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PubMed2001

Abundance of apoptotic neoplastic cells in diagnostic biopsy samples is not a prognostic factor in childhood primitive neuroectodermal tumors of the central nervous system.

PURPOSE: To assess if the abundance of apoptotic tumor cells is an independent prognostic factor in primitive neuroectodermal tumors (PNET) of the central nervous system. PATIENTS AND METHODS: Formalin-fixed paraffin-embedded tumor tissue sections from 78 clinically well-characterized children with PNET were evaluated by terminal deoxytransferase-mediated deoxyuridinie-5'-triphosphate (dUTP) nick-end labeling (TUNEL). Apoptotic indices (AI) were determined by counting TUNEL-positive tumor cells either in the highest staining region (AI hot spot) or in at least 15 randomly chosen fields (AI random). The AI hot spot and AI random were then correlated with clinical variables and survival outcome. RESULTS: AI hot spot (median 0.56%; range 0%-6.54%) and AI random (median 0.30%; range 0%-3.21%) showed considerable intertumor variability. Moreover, 53% of the evaluated PNET showed a more than two-fold difference between AI hot spot and AI random, showing important intratumoral variability of the abundance of apoptotic cells in a subset of the evaluated PNET. No significant associations were found between AI hot spot and AI random with clinical variables or survival outcome. CONCLUSION: The apoptotic index does not predict survival outcome and is not specifically associated with clinical variables of prognostic significance in childhood PNET.

Apoptosis↗
PubMed2002

Primary intraspinal primitive neuroectodermal tumor: case report of a tumor arising from the sacral spinal nerve root and review of the literature.

Primary spinal primitive neuroectodermal tumor (PNET) is a rare condition, 18 cases of which have been reported in the literature. In general, this tumor is treated with surgery followed by radiotherapy and chemotherapy, but prognosis is still poor. An 18-year-old female patient with an intradural, extramedullary mass at L3-L5 levels is presented in this report. This is the first female patient with primary spinal PNET at lumbar region, second patient with spinal nerve root origin, and third one with intradural, extramedullary localization ever reported in the literature. After surgery, she was treated with craniospinal radiotherapy and four cycles of combination chemotherapy regimen consisting of vincristine, cyclophosphamide, doxorubicin alternated with ifosfamide, and VP-16. Currently, she is asymptomatic and alive at 25 months. The histopathologic, radiologic, and clinical findings of the patient are presented and relevant literature is reviewed.

Adolescent↗
PubMed1991

Loss of heterozygosity on 6q, 16q, and 17p in human central nervous system primitive neuroectodermal tumors.

The loss of genetic material from specific chromosomal locations in a given tumor type has been taken for evidence of the importance of tumor suppressor genes at these loci in the genesis of the tumor. The primitive neuroectodermal tumor of the central nervous system has such a loss on 17p in one-third of tumors. In this report, a detailed analysis of 17p loss in 23 tumors has been performed using 10 probes mapping to this region. In addition, an analysis for allelic deletion on chromosomes 6q, 16q, and 22q has been performed. Six of the 23 tumors showed loss of markers on 17p, and the area of common loss spanned 17p11.2 to 17pter. Five of 23 tumors showed loss of markers on 6q, and 3 showed loss on 16q. No tumor lost markers on 22q. Only one tumor showed loss at more than one location. These data suggest that primitive neuroectodermal tumors either are a heterogeneous group of tumors with more than one mechanism leading to a tumor or that more than one recessive oncogene may play a role in the genesis of these tumors.

Adult↗
PubMed1999

A cerebral primitive neuroectodermal tumor in a squirrel monkey (Saimiri sciureus).

An adult squirrel monkey with a history of long-term exposure to microwave radiation was found at necropsy to have a malignant tumor of the right cerebral cortex. Gross examination revealed a mass with expanding borders in the right frontoparietal cortex with compression of the adjacent lateral ventricle. Microscopy revealed a tumor composed of sheets of moderate-sized cells, resembling an oligodendroglioma, with clear cytoplasm and central nuclei interrupted by delicate vasculature. Malignant features were present in the form of marked nuclear pleomorphism, frequent mitotic figures, and focal necrosis. A neuronal cell origin for this tumor was supported by immunohistochemical analysis, which revealed immunopositivity for neurofilament proteins and neuron-specific enolase. Staining for vimentin and glial fibrillary acid protein was negative, except in reactive astrocytes at the tumor margins and adjacent to intra-tumoral blood vessels. Antibody activity against Ki-67 antigen, a marker of rapidly proliferating tumor cells, and p53 oncoprotein was strongly positive, indicative of the aggressive and malignant nature of this tumor. The tumor was diagnosed as a cerebral primitive neuroectodermal tumor.

Animals↗
PubMed2002

Malignant peripheral primitive neuroectodermal tumor of the kidney.

Ewing family of tumors is a group of highly aggressive neoplasias that occur most commonly in the first two decades of life. These tumors are most frequently localized in bones, less frequently in soft tissues. They usually appear as undifferentiated small round-cell tumors. With current treatment regiments, 5-year disease-free survival rates exceed 60% in patients with a localized disease. Patients with metastatic disease at the time of their first presentation have a poor prognosis. We describe a rare case of visceral primitive neuroectodermal tumor with the involvement of the kidney in a 9-year-old girl. The tumor was studied with immunohistochemistry, cytogenetics, and molecular biology methods. Strong expression of protein MIC(2) by immunochemistry (antibody HBA 71) with subsequent demonstration of a translocation consistent with t(11;22)(q24;q12) using cytogenetic and reverse transcriptase polymerase chain reaction (RT-PCR) confirmed the histopathological diagnosis of peripheral primitive neuroectodermal tumor. We detected minimal residual disease in bone marrow using RT-PCR.

Bone Marrow Cells↗
PubMed1994

Primitive neuroectodermal tumor arising in the pancreas.

Peripheral primitive neuroectodermal tumors (PNETs) are extra cranial primitive small round blue cell tumors showing histologic, immunohistochemical or electron microscopic evidence of neuroectodermal differentiation. They are most commonly encountered in the soft tissue or bone in children and young adults. We report an unusual case of a PNET arising in the pancreas. A 17-yr-old male presented with a pancreatic mass and underwent a pancreatoduodenectomy. Histologically, the neoplasm was composed of sheets of small round cells that stained for cytokeratin, neuron specific enolase, and 12E7 but not muscle specific action, desmin, common leukocyte antigen, chromogranin, synaptophysin, or other islet cell markers. The diagnosis of PNET in this unusual location was confirmed by cytogenetic analysis which showed the chromosomal translocation characteristics of PNETs, t(11;12)(q24;q12). This case highlights the difficulty in the diagnosis of PNET when it is present in visceral organs where other neuroendocrine neoplasms and adenocarcinomas are more common.

Adolescent↗
PubMed1998

Interleukin-1 alpha (IL-1 alpha), IL-1 beta, IL-1 receptor type I, IL-1 receptor antagonist, and TGF-beta 1 mRNAs in pediatric astrocytomas, ependymomas, and primitive neuroectodermal tumors.

Interleukin-1 alpha (IL-1 alpha), IL-1 beta, interleukin-1 receptor type I (IL-1RI, signaling receptor), and IL-1 receptor antagonist (IL-1Ra, endogenous inhibitor) are pivotal components of the IL-1 system. IL-1 and other cytokines induced by IL-1, such as TGF-beta 1, may participate in the growth of various tumor cells. In children, primary nervous system tumors represent the most common solid malignancy. We investigated the levels of IL-1 alpha, IL-1 beta, IL-1RI, IL-1Ra, and TGF-beta 1 mRNAs in pediatric astrocytomas (n = 19), ependymomas (n = 13), and primitive neuroectodermal tumors (n = 22) using sensitive and specific RNase protection assays. The data show a significant distinct cytokine mRNA profile among brain tumor types. Pilocytic, nonpilocytic, and anaplastic astrocytomas have significant increased levels of IL-1 beta, IL-1RI, and TGF-beta 1 mRNAs, but low levels of IL-1Ra mRNA; this may have implications for an IL-1 beta feedback system and IL-1 beta<-->TGF-beta 1 interactions in astrocytomas. Ependymomas show increased levels of IL-1 alpha and IL-1 beta mRNAs associated with low levels of IL-1Ra mRNA; primitive neuroectodermal tumors do not exhibit increased levels of any cytokine component examined. The data also suggest that a dysregulation of the balance between stimulatory and inhibitory cytokines may be involved in the growth and development of brain tumors via autocrine/paracrine mechanisms.

Adolescent↗
PubMedDate not supplied

Prenatal imaging of congenital cerebral primitive neuroectodermal tumor.

A case of fetal brain tumor, which appeared after 32 weeks' gestation, is presented. Prenatal ultrasonography and magnetic resonance imaging demonstrated a large heterogeneous mass in the right supratentorial region and left enlarged ventricle. A male fetus weighing 2,616 g was delivered at 34 weeks' gestation by cesarean section and died on the 37th day of life due to rapid growth of the tumor. Following autopsy, the pathohistological examination revealed primitive neuroectodermal tumor. Magnetic resonance imaging in the prenatal management of the congenital brain tumor is efficient in evaluating the expansion and margin of the tumor and intratumoral bleeding, which are not demonstrated by ultrasonography.

Adult↗
PubMed2002

Atypical pleomorphic extraosseous ewing tumor/peripheral primitive neuroectodermal tumor with unusual phenotypic/genotypic profile.

A pleomorphic undifferentiated tumor primarily located in the retroperitoneum with a phenotype compatible with an extraosseous Ewing tumor/peripheral primitive neuroectodermal tumor (ET/pPNET) pattern and unusual molecular features is described. Immunohistochemically, HBA-71 (CD99/mic2) and several neural markers were intensively expressed together with scattered cells expressing carcinoembryonic antigen (CEA). Short-term culture showed biphasic neuroblastic and epithelioid cell populations, with the latter expressing germ cell markers (CEA, alpha-fetoprotein, and the beta-subunit of chorionic gonadotrophin). Conventional cytogenetics displayed several chromosomic rearrangements, especially a complex translocation t(17,2,22,13) (q21::q11-->q33::q12-->q13::q14). These structural abnormalities were confirmed using fluorescence in situ hybridization analysis. Molecular studies revealed EWS-FEV fusion transcripts (exon 7 of the EWS gene and exon 2 of the FEV gene). In addition, a new p53 mutation not previously reported in ET/pPNET involving exon 5 codon 138: GCC to GAC (Ala/Asp) was detected. In our case, we emphasize the presence of atypical features not only from the phenotypic point of view but also at the genetic level as well as the value of detecting such markers in the differential diagnosis with other abdominal pleomorphic tumors.

Adult↗
PubMed1990

Human monoclonal antibodies to neuroendocrine granules derived from tumor-infiltrating lymphocytes isolated from a primitive neuroectodermal tumor.

Tumor-infiltrating lymphocytes were isolated from a primitive neuroectodermal tumor and fused with GM4672 cells, resulting in hybrids secreting human IgM-kappa antibody, which is reactive to olfactory neuroblastoma tumor cells. Hybridoma clones 4F and 9G produce human monoclonal antibodies reactive to autologous and allogeneic neuroblastoma tumor cells and subsets of pancreatic islet cells in formalin-fixed tissues. They react specifically with dense core granules of glucagon and insulin-producing islet cells, but not with those in cells producing somatostatin. Calcitonin granules are not recognized by these antibodies. The area of localization of the granules is distinct from the component labeled by murine monoclonal antibodies to chromogranin A. The clones have remained stable in culture for over two years and continue to secrete up to 60 micrograms/mL of human IgM. This study demonstrates the possibility of directly analyzing the antibody repertoire of tumor-infiltrating B cells, and this technique may allow the development of human monoclonal antibodies to other novel cellular antigens.

Antibodies, Monoclonal↗
PubMed1994

Characterization of five new cell lines derived from human primitive neuroectodermal tumors of the central nervous system.

Medulloblastoma (MB) represents the most frequent malignant brain tumor of childhood but only a few cell lines and animal models of this primitive neuroectodermal tumor (PNET) have thus far been established. Using specific cell culture conditions, we were able to derive four human MB cell lines (MHH-MED-1-4) as well as a cell line from a spinal PNET (MHH-PNET-5). The four MB cell lines grew in suspension as floating cell aggregates or as slightly adherent cells. They consisted of undifferentiated cells that did not express markers of late neuronal or glial lineages such as neurofilaments or glial fibrillary acidic protein. They also lacked expression of major histocompatibility complex class I or II antigens on the cell surface. All four MB lines were positive for vimentin and neuron-specific enolase, whereas synaptophysin, neural cell adhesion molecule, galactocerebroside, GD2, GD3, and the A2B5 antigen were expressed inconsistently. In contrast, MHH-PNET-5 grew as adherent monolayer and expressed major histocompatibility complex class I antigen. By cytogenetic analysis, the lines were near diploid with clonal aberrations. The MB lines showed no losses of chromosome arm 17p by either cytogenetic or microsatellite analyses. The cell line MHH-MED-2 exhibited double minute chromosomes, amplification of the c-myc gene, and overexpression of c-myc mRNA and protein. N-myc, p53, and Rb protein expression were unaltered. All four continuously passaged MB cell lines and the MHH-PNET-5 line were xenotransplanted s.c. into athymic mice; three of four MB lines and the spinal PNET line gave rise to tumors. These cell lines will be useful tools for biological and preclinical studies on PNETs.

Animals↗
PubMed2002

[Primitive neuroectodermal tumor of the cauda equina. Report of a case].

Primitive neuroectodermal tumors are malignant neoplasms whose classification has been controversial. Spinal primitive neuroectodermal tumors are rare and at the cauda equina are even less common. We report the case of a 40 year-old man with a history of progressive back pain and gait difficulty. After the diagnosis of a primitive neuroectodermal tumor of the cauda equina, the patient presented seeding to the intracranial subarachnoid space followed by a poor outcome. We review the literature of primary spinal primitive neuroectodermal tumors.

Adult↗
PubMed1991

[Primitive neuroectodermal tumor with Wilms' tumor. Case report].

Occurrence of embryonal kidney tumors in patients with primitive neuroectodermal tumors, so-called central nervous system-renal neoplasia has been reported. An infant who presented with masses in the right lateral ventricle and the cerebellar vermis is reported. Histological examination showed primitive neuroectodermal tumors. Further investigation revealed tumors in the bilateral kidneys, which were removed subtotally and pathologically shown to be Wilms' tumors. The patient was then treated with anticancer drugs and irradiation. However, he developed lung metastases from the renal tumors and expired. At autopsy, a small tumor was found in the inferior horn of the left lateral ventricle. Histological finding showed a primitive neuroectodermal tumor. Also, bilateral large masses of recurrent Wilms' tumors, multiple metastases to the lungs and peritoneal dissemination were found. There is no evidence that this association is based on the selective neoplastic transformation of embryonal cells of similar histogenetic or cytogenetic origin. Several reports demonstrate the presence of embryonal cells in the nervous tissue which could imply a neuroepithelial origin for Wilms' tumors.

Brain Neoplasms↗
PubMed1982

Congenital primitive neuroectodermal tumor (neuroepithelioma) of the chest wall.

Primitive neuroectodermal tumor (neuroepithelioma) is a relatively common central nervous system tumor in children. Those arising from a peripheral nerve are extremely rare in childhood. There is only one reported case in 6-year-old where the tumor arose from the sciatic nerve. A case of neuroectodermal tumor of the chest wall, arising from the intercostal nerve, in a newborn is presented. The tumor metastasized to the brain. Prominent Homer-Wright rosettes, with central eosinophilic fibrillar substance similar to that seen in neuroepithelioma of the central nervous system, were present in the primary tumor and brain metastases. Ultrastructure, as revealed by transmission electron microscopy, is also described.

Brain Neoplasms↗
PubMed2001

Peripheral primitive neuroectodermal tumor: challenge for multimodal treatment.

The primitive neuroectodermal tumor (PNET) is an extremely aggressive soft tissue neoplasm that occurs in children and adolescents. We retrospectively reviewed our therapeutic experience with a multidisciplinary approach, combining surgery, chemotherapy, and radiation therapy. Treatment of PNET was carried out in compliance with the soft tissue protocol (CWS) from the German Society of Pediatric Oncology. Biopsy-proven diagnosis was followed by chemotherapy, which in all cases led to partial remission, allowing excision of the remainder of the tumor without mutilation. After excision, irradiation of the tumor site and two further sequences of chemotherapy were performed. When PNET of the paravertebral region caused symptoms of paralysis and immediate surgery was required, postoperative chemotherapy, a second-look operation, and irradiation were undertaken. Between 1986 and 1998 we treated 13 patients (median age 15 years). In five patients the PNET originated from the chest wall and in eight patients from the paravertebral and retroperitoneal region. Five patients died after 20 months on average, and the remaining eight patients are in full remission after 7, 16, 46, 55, 70, 74, 75, and 115 months, respectively. Close cooperation between surgeons and their pediatric and radiotherapy colleagues is obligatory when treating PNET. Chemotherapy as the first stage is mandatory to avoid a mutilating surgical procedure and intraoperative tumor cell dissemination.

Adolescent↗
PubMed2000

Thoracoabdominal peripheral primitive neuroectodermal tumors in childhood: radiological features.

Peripheral primitive neuroectodermal tumors (PNET) are extremely uncommon, malignant neoplasms affecting mostly children and young adults. We retrospectively reviewed the clinical data and radiological studies of four such cases. All cases were pathologically proven. Plain films, US, and CT scans were used. The youngest child had a huge pelvic tumor and two adolescents each had a chest wall (Askin) tumor. The fourth patient had a most unusual location of the PNET in the anterior mediastinum. The CT findings are emphasized. We emphasize that the markedly abnormal CT findings are not specific for PNET.

Abdominal Neoplasms↗
PubMedDate not supplied

Molecular genetic analysis of a small bowel primitive neuroectodermal tumor.

We present a pediatric peripheral primitive neuroectodermal tumor (pPNET) localized exclusively to the small bowel. The tumor presented in an adolescent male and the diagnosis was confirmed by electron microscopy, CD99 immunopositivity, and molecular genetic analysis that demonstrated an EWS-FLI1 type 2 fusion transcript. This case report and a review of the literature underscore the considerable phenotypic overlap in EWS-related tumors in this site and the necessity for molecular genetic analysis to permit accurate classification.

Adolescent↗