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Fine needle aspiration of peripheral neuroepithelioma of soft tissues.

Peripheral neuroepithelioma of soft tissue is a malignant primitive neuroectodermal tumor that appears both in children and adults and usually has a poor outcome. Fine needle aspiration on two patients with tumors in the lower limbs showed small round cells with unipolar processes and a tendency to form Homer-Wright rosettes. The cells had a round to oval nucleus with fine chromatin, up to four small, conspicuous nucleoli and vacuolated, periodic acid-Schiff-positive cytoplasm. The diagnosis was supported by electron microscopic study of the aspirate, which showed features of neuroblastic differentiation (i.e., neurosecretory granules), and by histologic, immunohistochemical and cytogenetic study of the resected tumors.

Adolescent↗

A splice variant of the neuron-restrictive silencer factor repressor is expressed in small cell lung cancer: a potential role in derepression of neuroendocrine genes and a useful clinical marker.

The neuron-restrictive silencer factor [NRSF (RE-1 silencing transcription factor/X box repressor)] is a transcriptional silencer, which we have previously implicated in deregulation of the vasopressin promoter in small cell lung cancer (SCLC). Here we describe a novel splice variant of the NRSF transcript, which is highly expressed in SCLCs. The variant was detected in both established cell lines and primary SCLC cultures as well as in some primitive neuroectodermal tumor biopsies. It was present at very low levels in human brain tissue, non-SCLC tumors, and normal bronchial epithelium. This human splice variant, which is massively overexpressed in SCLCs, incorporates a 50-bp insert between exons 5 and 6, introducing a stop codon and predicting translation of a truncated NRSF isoform. We propose that the encoded isoform may antagonize repression of the vasopressin promoter and other "neuronal" genes with neuron-restrictive silencer elements in SCLCs. Thus, up-regulated expression of this NRSF isoform may be a key early factor in defining the neuroendocrine phenotype of these tumors. The NRSF splice variant represents a specific clinical marker that could prove useful in detection of the majority of SCLCs.

Alternative Splicing↗

Cdk9 regulates neural differentiation and its expression correlates with the differentiation grade of neuroblastoma and PNET tumors.

Cdk9 is a member of the Cdc2-like family of kinases. Its cyclin partners are members of the family of cyclin T (T1, T2a and T2b) and cyclin K. The Cdk9/Cyclin T complex appears to be involved in regulating several physiological processes. Recently, Cdk9 has been identified as a regulator of the differentiation program of several cell types, such as muscle cells, monocytes and lymphocytes, suggesting that it may have a function in controlling specific differentiative pathways. We analyzed whether Cdk9 and Cyclin T1 may be involved in the regulation of neuron and astrocyte differentiation. Cdk9 and Cyclin T1 expression levels were monitored during the differentiation program of neuroblastoma and astrocytoma cell lines. Our results suggest that Cdk9/Cyclin T1 complex may be required for neuron differentiation induced by retinoic acid, because the expression level of the complex varies during differentiation, but no significant changes were observed in its expression in the astrocytoma cell line. In addition, the expression of Cdk9 and Cyclin T1 was evaluated by immunohistochemistry in samples of neuroblastoma, PNET (Primary Neuroectodermal Tumor) and astrocytoma tumors of different grades, in order to assess whether there was a correlation between Cdk9 expression and tumor grading. Our results show that in neuroblastoma and PNET tumor samples Cdk9 is more expressed the more differentiated the tumor is. Conversely, no significant alteration of Cdk9 expression was observed in astrocytoma tumor samples of different grades, thus confirming the results obtained for the cell lines.

Astrocytes↗

Olfactory neuroblastoma with spinal metastasis--a problem in diagnosis.

The olfactory neuroblastoma or esthesioneuroblastoma is a rare neuroectodermal tumor originating from the olfactory neuroepithelium, which can metastasis via cerebrospinal fluid pathways. In the present case of an extensive nasal malignancy with cervical lymph node metastases in a 75-year old woman, its difficult histology alternatively led to a diagnosis of anaplastic carcinoma and non-Hodgkin lymphoma. The patient died from complications following spread of the tumor to the spinal cord and cauda equina. Review of the literature shows that this tumor is notorious for its chameleonic character. In view of its clearly demonstrated malignancy an aggressive therapeutic approach is advocated.

Aged↗

Cerebellar degeneration and autoimmunity to zinc-finger proteins of the cerebellum.

The serum of a patient with subacute cerebellar dysfunction was used to probe a cDNA expression library and isolate two genes: Zic1 (zinc-finger of the cerebellum) and Zic4. The patient had intrathecal synthesis of Zic antibodies, suggesting that the Zic proteins were autoantigens of the neurologic disorder. The Zic proteins are involved in cerebellar development and are reported as being preferentially expressed by medulloblastomas. It was found that the expression of Zic proteins is enriched in, but not limited to, medulloblastomas and primitive neuroectodermal tumors.

Aged↗

Multiagent chemotherapy and deferred radiotherapy in infants with malignant brain tumors: a report from the Children's Cancer Group.

PURPOSE: To evaluate response rate, event-free survival (EFS), and toxicity of two chemotherapeutic regimens for treatment of children younger than 36 months with malignant brain tumors and to estimate control intervals without irradiation in children with no residual tumor after initial surgery and induction chemotherapy and with delayed irradiation in patients with residual tumor or metastatic disease at diagnosis. PATIENTS AND METHODS: Patients were randomly assigned to one of two regimens of induction chemotherapy (vincristine, cisplatin, cyclophosphamide, and etoposide v vincristine, carboplatin, ifosfamide, and etoposide). Maintenance chemotherapy began after induction in children without progressive disease. Children with no residual tumors after induction therapy and no metastatic disease at diagnosis were not to receive radiation therapy unless their tumors progressed. RESULTS: Two hundred ninety-nine infants were enrolled. Forty-two percent of patients responded to induction chemotherapy. At 5 years from study entry, the EFS rate was 27% +/- 3%, and the survival rate was 43% +/- 3%. There was no significant difference between the two arms in terms of response rate or EFS. For medulloblastoma, supratentorial primitive neuroectodermal tumor, ependymoma, and rhabdoid tumors, 5-year EFS rates were 32% +/- 5%, 17% +/- 6%, and 32% +/- 6%, and 14% +/- 7%, respectively. Fifty-eight percent of patients who were alive 5 years after study entry had not received radiation therapy. CONCLUSION: Intensified induction chemotherapy resulted in a high response rate of malignant brain tumors in infants. Survival was comparable to that of previous studies, and most patients who survived did not receive radiation therapy.

Antineoplastic Combined Chemotherapy Protocols↗

Outcome for children <4 years of age with malignant central nervous system tumors treated with high-dose chemotherapy and autologous stem cell rescue.

BACKGROUND: Children <4 years of age (yo) with malignant central nervous system (CNS) tumors have a dismal prognosis. In an attempt to delay or obviate radiation therapy (XRT) and improve outcome, our institution has treated children <4 yo with newly diagnosed malignant CNS tumors with high-dose chemotherapy (HDC) and autologous stem cell rescue (ASCR) followed by selective XRT. PROCEDURE: Fifteen children (age 4-38 months) with malignant CNS tumors have completed treatment with HDC/ASCR. All patients received three cycles of induction chemotherapy (cisplatin 3.5 mg/kg- day 0, cyclophosphamide 60 mg/kg- day 1 and 2, etoposide 2.5 mg/kg- day 0-2, vincristine 0.05 mg/kg, day 0, 7, 14) followed by three cycles of HDC (carboplatin 17 mg/kg and thiotepa 6 mg/kg, day 0 and 1) with ASCR. Histology included five medulloblastomas, four primitive neuroectodermal tumors (PNET), five malignant gliomas, and one ependymoma. Outcome and treatment toxicities were evaluated by retrospective chart review. RESULTS: Median follow-up time of the 15 patients is 22 months (range 8-82 months). The 1- and 2-year progression-free survival (PFS) is 86.1% and 52.2% and overall survival (OS) 91.6% and 72.1%, respectively. Ten patients are alive and disease free 3-77 months (median 18 months) after having completed HDC/ASCR, thereoff five received XRT. Toxicity was primarily myelosuppression. There was no treatment mortality. CONCLUSIONS: We are encouraged by the outcome of 15 children <4 yo with malignant CNS tumors treated with tandem cycles of HDC and ASCR at our institution. The treatment regimen is relatively well tolerated.

Antineoplastic Combined Chemotherapy Protocols↗

Predictive potential of testing for bone marrow involvement in Ewing tumor patients by RT-PCR: a preliminary evaluation.

EWS/ets-oncogene fusion transcripts can be detected in at least 98% of Ewing tumors [(ET) Ewing sarcoma and peripheral primitive neuroectodermal tumor] by reverse transcriptase-polymerase chain reaction (RT-PCR), thus confirming the histopathologic diagnosis. To detect minimal amounts of tumor cells in the bone marrow (BM), we used an RT-PCR assay with a high sensitivity, revealing one tumor cell in a background of 10(6) normal cells. We examined BM samples from 35 newly diagnosed ET patients (23 with localized and 12 with metastatic disease). At diagnosis, tumor cells in the BM were detected in 7/23 patients with localized disease (30%). Fifty percent of patients with isolated lung metastasis were RT-PCR positive (3/6), whereas 6/6 patients with bone metastases showed positive signals (100%). All patients with initial PCR positivity in the BM became negative during treatment. After a median follow-up of 30 months, relapses were observed in both groups of patients with localized disease (3/7 RT-PCR positive and 2/16 RT-PCR negative). The only recurrence in the group with isolated lung metastases occurred as progressive lung disease in 1 of the 2 RT-PCR-negative patients, whereas among the 6 patients with bone metastases 2 remain in complete remission. So far, RT-PCR screening for BM involvement did not allow prediction of early relapse in ET. To assess better the significance of this test in the evaluation of long-term prognosis and in monitoring the effectiveness of systemic therapy, long observation periods are warranted before it becomes a tool for treatment stratification.

Adolescent↗

Differentiation in embryonal neuroepithelial tumors of the central nervous system.

Ninety-six embryonal neuroectodermal tumors were studied histologically and immunohistologically with a panel of antibodies including glial, neuronal, epithelial, mesodermal, and myelin markers. In 71 tumors there was glial and neuronal differentiation and expression both of an S (photoreceptor) antigen and vimentin. In five tumors there was only glial differentiation and in 20 tumors only neuronal differentiation. No reactivity for myelin and epithelial markers was found. Histologic and immunohistologic findings identified various degrees of differentiation in different tumors, which was bipolar (glial and neuronal) in most tumors and unipolar in the remainder. The authors suggest that their findings may be the result of normal or aberrant oncogenic differentiation, agreeing with the nomenclature of the World Health Organization classification for these tumors with and the inclusion of a category for ependymoblastoma.

Adolescent↗

Evaluation of response to postradiation eight in one chemotherapy in childhood brain tumors.

Ten children, 3 to 15 years of age with high risk primary brain tumors were treated with postradiation 'eight in one' chemotherapy; vincristine, lomustine, procarbazine, hydroxyurea, cisplatin, cytosine arabinoside, cyclophosphamide and methylprednisolone. The tumors comprised of three medulloblastomas, two primitive neuroectodermal tumors, one ependymoblastoma and four anaplastic ependymomas. Treatment involved surgery (two total resection, six subtotal and two biopsy only) followed by conventional radiotherapy (primary tumor: 50-54 Gy, whole brain: 30-45 Gy, and spinal axis: 25-36 Gy). Objective tumor response with radiotherapy was achieved in 7 of 9 patients (78%) (6/8 patients with residual tumor and one patient with complete resection but positive cerebrospinal fluid cytology). Complete response was attained in 4 of 9 patients (44%). 'Eight in one' chemotherapy was initiated four weeks after radiation and repeated at 4 weekly intervals for 5-8 courses. Postradiation 'eight in one' failed to show any additional effect on tumor responses. Median survival was 34 months (range 9-48 months) with five of ten patients alive: four in complete and one in partial remission. All the five survivors were among the patients who had achieved response to initial treatment. This result suggested that degree of response to initial treatment might determine subsequent outcome and thus the choice of modality for initial therapy might be important.

Adolescent↗

Atypical teratoid/rhabdoid tumors.

CASE REPORTS: We describe three cases of atypical ATRT that were identified at the Children's Hospital of Eastern Ontario. DISCUSSION: Over the past decade, atypical teratoid/rhabdoid tumors (ATRTs) of the central nervous system have emerged as a distinct entity. This tumor is typically misdiagnosed as a primitive neuroectodermal tumor (PNET)/medulloblastoma. The unique immunohistochemistry profile of an ATRT helps distinguish it from a PNET/medulloblastoma. This is of clinical importance because the prognosis of a patient with an ATRT is worse than that of a PNET/medulloblastoma despite aggressive surgical treatment with or without adjuvant chemotherapy and radiation therapy.

Brain Neoplasms↗

The role of diffusion-weighted magnetic resonance imaging in pediatric brain tumors.

OBJECTIVES: Diffusion-weighted imaging (DWI) may enhance the radiographic diagnosis of pediatric brain tumors. This study reviews the DWI properties of pediatric brain tumors at our institution and examines their relationship to tumor grade and type. MATERIALS AND METHODS: The preoperative DWI and apparent diffusion coefficient (ADC) characteristics of brain tumors in 41 children were compared with histologic diagnosis. Signal characteristics on DWI and ADC maps correlated well with tumor grade. High-grade lesions were hyperintense on DWI and hypointense on ADC maps. Sensitivity, specificity, positive predictive value, and negative predictive value were 70, 100, 100, and 91%, respectively. Signal characteristics did not differ among different tumors of the same grade. All primitive neuroectodermal tumors showed diffusion restriction whereas none of the ependymomas did. CONCLUSIONS: The signal characteristics on DWI and ADC maps appeared to be strongly correlated to grade in pediatric brain tumors and they may assist with preoperative diagnostic predictions.

Brain Neoplasms↗

Molecular genetics in the diagnosis and prognosis of solid pediatric tumors.

The field of molecular genetics continues to see an ever increasing number of applications to pediatric tumor analysis. Studies in pediatric tumors have identified novel genes and other genetic changes, a large number of which reflect one of the following mechanisms: (1) activation of proto-oncogenes; (2) loss of tumor suppressor genes; or (3) creation of novel fusion proteins. At least one of these mechanisms is operational in each of the following pediatric tumors: neuroblastoma, Ewing sarcoma and peripheral primitive neuroectodermal tumor (pPNET), intra-abdominal desmoplastic small-cell tumor, rhabdomyosarcoma, synovial sarcoma, and Wilms tumor. Out of this research has come not only an increased understanding of oncogenesis but also, for each of the tumors listed above, diagnostic and/or prognostic markers that can be used by the pathologist and oncologist to improve overall patient management.

Child↗

Annulate lamellae in human tumor cells.

Annulate lamellae have been found in a primitive neuroectodermal tumor, a metastatic cerebellar tumor, a testicular seminoma, a retinoblastoma and three melanomas. These annulate lamellae are arranged in stacked parallel arrays in the cytoplasm of tumor cells. The number of annulate lamellae observed to comprise a single stack varies from 2--4 in the seminoma tumor to 5--18 in the cerebellar tumor. Although the functional significance of annulate lamallae is still unknown, in many instances they have been found to be continuous with rough-surfaced cisternae of the endoplasmic reticulum and ribosomes have been demonstrated on the surface of annulate lamellae. This may suggest that annulate lamellae participate in protein synthesis.

Cerebellar Neoplasms↗

Neuroendoscopic anatomy and surgery in pineal region tumors: role of neuroendoscopic procedure in the 'minimally-invasive preferential' management.

The therapeutic modalities for pineal region tumors in Western countries differ from those in far-eastern countries, that is, Japan and Korea, mainly because of the different patient populations. The majority of pineal region tumors in Japan and Korea are radio sensitive and/or chemosensitive, and adjuvant therapy rather than extensive surgery plays the main part in the treatment of these tumors. The authors have applied minimally-invasive preferential management in pineal region tumors in last 8 years. For the therapeutic regimen, if the tumor markers alpha-fetoprotein (AFP) and human chorionic gonadotropin (HCG) were not detected in serum and there was significant ventricular dilation visualized on neuroimages, neuroendoscopic surgery was first applied for tumor debulking with tissue diagnosis and gross morphological analysis of the tumor and the intraventricular structures, followed by third-ventriculostomy. In the results, our minimally-invasive preferential regimen clarified the precise indication for neuroendoscopic procedures, and the majority of our patients with dilated ventricles and no evidence of tumor markers were treated satisfactorily with effective neuroendoscopic procedures as the initial procedure. Then avoided unnecessary craniotomy and radiotherapy and promised excellent therapeutic outcomes. Neuroendoscopic procedures have a great advantage in the management of chemo- or radiosensitive tumors, such as germinoma, pineoblastoma, or primitive neuroectodermal tumor. The neuroendoscopic anatomy including the lateral and third ventricles with a pineal region tumor with or without tumor dissemination was described in detail, together with the neuroendoscopic surgical technique.

Brain Neoplasms↗

The oligodendroglial lineage marker OLIG2 is universally expressed in diffuse gliomas.

Astrocytomas, oligodendrogliomas, and oligoastrocytomas, collectively referred to as diffuse gliomas, are the most common primary brain tumors. These tumors are classified by histologic similarity to differentiated astrocytes and oligodendrocytes, but this approach has major limitations in guiding modern treatment and research. Lineage markers represent a potentially useful adjunct to morphologic classification. The murine bHLH transcription factors Olig1 and Olig2 are expressed in neural progenitors and oligodendroglia and are essential for oligodendrocyte development. High OLIG expression alone has been proposed to distinguish oligodendrogliomas from astrocytomas, so we critically evaluated OLIG2 as a marker by immunohistochemical and oligonucleotide microarray analysis. OLIG2 protein is faithfully restricted to normal oligodendroglia and their progenitors in human brain. Immunohistochemical analysis of 180 primary, metastatic, and non-neural human tumors shows OLIG2 is highly expressed in all diffuse gliomas. Immunohistochemistry and microarray analyses demonstrate higher OLIG2 in anaplastic oligodendrogliomas versus glioblastomas, which are heterogeneous with respect to OLIG2 levels. OLIG2 protein expression is present but inconsistent and generally lower in most other brain tumors and is absent in non-neuroectodermal tumors. Overall, OLIG2 is a useful marker of diffuse gliomas as a class. However, expression heterogeneity of OLIG2 in astrocytomas precludes immunohistochemical classification of individual gliomas by OLIG2 alone.

Animals↗

DNA histogram typing in a series of 707 tumors of the central and peripheral nervous system.

The diagnostic value of ploidy level was investigated in a series of 707 tumors (from 707 patients) of the central and peripheral nervous system. The series contained 91 nerve sheath tumors (NSTs), 222 meningiomas (MNGs), 37 primitive neuroectodermal tumors (PNETs), 293 glial tumors of the adult (ATTs), and 64 brain metastases (MTTs). The ploidy level of each tumor was obtained by means of its DNA histogram type (DHT), which was computed (digital cell image analysis) on Feulgen-stained nuclei from archival formalin-fixed paraffin-embedded materials. The data reveal that the measurement of the ploidy level showed a diagnostic value in some of these tumor cases. Indeed, the proportion of highly aneuploid cases significantly (p < 0.05-0.01) decreased according to the sequence PNETs (72%)-->MTTs (64%)-->ATTs (40%)-->NSTs (23%)-->MNGs (9%). Nevertheless, this significant diagnostic value in terms of a distinction between benignity and malignancy only appears when all the tumors are taken into consideration. Indeed, at the level of one individual patient, our study shows that, like traumatic neuromas, schwannomas, or classical meningiomas, completely benign tumors can exhibit a high aneuploidy level. In contrast, some tumors from histopathological groups like brain metastases or PNETs, which are known to be clinically aggressive, could be completely diploid.

Astrocytoma↗