been reported. This report describes an EWS/PNET in a 25-year-old woman who presented with abdominal pain lasting 3 days. Radiologic evaluation revealed a 9 cm × 6 cm homogeneous mass in the lower abdomen with homogeneous enhancement and invasion of the ileum. Surgical resection was completed during exploratory laparotomy. Immunohistochemically, the tumor cells revealed CD99, friend leukemia virus integration-1 and NKX2.2 (NK2 Homeobox 2, a protein coding gene) and subsequently showed EWSR1 rearrangement. The histological feature, immunohistochemical results and genetic fluorescence in situ hybridization analysis of this case were confirming the diagnosis of EWS/PNET. Adjuvant chemotherapy was suggested, but the patient was lost to follow-up.

A supratentorial primitive neuroectodermal tumor presenting with intracranial hemorrhage in a 42-year-old man: a case report and review of the literature

Introduction

We report on a very rare case of a supratentorial primitive neuroectodermal tumor in an adult, which presented with intracerebral hemorrhage, and review the relevant medical literature.

Case presentation

A 42-year-old Caucasian man complained of a sudden headache and nausea-vomiting. The patient rapidly deteriorated to coma. An emergency computed tomography scan showed an extensive intraparenchymal hemorrhage that caused significant mass effect and tonsilar herniation. During surgery, an increased intracranial pressure was recorded and extensive bilateral decompressive craniectomies were performed. A cherry-like intraparenchymal lesion was found in his right frontal lobe and resected. The patient died in the intensive care unit after approximately 48 hours. The resected lesion was identified as a central nervous system primitive neuroectodermal tumor.

Conclusion

Supratentorial primitive neuroectodermal tumors must be considered in the differential diagnosis of space-occupying lesions in adults. Spontaneous supratentorial hemorrhage due to primitive neuroectodermal tumors is an extremely rare but potentially lethal event.

Supratentorial primitive neuroectodermal tumor in an adult: a case report and review of the literature

INTRODUCTION

Supratentorial primitive neuroectodermal tumors predominantly occur in children, and are rare in the adult population. Less than 100 cases of supratentorial primitive neuroectodermal tumor have been reported in adults internationally. Our case study reports this rare incident.

CASE PRESENTATION

A 22-year-old Hispanic man presented with headaches, blurry vision, diplopia, intermittent vomiting, and grossly decreased vision. A magnetic resonance image showed a left posterior parietal heterogeneously enhancing mass measuring 4.2cm × 7.2cm × 7.0cm. After craniotomy for resection and decompression, the mass was histologically revealed to be a supratentorial primitive neuroectodermal tumor. Standardized immunohistochemical studies for this mass were carried out.

CONCLUSION

We have concluded that immunohistochemical and genetic workup should be included in the standardized pathological workup for primitive neuroectodermal tumors in order to provide more prognostic information. Based on our current literature review, we propose an immunohistochemical panel.

Primary spinal extradural Ewing's sarcoma (primitive neuroectodermal tumor): Report of a case and meta-analysis of the reported cases in the literature

Background:

Primary spinal primitive neuroectodermal tumors (PNET) and/or spinal extraskeletal Ewing's sarcoma family tumors (ESET) are rare lesions appearing in the spinal extradural space. One hundred forty-one primary spinal PNETs, including 29 intramedullary lesions, have been reported in the literature. Encountering a case of primary epidural EES/peripheral PNET (pPNET) in sacral level, which is the fifth one occurring at this level in the literature, we have tried to conduct a meta-analysis of the reported cases.

Case Description:

A 44-year-old lady with epidural EES/pPNET is reported here. She was once operated for L5/S1 herniated disc, which did not ameliorate her symptoms. The clinical, imaging, surgical, and histopathologic characteristics of our case are presented and wide search of the literature is also done. All the reports were level 3 or less evidences and most of the series had missing parts. 106 cases of primary intraspinal (extradural/extramedullary-intradural) EES/pPNET and 29 cases of primary intramedullary PNET (CNS-PNET) have been reported in the literature. The most common clinical presentation in both entities was muscle weakness proportionate to the tumor location. Distant metastasis occurred in 38 of 99 (38%) cases of primary intraspinal EES/pPNET, while the rate of metastasis was 48% in patients with PNETs occurring in the intramedullary region (P > 0.05). One-year survival rate of the patients who underwent chemo-radiation after total or subtotal resection was better than those who did not receive chemotherapy or radiotherapy, or did not have total or subtotal resection. However, this difference was not repeated in 2-year survival rate in any of the tumor groups.

Conclusion:

It seems that total or subtotal removal of the tumor and adjuvant chemo- and radiation therapy can improve the outcome in these patients.

Primitive neuroectodermal tumors of the spine: a comprehensive review with illustrative clinical cases

Primary spinal primitive neuroectodermal tumors (PNETs) are uncommon malignancies that are increasingly reported in the literature. Spinal PNETs, like their cranial counterparts, are aggressive tumors and patients with these tumors typically have short survival times despite maximal surgery, chemotherapy, and radiation. Because no standard management guidelines exist for treating these tumors, a multitude of therapeutic strategies have been employed with varying success. In this study the authors perform a comprehensive review of the literature on primary spinal PNETs and provide 2 new cases that highlight the salient features of their clinical management.

A Primary Extraosseous Ewing Sarcoma in the Cerebellopontine Angle of a Child: Review of Relevant Literature and Case Report

BACKGROUND AND IMPORTANCE:

We report the occurrence of a primary intracranial extraosseous Ewing sarcoma/peripheral primitive neuroectodermal tumor (EES/pPNET) in the cerebellopontine angle in a child.

CLINICAL PRESENTATION:

A 10-year-old girl presented with symptoms and signs of an infratentorial space-occupying lesion that was confirmed by magnetic resonance imaging and followed up by subtotal surgical resection. Tumor cells displayed membranous expression of CD99, and one of the typical translocations of EES/pPNET (chromosome 22) was demonstrated by cytogenetic analysis.

CONCLUSION:

The literature regarding the histopathological, molecular, radiological, prognostic, and therapeutic features of intracranial EES/pPNET is reviewed, emphasizing the distinction of this entity from the central PNET. Although exceptionally rare, intracranial EES/pPNET should be considered in the differential diagnosis of lesions in the cerebellopontine angle.

Primary vaginal Ewing's sarcoma or primitive neuroectodermal tumor in a 17-year-old woman: a case report

Introduction

Primary Ewing's sarcoma or primitive neuroectodermal tumor of the genital tract of women is uncommon. Rarer still is its occurrence in the vagina, with only five cases described so far. Out of these, only one case was confirmed using molecular analysis.

Case presentation

We present an extremely rare case of Ewing's sarcoma or primitive neuroectodermal tumor in a 17-year-old Indian girl. She presented with a vaginal mass that was initially diagnosed as a malignant round cell tumor. Immunohistochemistry showed diffuse positivity for vimentin, membranous positivity for MIC2, and positivity for BCL2 and FLI-1. On the other hand, she was negative for cytokeratin, epithelial membrane antigen, desmin, Myo D-1, myogenin and smooth muscle actin. A diagnosis of primitive neuroectodermal tumor was thus offered. Furthermore, a molecular analysis of our patient using reverse transcription-polymerase chain reaction technique showed positivity for t(11; 22) (q24; q12) (EWSR1-FLI1), thus confirming the diagnosis of a Ewing's sarcoma/primitive neuroectodermal tumor. Our patient was offered chemotherapy on Institutional protocol EFT 2001.

Conclusion

This is a rare case of primary vaginal Ewing's sarcoma or primitive neuroectodermal tumor, which was confirmed with molecular analysis, in the youngest patient known so far. This study reinforces the value of integrating morphological features with membranous MIC2 positivity, along with application of molecular techniques in objective identification of an Ewing's sarcoma or primitive neuroectodermal tumor at uncommon sites.

Case Report: Intracranial peripheral primitive neuroectodermal tumor - Ewing's sarcoma of dura with transcalvarial-subgaleal extension: An unusual radiological presentation

The occurrence of the intracranial, peripheral, primitive, neuroectodermal tumor, Ewing's sarcoma (pPNET-ES) of the dura, is very rare. Immunophenotypical as well as genetic analyses play key roles in its diagnosis and differentiation from central PNET. We describe here the CT scan and MRI findings of an interesting case of intracranial pPNET-ES arising from the anterior falx cerebri with a trancalvarial-subgaleal extension.

A supratentorial primitive neuroectodermal tumor in an adult: a case report and review of the literature

Supratentorial primitive neuroectodermal tumors (sPNET) occurring in adults are rare. Only 56 such cases have been previously reported. This report documents a 56-year-old male who presented with the chief complaint of right facial palsy. Magnetic resonance imaging (MRI) revealed left frontal and bilateral periventricular lesions. Surgery was performed for the frontal mass, which was histologically diagnosed to be sPNET. An immunohistochemistry assay for CD99, and a fluorescence in situ hybridization (FISH) assay for t(11;22) translocation revealed this PNET to be a central PNET. This case was the first case to detect a central PNET using both immunohistochemistry and the FISH assay in adult sPNET. Though radiation therapy was performed, an MRI performed 2.5 months after the surgery revealed a regrowth of the tumor. The patient died 5 months after surgery. This case report is accompanied by a review of 57 cases of adult sPNET.

Primitive supratentorial neuroectodermal tumor in an adult

We report the case of a 32-year-old female with a diagnosis of supratentorial tumour. Total removal of the tumour was achieved in a two-stage procedure. Histopathology revealed a primitive neuroectodermal tumour (PNET), an unusual and highly malignant, mainly infratentorial tumour of childhood that is uncommonly described in the supratentorial compartment of adults. We review the literature and describe the existing knowledge of these tumours.

Peripheral primitive neuroectodermal tumor/Ewing's sarcoma of the craniospinal vault: case reports and review

The peripheral primitive neuroectodermal tumor/Ewing's sarcoma family tumor (pPNET/ESFT) group includes small round cell tumors of the bone, soft tissue, and nerve with morphological attributes of the germinal neuroepithelium. Peripheral PNETs/ESFTs also occur within the craniospinal vault, a region including the central nervous system, the meninges, and the cranial and spinal nerve roots. Gene rearrangements between the EWS gene on chromosome 22q12 and members of the ETS gene family are common in and specific to pPNETs/ESFTs. Another defining characteristic of pPNETs/ESFTs is their membranous expression of the MIC2 gene product. We describe 2 cases of pPNETs within the craniospinal vault. An intradural tumor arising from the nerve roots of the cauda equina was discovered in a 32-year-old man presenting with radiculopathic back pain and lower-extremity weakness. An intracranial pPNET that mimicked a meningioma was found in a 21-year-old man presenting with headache and visual disturbances. MIC2 gene product expression and EWS/ETS gene rearrangement were detected in both case patients. The literature with regard to pPNETs/ESFTs arising within the craniospinal vault is reviewed.

Supratentorial primitive neuroectodermal tumours of the brain: multidirectional differentiation does not influence prognosis. A clinicopathological report of 18 patients

AIMS

To examine the clinical and pathological characteristics of supratentorial primitive neuroectodermal tumours (PNETs) in a retrospective series of 18 patients, according to the strict definition of the World Health Organization classification of tumours that excludes other types of malignant embryonal tumours of the brain.

METHODS AND RESULTS

Eleven children and seven adults with supratentorial PNETs were diagnosed between 1993 and 2002 and their medical records were reviewed. An immunohistochemical study was performed on formalin-fixed paraffin-embedded tissue of 18 primary tumours and five recurrences with antibodies for neuronal (neuron specific enolase, synaptophysin, neurofilament, chromogranin A), epithelial [epithelial membrane antigen (EMA), cytokeratin], glial [glial fibrillary acidic protein (GFAP)], muscle (desmin, h-caldesmon, alpha-smooth muscle actin, myogenin) differentiation and with two anti-CD99 antibodies. All tumours showed at least one neuronal marker except chromogranin A; a variable number of cells were GFAP+ or EMA+ in 18/23 tumours. Six primary tumours and one recurrence were positive for cytokeratin and/or one muscle antigen except myogenin. CD99 was observed in 33% of the cases. The mean duration of overall survival was 20 months. The estimated overall survival rates were 61% at 1 year, 29% at 2 years, and 18% at 3 years. Two factors of poor prognosis were identified by univariate analysis: a positive cerebrospinal fluid cytology at diagnosis and the absence of complete resection. No distinct immunophenotype was statistically related to survival.

CONCLUSIONS

A multidirectional differentiation is a frequent event in supratentorial PNETs but has no apparent influence on the outcome of this aggressive neoplasm.

Primary peripheral PNET/Ewing's sarcoma of the dura: a clinicopathologic entity distinct from central PNET

We describe two cases of peripheral primitive neuroectodermal tumor-Ewing's sarcoma (PNET-ES) arising intracranially in the leptomeninges. Both tumors exhibited a primitive undifferentiated round-cell morphology. Immunohistochemical stains revealed strong membrane expression of CD99 in both cases. A t(11;22)(q24;q12) could be demonstrated with reverse transcriptase-polymerase chain reaction in one case, whereas fluorescence in situ hybridization analysis performed in the second case showed a rearrangement of the EWS gene. The occurrence of PNET-ES at this site is very unusual. Immunophenotypical as well as genetic analysis play a key role in the diagnosis and the distinction from central PNET.

CD99 immunoreactivity in ependymoma

The expression of CD99 in normal ependymal cells and ependymoma has been reported. However, only limited numbers of tumors have been studied, and the pattern of CD99 expression has not been described. The authors' purpose was to investigate CD99 immunoreactivity in ependymoma and its use for differential diagnosis. Twenty-five ependymomas were immunostained with antibody directed at CD99. The result of immunostaining of ependymomas was compared with 63 nonependymal tumors that histologically resemble ependymal neoplasms. The nonependymal tumors included 19 astrocytic tumors, 6 oligodendroglial tumors, 8 choroid plexus neoplasms, 2 central neurocytomas, 5 medulloblastomas, 10 primitive neuroectodermal tumors (PNET), and 13 pituitary adenomas. All ependymomas showed strong expression of CD99 in membranous pattern with intracytoplasmic or intercellular dots (ICDs). The expression pattern of CD99 was not correlated with histologic type or grade of ependymomas. Among 63 nonependymal tumors, 11 (17.5%) showed incomplete membrane staining for CD99; diffuse in 4 PNETs and focal in 5 choroid plexus neoplasms (3 papillomas and 2 carcinomas) and one each of pituitary adenoma and oligodendroglioma. The ICD was not found in nonependymal tumors except a case of choroid plexus papilloma. However, membrane staining or ICD for CD99 was not distinctive in nonependymal tumors. In conclusion, the characteristic pattern of anti-CD99 antibody, i.e., diffuse strong membranous immunostaining with ICDs, is useful in distinguishing ependymomas from the central nervous system tumors that histologically mimic ependymoma.

Spindle cell epithelioma of the vagina shows immunohistochemical staining supporting its origin from a primitive/progenitor cell population

Spindle cell epitheliomas of the vagina (SCEVs) coexpresses epithelial and mesenchymal markers and were first described as a "mixed tumors of the vagina." However, unlike mixed tumors of other organs, which are believed to originate from myoepithelial cells, SCEVs neither immunohistochemically nor ultrastructurally show features of myoepithelial cells. The present expanded battery of immunohistochemical stains is presented on this rare tumor, including cytokeratin AE1/AE3, CK7, CK20, S100 protein, epithelial membrane antigen, alpha-smooth muscle actin, desmin, CD34, CD99, Bcl-2, vimentin, estrogen and progesterone receptors, and Ki-67. There was minimal expression of alpha-smooth muscle actin and negative staining with S100 protein, with coexpression of cytokeratins and vimentin and expression of estrogen and progesterone receptors, as previously reported in SCEVs. In addition, diffuse expression of CD34, CD99, and Bcl-2 immunohistochemical stains was found, which has not previously been reported. The coexpression of CD34, CD99, and Bcl-2 in SCEVs is consistent with its origin from a primitive/progenitor cell population.