1/53. comparative genomic hybridization of medulloblastomas and clinical relevance: eleven new cases and a review of the literature.Medulloblastomas are highly malignant primitive neuroectodermal tumors of the cerebellum that display a wide variety of histopathological patterns. However, these patterns do not provide an accurate prediction of clinical-biological behavior and no satisfactory morphological grading system has ever been presented. Genetic alterations may provide additional diagnostic information and allow clinically relevant subgrouping of primitive neuroectodermal tumors. We examined 10 medulloblastomas and one medulloblastoma cell line. One amplification site on chromosome 8q24 was detected in the cell line corresponding to the known amplification of the c-myc gene in this cell line. The gain of 2p21-24 in two tumors was shown to represent amplification of the N-myc gene by Southern blot hybridization and fluorescence in situ hybridization. The data show that the isochromosome 17 can be recognized using comparative genomic hybridization (CGH) by the typical combination of loss of 17p combined with gain of 17q. No specific pattern of genetic alterations could be linked to the clinical behavior of the tumors. We have compared our results with previous CGH studies on medulloblastomas.- - - - - - - - - - ranking = 1keywords = neuroectodermal (Clic here for more details about this article) |
2/53. High-dose anthracyclines in the treatment of advanced primitive neuroectodermal tumors in adults--a single institution experience.Primitive neuroectodermal tumors (PNET) are rare malignancies of presumed neural crest origin, most often presenting as bone or soft tissue masses in the trunk or axial skeleton, in children and young adults. Treatment of advanced PNET in adults is not clearly defined in the literature. Data concerning dose-intensive chemotherapy regimens for poor-risk patients with those tumors are sparse, due to rarity of PNET in adults, their diverse presentation, the variable treatment procedures applied and the absence of direct comparisons. On the other hand, the role of anthracyclines in the treatment of advanced soft tissue sarcomas is well known and substantial. Six advanced PNET patients were treated at the Institute for Oncology and radiology of serbia, during last five years, with high-doses of doxorubicin or epidoxorubicin combined with cisplatin. The paper reviews each of our patients, discussing how does chemotherapy influence the outcome in these patients, in context of the feasibility of high-doses of anthracyclines in advanced settings. High dose anthracyclines (epidoxorubicin 150 mg/m2) in combination with cisplatin 120 mg/m2 induced a complete response lasting for 63 months in a patient with desmoplastic medulloblastoma of the cerebellum metastatic to bones and bone marrow. The same treatment but with the epidoxorubicin dose of 180 mg/m2 induced a complete response in a patient with olfactory neuroblastoma. Administration of high dose doxorubicin (75 mg/m2) seems feasible in association with irradiation treatment in patients with extraosseal Ewing sarcoma/PNET but the place of high dose chemotherapy within this setting remains to be determined.- - - - - - - - - - ranking = 2.5keywords = neuroectodermal (Clic here for more details about this article) |
3/53. Medullomyoblastoma: case report.This 7-year-old boy presented with a 2-week history of headache, nausea, vomiting, anorexia, lethargy, and unsteadiness of gait. brain magnetic resonance imaging (MRI) revealed a cystic mass within the vermis of the cerebellum. A suboccipital craniectomy was performed to remove a tumor that contained primitive neuroectodermal cells with florid skeletal muscle differentiation. Immunohistochemical studies and electron microscopy confirmed the presence of both a primitive neuroectodermal component and rhabdomyoblastic differentiation, consistent with the diagnosis of medullomyoblastoma. This exceedingly rare tumor of the cerebellar vermis of children is characterized by two components: primitive neuroectodermal tumor cells and skeletal muscle. Although the histogenesis remains uncertain, advances in immunohistochemistry and electron microscopy suggest the origin of this tumor from a multipotential stem cell precursor.- - - - - - - - - - ranking = 1.5keywords = neuroectodermal (Clic here for more details about this article) |
4/53. Metastatic infiltration of the dental pulp by medulloblastoma.medulloblastoma is an infratentorial primitive neuroectodermal tumour. It is the most commonly occurring brain tumour of childhood, accounting for 15-20% of all paediatric tumours. Extracranial metastasis is rare, but may involve the skeleton. jaw lesions, however, have never been described. A case is reported of metastases of a medulloblastoma to the jaw including the dental pulp.- - - - - - - - - - ranking = 0.5keywords = neuroectodermal (Clic here for more details about this article) |
5/53. Primary intracranial atypical teratoid/rhabdoid tumor in a child: a case report.Rhabdoid tumors of the central nervous system are rare malignancies. Primary central nervous system atypical teratoid/rhabdoid tumors (ATT/RhTs) mostly occur during early childhood and are almost invariably fatal. These tumors show similar histological and radiological features to primitive neuroectodermal tumormedulloblastoma (PNET-MB) but have different biological behaviors. We report a case of primary intracranial ATT/RhT in the posterior cranial fossa of a child. Preoperative radiological diagnosis was PNET-MB, but pathological diagnosis is ATT/ RhT. The case involved a 16-month-old baby boy who presented with severe headache, vomiting, and gait disturbance. He was treated by surgical resection, chemotherapy, and radiotherapy. Despite aggressive therapy, he died 19 months after diagnosis. Clinical, radiological, and histopathological features of primary intracranial ATT/RhT are discussed with a special emphasis on the differential diagnosis from PNET-MB.- - - - - - - - - - ranking = 0.5keywords = neuroectodermal (Clic here for more details about this article) |
6/53. 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.- - - - - - - - - - ranking = 0.5keywords = neuroectodermal (Clic here for more details about this article) |
7/53. Primitive neuroectodermal tumor arising in long-standing cerebellar atrophy.Primitive neuroectodermal tumors (PNETs) account for one fifth of childhood brain tumors. Although little is known of the pathobiology of this tumor type, there are associations with both genetic syndromes and exposures to specific environmental agents. Progressive cerebellar atrophy predating the presentation of a primary brain tumor, in the absence of a genetic syndrome, has not been reported with PNETs. We report a case of a posterior fossa PNET occurring in association with long-standing cerebellar atrophy without evidence of a genetic syndrome. This case may represent an unrecognized paraneoplastic syndrome or a unique subtype of PNET.- - - - - - - - - - ranking = 2.5keywords = neuroectodermal (Clic here for more details about this article) |
8/53. Primitive neuroectodermal tumor in the cerebellopontine angle with isochromosome 17q presenting as meningioma in a woman 26 years of age.An unusual posterior fossa neoplasm in a 26-year-old woman with short history of the cerebellar symptoms is presented. CT and MR images showed the tumor within the cerebellopontine angle, suspected as meningioma. At surgery, the tumor was dura-attached and did not infiltrate the arachnoid. Histologically, the neoplasm was a small blue cell tumor with solid and microcystic pattern, consistent with primitive neuroectodermal tumor (PNET). Immunohistochemically the cells were strongly positive for NCAM and GFAP. fluorescence in situ hybridization (FISH) was performed with the cosmids G9 and F7 (flanking EWSR1/22q12 region) dna probes and dual-color spectrum-orange LSI HER-2/neu (17q11.2)/spectrum green CEP17 (17p11.1-q11.1) DNA probe. The presence of isochromosome 17q within neoplastic cells was found. The tumor was classified as a medulloblastoma. We demonstrate the utility of a multidisciplinary approach to nervous system tumor diagnosis. The clinical features together with histological, immunohistochemical, and characteristic molecular alteration allowed classification of the presented case.- - - - - - - - - - ranking = 2.5keywords = neuroectodermal (Clic here for more details about this article) |
9/53. 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.- - - - - - - - - - ranking = 0.5keywords = neuroectodermal (Clic here for more details about this article) |
10/53. loss of heterozygosity and p53 polymorphism Pro72Arg in a young patient with medulloblastoma.Differently from conventional primary neuroectodermal tumors (PNETs), molecular features of undifferentiated lesions have been poorly studied. medulloblastoma and PNET neoplasms showed a high incidence of loss of heterozygosity (LOH) on chromosome 17p13, in the region of tumor suppressor gene p53. Recent studies have shown a significant correlation between the presence of p53 Arg72Pro polymorphism and several undifferentiated carcinomas. We performed molecular analysis in an anaplastic tumor of posterior fossa in a patient with a constitutional maternal translocation [46,XX,t(5;19)] and a history of headache, nausea and vomiting. We identified the presence of LOH at 17p13 and Pro72Arg polymorphism in tumor DNA. These molecular findings helped us better characterize this undifferentiated tumor and led to a more aggressive therapy.- - - - - - - - - - ranking = 0.5keywords = neuroectodermal (Clic here for more details about this article) |
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