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Results for “Neuroectodermal Tumors, Primitive”

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PubMed2002

Pleomorphic primitive neuroectodermal tumor with glial and neuronal differentiation: clinical, pathological, cultural, and chromosomal analysis of a case.

This paper examines a case of pleomorphic primitive neuroectodermal tumor (PNET) with glial and neuronal differentiation in a 7-year-old girl who was clinicopathologically reported with immunohistochemical and chromosomal analysis. Clinically, a highly aggressive behavior leading to early recurrence with cerebrospinal fluid seedings was characteristic despite total removal and chemoradiation therapy. Pathologically, severe pleomorphism was noted and large ganglioid cells were predominant. Immunohistochemically, the expression of low-molecular neurofilament was recognized in the surgical specimens and increased in the recurrence. Coexpression of vimentin and neurofilament/GFAP was recognized in the culture. Chromosomal analysis showed near-diploidy, but different karyotype from that PNETs previously reported. These findings suggested that PNETs with pleomorphism and differentiation into both glial and neuronal lineages may show aggressiveness and require more aggressive therapy.

Brain Neoplasms↗
PubMed1995

Very-high-dose short-term chemotherapy for poor-risk peripheral primitive neuroectodermal tumors, including Ewing's sarcoma, in children and young adults.

PURPOSE: To improve the prognosis of patients with poor-risk peripheral primitive neuroectodermal tumors (pPNETs; including peripheral neuroepithelioma and Ewing's sarcoma), while testing the feasibility of intensive use in adolescents and young adults of high-dose cyclophosphamide, doxorubicin, and vincristine (HD-CAV). PATIENTS AND METHODS: This report concerns previously untreated patients with newly diagnosed pPNET deemed poor-risk because of a tumor volume more than 100 cm3 or metastases to bone or bone marrow. The P6 protocol consists of seven courses of chemotherapy. Courses 1, 2, 3, and 6 include 6-hour infusions of cyclophosphamide on days 1 and 2 for a total of 4,200 mg/m2 per course (140 mg/kg per course for patients < 10 years old), plus 72-hour infusions of doxorubicin 75 mg/m2 and vincristine 2.0 mg/m2 beginning on day 1 (HD-CAV). Courses 4, 5, and 7 consist of 1-hour infusions of ifosfamide 1.8 g/m2/d and etoposide (VP-16) 100 mg/m2/d, for 5 days. Granulocyte colony-stimulating factor (G-CSF) and mesna are used. Courses start after neutrophil counts reach 500/microL and platelet counts reach 100,000/uL. Surgical resection follows course 3 and radiotherapy follows completion of all chemotherapy. RESULTS: Among the first 36 consecutive assessable patients (median age, 17 years), HD-CAV achieved excellent histopathologic or clinical responses in 34 patients and partial responses (PRs) in two patients. For 24 patients with locoregional disease, the 2-year event-free survival rate was 77%; adverse events were two locoregional relapses, one distant relapse, and one secondary leukemia. All six patients with metastatic disease limited to lungs achieved a complete response (CR) and did not relapse; one is in remission 36+ months from diagnosis, but the other patients are not assessable in terms of long-term efficacy of the P6 protocol because of short follow-up time (n = 3), additional systemic therapy (bone marrow transplantation), or septic death (autopsy showed no residual pPNET). All six patients with widespread metastases had major responses, including eradication of extensive bone marrow involvement, but distant relapses ensued. Myelosuppression was severe, but most patients received the first three courses of HD-CAV within 6 to 7 weeks. Major nonhematologic toxicities were mucositis and peripheral neuropathy. CONCLUSION: Excellent antitumor efficacy and manageable toxicity support the dose-intensive use of HD-CAV for pPNET in children, as well as in young adults. Consolidation of remissions of pPNET metastatic to bone and bone marrow remains a therapeutic challenge.

Adolescent↗
PubMed1998

Peripheral neuroblastoma and primitive neuroectodermal tumor in Japanese black cattle.

Peripheral neuroblastoma was found in a 1-year-old, male, Japanese black cattle (Case 1) and primitive neuroectodermal tumor was noted in 7-year-old, female, Japanese black cattle (Case 2). In Case 1, neoplastic tissue was replaced the right cranial vault and nasopharynx. A large, soft mass approximately 18 cm in diameter was also observed in the right mandibulopharyngeal area. In Case 2, a neoplastic mass of about 15 cm in diameter was found in the mandibulopharyngeal area. Histopathologically, massive necrosis showing a pseudopalisade arrangement was frequently observed in Case 1. On the contrary, Homer & Wright rosette formations of tumor cells were prominent in Case 2. Immunohistochemically, the proliferating cells in Case 1 were positive for vimentin, S-100, and neurofilament (NF) and those in Case 2 showed intense immunoreactivity for NF and neuron specific enolase, but were negative for vimentin and S-100. The different degrees of differentiation of the neoplastic cells originating from the neuroectoderm, might be reflected in their different morphological and immunohistochemical features.

Animals↗
PubMed2005

Patterns of treatment failure in infants with primitive neuroectodermal tumors who were treated on CCG-921: a phase III combined modality study.

PURPOSE: To analyze patterns of treatment failure in infants with primitive neuroectodermal tumors (PNETs) who were treated primarily with chemotherapy in a large multi-institutional study. MATERIALS AND METHODS: Sixty-five prospectively staged patients with PNET confirmed by central pathology review, who were 18 months or younger were treated on Children's Cancer Group Study 921 (CCG-921) primarily with chemotherapy. Forty-six patients had posterior fossa (PF) primary tumors and 19 patients had supratentorial (ST) primaries. Patterns of sites of initial treatment failure were analyzed and compared to failure patterns of 180 older children who had PF-PNETs, and 44 older children with ST-PNETs who were treated on the same protocol. RESULTS: The entire cohort of younger patients fared much worse than those older than 18 months. Cumulative 5-year relapse incidence (+/-SE) for younger patients with PF-PNETs was 64.5 +/- 8.9% for patients without metastases (M0) compared to 71.4 +/- 13.4% for patients with metastases (M+). The cumulative 5-year relapse incidences for younger patients with ST-PNETs were 64.3 +/- 13.7% for M0 patients compared to 100 +/- 33.3% for M+ patients. Relapses in these patients occurred within 2 years. The overall treatment failure rate was significantly higher for younger compared to older patients with PF-PNET and ST-PNET. There was no statistically significant difference in relapse patterns between patients with PF primary tumors and ST primaries when stratified by stage. There was no statistically significant difference in relapse patterns between M0 and M+ patients. All patients had a high risk of recurrence at primary tumor site. Younger patients who had PF primary tumors without metastasis at presentation were significantly more likely to relapse in PF than older patients. Younger patients were at significant risk of relapse in the spine, but none had it as the sole site of first relapse. CONCLUSIONS: Despite aggressive chemotherapy, younger children with PNETs have high rates of treatment failure and fare worse than high-risk, older patients with PF-PNETs, indicating the need to maximize local, regional, and systemic therapies.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed2002

Primary primitive neuroectodermal tumor of the spinal cord: case report and review of the literature.

We present the clinical, radiological, and pathological features of a primary primitive neuroectodermal tumor (PNET) that occurred in the thoracic spinal cord of a 69-year-old man. Magnetic resonance imaging (MRI) demonstrated on T1-weighted images a 2x1x5 cm isointense intraspinal mass with homogeneous contrast enhancement extending from the C7 to the Th3 level. There was no clinical or radiological evidence for the existence of an intracranial tumor. Histological examination revealed a small round cell tumor with rosette formation and immunohistochemical characteristics of a PNET. The patient is the oldest among the 20 cases with this rare spinal cord neoplasm reported so far in the literature; the previously published cases are briefly reviewed.

Age of Onset↗
PubMed2006

Coexistence of peripheral primitive neuroectodermal tumor and tetralogy of Fallot.

We describe a little girl with tetralogy of Fallot (TOF) who was found to have a huge peripheral primitive neuroectodermal tumor (pPNET) when she developed progressive difficulty in standing and crawling at the age of 11 months. The tumor was located in the left paraspinal region (T4-T12), with intraspinal extension causing severe compression. Nine days after surgical decompression with laminectomy, chemotherapy was initiated with alternative courses of vincristine, doxorubicin, cyclophosphamide, etoposide, and ifosfamide every 3 weeks. The muscle power in her legs recovered substantially after 2 courses of chemotherapy. Although peripheral blood for cytogenetic study revealed no chromosome abnormality, recent cytogenetic analysis has revealed a high frequency of reciprocal translocation t(11;22)(q24;q12) detected in pPNET and a strong association between TOF and chromosome 22q11 microdeletion (del 22q11). Both genetic defects involve chromosome 22q in the close region. This case report illustrates the necessity of investigating for cytogenetic change in chromosome 22 and close follow-up due to the possibility of subsequent development of malignancies in patients with TOF.

Chromosome Aberrations↗
PubMed1998

Molecular analysis of childhood primitive neuroectodermal tumors defines markers associated with poor outcome.

PURPOSE: The diagnostic and prognostic significance of well-defined molecular markers was investigated in childhood primitive neuroectodermal tumors (PNET). MATERIALS AND METHODS: Using microsatellite analysis, Southern blot analysis, and fluorescence in situ hybridization (FISH), 30 primary tumors and six CSF metastasis specimens were analyzed for loss of heterozygosity (LOH) of chromosomes 1q31, 6q, 9q22, 10q, 11, 16q22, and 17p13.1 and/or high-level amplification of the c-myc gene. Experimental data were compared with clinical stage and outcome. RESULTS: LOH of chromosome 17p13.1 was found most frequently (14 of 30 tumors, six of six CSF metastasis specimens); LOH of chromosomes 10q, 16q22, 11, 6, 9q22, and 1q31 was observed in 20.6%, 20%, 14.3%, 12%, 10%, and 0%, respectively. Eight of 32 tumors and CSF specimens showed amplification of c-myc. All tumors with amplification of c-myc were resistant to therapy and had a fatal outcome (mean survival time, 9.3 months). Tumors that displayed LOH of chromosome 17p were associated with metastatic disease. The prognosis of these tumors was worse only when associated with amplification of c-myc. Three of three patients with LOH of 9q22 relapsed. CONCLUSION: In our study, amplification of c-myc was a poor-prognosis marker in PNET. LOH of chromosome 17p was associated with metastatic disease. Molecular analysis of primary tumors using these markers may be useful for stratification of children with PNET in future prospective studies. The other aberrations investigated were not of significant prognostic value, but may provide an entry point for future large-scale molecular studies.

Adolescent↗
PubMed1998

Missense mutations in SMOH in sporadic basal cell carcinomas of the skin and primitive neuroectodermal tumors of the central nervous system.

About one-third of sporadic basal cell carcinomas (BCCs) of the skin and 10-15% of primitive neuroectodermal tumors (PNETs) of the central nervous system show mutations in the PTCH tumor suppressor gene. The PTCH gene product (Ptch) functions as a transmembrane receptor for the Sonic hedgehog protein (Shh) and interacts with another transmembrane protein called Smoh. To further elucidate the significance of alterations in the Shh signaling pathway, we investigated 31 sporadic BCCs and 15 PNETs for the mutation and/or expression of SMOH, PTCH, SHH, and GL11. In addition, we fine-mapped the SMOH gene locus by fluorescence in situ hybridization to chromosomal band 7q32. Mutational analysis identified four BCCs with somatic missense mutations in SMOH affecting codon 535 (TGG==>TTG: Trp==>Leu) in three tumors and codon 199 (CGG==>TGG: Arg==>Trp) in one tumor. A missense mutation at codon 533 (AGC==>AAC: Ser==>Asn) was found in one PNET. PTCH mutations were detected in eight BCCs and one PNET. Two BCCs demonstrated mutations in both SMOH and PTCH. The majority of tumors showed an increased expression of SMOH, PTCH, and GL11 transcripts as compared with that of normal skin and nonneoplastic brain tissue, respectively. In contrast, only one BCC and one PNET expressed SHH mRNA at levels detectable by reverse transcription-PCR, and no SHH gene mutations were found. In summary, our results indicate that both PTCH and SMOH represent important targets for genetic alterations in sporadic BCCs and PNETs.

Adolescent↗
PubMed1997

Prognostic significance of chromosome 17p deletions in childhood primitive neuroectodermal tumors (medulloblastomas) of the central nervous system.

Deletions in the short arm of chromosome 17 (17p) are the most common genetic abnormality in primitive neuroectodermal tumors of the posterior fossa/medulloblastoma (PNET/Mb). The biological consequences of these deletions are not known for children with PNET/Mb; however, the presence of a tumor suppressor gene located in 17p, distinct from p53, has been implicated in tumorigenesis. Two recent studies suggest that 17p deletions in PNET/Mb are associated with a poor prognosis. To address this question, we identified deletions of chromosome 17p by cytogenetic and/or molecular biology methods in tumor biopsy samples from 56 patients with PNET/Mb. Associations between clinical characteristics or survival outcomes and 17p status were examined by multivariate analysis. Forty-one percent of PNET/Mb cases had a deletion of 17p. No significant association was found between 17p deletion and shorter survival duration or higher metastatic stage. Multivariate analysis did not find independent prognostic significance for 17p deletions after accounting for the effects of significant clinical variables. A larger study of the prognostic value of 17p deletion should be considered; however, clinical use of this factor to distinguish high-risk from standard-risk PNET/Mb populations is not warranted at this time.

Age Factors↗
PubMed1995

EWS-FLI-1 and EWS-ERG chimeric mRNAs in Ewing's sarcoma and primitive neuroectodermal tumor.

The t(11;22)(q24;q12) and t(21;22)(q22;q12) are specific chromosomal translocations found in the Ewing family of tumors including ES, PNET and Askin tumors. In these translocations, the amino-terminal portion of the EWS gene located in 22q12 fuses to the carboxyl-terminal portion of the FLI-1 gene located in 11q24 or the ERG gene located in 21q22, which belong to the ets oncogene superfamily of transcription activators. We investigated the chimeric mRNAs of 15 ESs (7 cell lines and 8 tumor samples) and 7 PNETs (3 cell lines and 4 tumor samples) using the RT-PCR method and sequencing. We detected 2 types of EWS-ERG chimeric mRNA in 2 ES cell lines and 1 PNET tumor sample in addition to 4 types of EWS-FLI-1 chimeric mRNA in 11 ESs (4 cell lines and 7 tumor samples) and 4 PNETs (2 cell lines and 2 tumor samples). There seemed to be no association between the type of chimeric mRNA and clinical features such as sex, age, primary site and histopathology of the patients. All of the chimeric mRNAs are generated from in-frame junctions and are thought to encode fusion proteins that may be the molecular mechanism involved in the Ewing family of tumors.

Adolescent↗
PubMed1996

Chemotherapy for medulloblastomas and primitive neuroectodermal tumors.

In the past two decades, chemotherapy has proven to be an increasingly more effective modality in the treatment of medulloblastoma. Current evidence suggests that chemotherapy be included as part of standard treatment for all patients with high-risk medulloblastoma. Ongoing multi-centre trials are determining whether chemotherapy should be added to reduced dose radiotherapy as a substitute therapy for standard-dose radiotherapy. The major randomized and non-randomized chemotherapy trials for newly diagnosed patients with medulloblastoma or for patients at recurrence are presented. It is hoped that the addition of chemotherapy will eventually lead to improved survival rates as well as the reduction in the craniospinal radiotherapy dose for patients with medulloblastoma.

Brain Neoplasms↗