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PubMed1996

Cellular and molecular pathology of medulloblastoma.

Medulloblastoma is a malignant embryonal tumor predominantly of childhood. It occurs principally in the midline cerebellar region but is prone to invade the meninges and cerebrospinal fluid spaces. It is the principal posterior fossa tumor in children and represents 20% of all brain tumors in this age group. Considerable advances have been made in characterizing the morphologic subtypes, immunophenotypes, and in vitro behavior of cell lines. However, the cell of origin and its relationship to other related primitive neuroectodermal tumors remains uncertain. Although recent advances in the application of proliferation markers and the use of apoptosis in situ labelling have been applied, a prognostically relevant marker applicable to surgical neuropathology remains to be developed. The fundamental molecular pathogenesis of tumor development remains unknown, although recent exciting advances have shown alterations in some members of the PAX family of genes as well as increased expression of neurotrophin receptors. These may prove to be of prognostic significance.

Adult↗
PubMedDate not supplied

Fine needle aspiration biopsy of a small round cell tumor exhibiting both neural and myogenic differentiation. A case report.

BACKGROUND: Divergent differentiation may not be detected in the limited material available in a fine needle aspiration biopsy (FNAB). CASE: A small round cell malignancy showed neural features ultrastructurally on FNAB, in keeping with primitive neuroectodermal tumor, but desmin and actin positivity on surgical biopsy, suggesting rhabdomyosarcoma. CONCLUSION: Accurate classification of small round cell tumors by FNAB is more likely to occur when both electron microscopy and immunocytochemistry are employed since these tumors may express divergent differentiation.

Adult↗
PubMed2005

Keratin-positive Ewing's sarcoma: an ultrastructural study of 12 cases.

Ewing's sarcoma/primitive neuroectodermal tumor (EWS/PNET) is an aggressive neoplasm of bone and soft tissue. Histologically, it is characterized by the presence of small round blue cells, which usually express MIC-2 and FLI-1 immunohistochemically. The most specific feature for diagnosis, however, is cytogenetic or molecular evidence of a consistent abnormality, the t(11;22)(q24;q12), or variants thereof. The immunohistochemical expression of keratins in a significant proportion of these cases has been highlighted in several recent studies. The ultrastructural features of these keratin-positive tumors have not, however, been characterized in detail. In this study we analyzed the ultrastructural features of 12 well-documented EWS/PNETs that stained strongly for pankeratin by immunohistochemistry. Ultrastructurally, the tumor cells contained a few organelles, which included a small number of mitochondria, poorly developed Golgi complexes, free ribosomes, and inconspicuous rough-endoplasmic reticulum. Rudimentary cell junctions were seen in 2 tumors while prominent junctions were observed in the remaining 10. Five tumors contained intracytoplasmic filaments, and definite tonofibrils were identified in 2. Well-developed basal lamina around tumor cells were also demonstrated in 2 tumors. Follow-up information was available for all cases. Seven patients died of disease, 2 are alive with disease, and 3 have no current evidence of disease. The cohort includes 5 patients with a type-1 translocation, which has been associated with a better prognosis in some studies; 4 of these patients have died of their disease, and 1 is alive with recurrent disease. This study shows that keratin-positive EWS/PNETs have evidence of epithelial differentiation ultrastructurally, and may possibly represent a more aggressive subset of the EWS/PNET group of tumors.

Adolescent↗
PubMed2004

Radiotherapy for pediatric central nervous system tumors: a regional cancer centre experience.

INTRODUCTION: The purpose of this review was to analyze outcomes for pediatric patients treated for more common (non-low grade glioma) primary central nervous system (CNS) tumors at a Regional (tertiary) Cancer Center. Comparison to reported results from other regional centres and results from the contemporary literature were made. MATERIAL AND METHODS: The records of pediatric patients treated with radiotherapy at the London Regional Cancer Center (LRCC) for more common (non-low grade glioma) primary CNS tumors between 1980 and 2001 were reviewed. Details regarding tumor presentation, treatment and outcome were analyzed. RESULTS: Eighty-eight patients were eligible for the review. Twenty-nine patients with malignant glioma, 37 patients with medulloblastoma or primitive neuroectodermal tumor (PNET), 15 patients with brainstem glioma, 4 with ependymoma and 3 with germ cell tumors were treated during this time period. Average follow-up for the group was 5 years (range 4 months to 19 years). Five-year overall, progression free and cause specific survival were 45, 42 and 50%, respectively. For patients with malignant glioma median progression free and overall survival was 20 and 29 months. For patients with brainstem glioma median progression free and overall survival was 9 and 13 months. For medulloblastoma, 5-year progression free, and overall survival was 60 and 59%. CONCLUSIONS: RESULTS of this retrospective review of pediatric patients treated at a regional cancer center for primary CNS tumors (other than low grade glioma) were comparable to contemporary results reported by other Canadian centers and North American co-operative group trials.

Adolescent↗
PubMed1989

Five novel cell surface antigens of CNS neoplasms.

Optimal monoclonal antibody-mediated immunotherapy requires the identification of tumor-restricted cell surface antigens. We have identified and partially characterized 5 new monoclonal antibodies generated against malignant astrocytoma, medulloblastoma, neuroblastoma and melanoma which were used to define 5 neuroectodermal tumor antigenic systems. CNT/1 identifies a 57-kDa, heat-stable, trypsin-sensitive neuroblastoma surface antigen, which is expressed intracellularly in many malignant gliomas, medulloblastomas, ependymomas, breast and ovarian carcinomas. CNT/2 reacts with a 130-kDa, heat-labile, trypsin- and neuraminidase-resistant antigen restricted to low-grade astrocytomas and malignant gliomas. CNT/11 reacts with a 70-kDa, heat-labile, trypsin-sensitive antigen coded for by a gene on chromosome 12, and is restricted to astrocytomas, neuroblastomas and sarcomas. CNT/8 identifies a heat-labile, trypsin-sensitive antigen whose gene has been localized to chromosome 15 and is expressed by neuroectodermal and mesodermally derived tumors and few epithelial cancers. The B2.6 antigen is identified only in terms of serologic reactivity with a subset of cultured astrocytomas and melanomas. Neuroectodermal tumor-associated antigens may be categorized as lineage-consistent, lineage-independent and putatively tumor-restricted in their expression. These restricted antibodies may be potentially useful reagents to consider for monoclonal antibody-mediated immunotherapy of CNS neoplasms.

Antibodies, Monoclonal↗
PubMed1993

Intraarterial cisplatinum and intravenous adriamycin for primary hypervascular bone tumor: experience of seven cases.

Seven consecutive cases of primary hypervascular bone tumor, encountered between January 1991 and September 1992, were treated with intraarterial cisplatinum and intravenous adriamycin infusion. There were four osteosarcomas, one malignant fibrous histiocytoma, one chondrosarcoma and one case of primitive neuroectodermal tumor. Local symptoms were markedly relieved, or disappeared, in 71% (5/7) of cases after the first course of treatment. Sclerotic changes of bone tumor occurred in 100% (6/6) of cases after two courses of chemotherapy. Progressive decrease of tumor stains was noted in 100% (6/6) of patients during angiographic assessments. On exploration, no gross tumors were found in 80% (4/5) of the cases that received limb-sparing surgery. Although disappearance of symptoms and sclerotic changes of bone tumor predicted a good response to treatment, the degree of decrease of tumor stains corresponded best with the extent of tumor necrosis. Our study verified the effectiveness of intraarterial cisplatinum and intravenous adriamycin infusion in treating primary hypervascular bone sarcomas. Further studies with more cases are necessary to define the optimal duration of postoperative adjuvant chemotherapy.

Adolescent↗
PubMed1986

Evidence for neural origin and PAS-positive variants of the malignant small cell tumor of thoracopulmonary region ("Askin tumor").

The differential diagnoses of childhood and adolescent tumors composed of small round cells include a distinctive clinicopathological entity called malignant small cell tumor (MSCT) of the thoracopulmonary region in childhood. In the present study, 15 such tumors that fulfilled the criteria by Askin et al. were examined for features of possible neural differentiation by light and electron microscopy (EM). With hematoxylin-eosin stain (H&E) the tumors were made up of small undifferentiated cells; rosette formation was noticed in four cases. By immunohistochemistry all 15 tumors were positive for neuron/specific enolase (NSE), which is a specific marker for neural elements and their tumors including neuroblastomas. Ten of 15 MSCT had positive PAS staining. Ultrastructurally dense core (neurosecretory) granules and cell processes indicative of neuronal differentiation could be recognized in 10 of 14 tumors. The dense core granules were often atypical. Filamentous cytoskeleton, never observed in Ewing's sarcoma, was often present. Based on the current results, MSCT of the thoracopulmonary region can be considered a peripheral neuroectodermal tumor with the possible origin in intercostal nerves. MSCTs are generally misdiagnosed as Ewing's sarcoma due to their primitive appearance in H&E sections and their periodic acid-Schiff positivity. NSE immunostaining, preferably augmented by electron microscopy, is necessary for their correct diagnosis.

Adolescent↗
PubMed2000

Targeted oncogenesis reveals a distinct tissue-specific utilization of alternative promoters of the human mineralocorticoid receptor gene in transgenic mice.

The human mineralocorticoid receptor (hMR) is a nuclear receptor mediating aldosterone action, whose expression is driven by two alternative promoters, P1 and P2, flanking the two first 5'-untranslated exons. In vivo characterization of hMR regulatory regions was performed by targeted oncogenesis in mice using P1 or P2 directing expression of the large T antigen of SV40 (TAg). While transgenic P1.TAg founders rapidly developed lethal hibernomas from brown fat, cerebral primitive neuroectodermal tumors and facial leiomyosarcomas occurred in P2.TAg mice. Quantitative analyses of mouse MR (mMR) and transgene expression indicate that P1 promoter was transcriptionally active in all MR-expressing tissues, directing strong TAg expression in testis and salivary glands, moderate in lung, brain, uterus, liver, and heart but, unlike mMR, rather low in colon and kidney. Importantly, the renal transgene expression colocalized with mMR in the distal nephron. In contrast, P2 promoter was approximately 10 times less potent than P1, with no activity in the brain and colon. Several immortalized cell lines were established from both neoplastic and normal tissues of transgenic mice. These cells exhibited differentiated characteristics and maintained MR expression, thus providing useful models for further studies exploring the widespread expression and functions of MR. Our results demonstrate that hMR gene expression in vivo is controlled by complex regulatory mechanisms involving distinct tissue-specific utilization of alternative promoters.

Adipose Tissue, Brown↗
PubMed2002

Expression and functional activity of the ABC-transporter proteins P-glycoprotein and multidrug-resistance protein 1 in human brain tumor cells and astrocytes.

The poor prognosis of glioma patients is partly based on the minor success obtained from chemotherapeutic treatments. Resistance mechanisms at the tumor cell level may be, in addition to the blood-brain barrier, involved in the intrinsic chemo-insensitivity of brain tumors. We investigated the expression of the drug-transporter proteins P-glycoprotein (P-gp) and multidrug-resistance protein 1 (MRP1) in cell lines (N = 24) and primary cell cultures (N = 36) from neuroectodermal tumors, as well as in brain tumor extracts (N = 18) and normal human astrocytes (N = 1). We found that a considerable expression of P-gp was relatively rare in glioma cells, in contrast to MRP1, which was constitutively overexpressed in cells derived from astrocytomas as well as glioblastomas. Also, normal astrocytes cultured in vitro expressed high amounts of MRPI but no detectable P-gp. Meningioma cells frequently co-expressed P-gp and MRP1, while, most of the neuroblastoma cell lines express higher P-gp but lower MRP1 levels as compared to the other tumor types. Both, a drug-exporting and a chemoprotective function of P-gp as well as MRP1 could be demonstrated in selected tumor cells by a significant upregulation of cellular 3H-daunomycin accumulation and daunomycin cytotoxicity via administration of transporter antagonists. Summing up, our data suggest that P-gp contributes to cellular resistance merely in a small subgroup of gliomas, but frequently in neuroblastomas and meningiomas. In contrast, MRP1 is demonstrated to play a constitutive role in the intrinsic chemoresistance of gliomas and their normal cell counterpart.

ATP Binding Cassette Transporter, Subfamily B, Mem↗
PubMed1991

Single-cell detection of ets-1 transcripts in human neuroectodermal cells.

The genes of the ets family are thought to code for a novel class of transcriptional factors. These proteins have a specific DNA-binding domain different from the basic domain of both the helix-loop-helix and leucine zipper families of DNA-binding proteins. The ets-1 gene product has been shown to bind to the enhancer region of the human T-cell receptor alpha gene during thymocyte ontogeny. This finding explains the high expression of ets-1 observed in T cells and the correlation between ets-1 expression and the expression of the T-cell receptor gene during fetal development. The ets-1 gene is also possibly biologically active in neural cells. By using RNA in situ hybridization analysis, we demonstrate the presence of ets-1 transcripts in cells of peripheral embryonal neuroectodermal tumors, specifically neuroepithelioma and neuroblastoma. In addition, the gene is found transcribed in Ewing's sarcoma, postulated to be ontogenetically related to tumors derived from the neural crest.

Gene Expression↗
PubMed1996

The role of high-dose chemotherapy and stem cell rescue in the treatment of malignant brain tumors.

The outcome for the majority of children with malignant brain tumors remains poor, despite surgery, irradiation and conventional chemotherapy. In an attempt to improve this poor outcome, strategies utilizing high-dose (potentially myeloablative) chemotherapy with autologous stem cell rescue have been developed. These studies, initially conducted in patients with recurrent brain tumors, have now been extended to patients with newly diagnosed malignant gliomas and to young children with various malignant brain tumors at diagnosis in an attempt to avoid irradiation to the brain. The results of several of these studies are summarized, demonstrating durable disease-free survival for a proportion of patients with recurrent malignant gliomas and medulloblastoma/primitive neuroectodermal tumors, as well as encouraging preliminary data in the newly-diagnosed patients.

Adult↗
PubMed2005

Favorable outcome of Ewing sarcoma family tumors to multiagent intensive preoperative chemotherapy: a single institution experience.

BACKGROUND: Aim of our study was to evaluate the efficacy of multiagent intensive preoperative chemotherapy in patients with Ewing sarcoma family tumors (ESFT), in order to succeed a better percentage of necrosis before surgical resection. PROCEDURE: Eighteen patients with ESFT were treated with the same multiagent intensive preoperative protocol. 5/18 patients had bone Ewings sarcoma (EWS) and 13/18 had peripheral primitive neuroectodermal tumor (PNET). None had metastases at diagnosis. Chemotherapy consisted of 5 or 6 cycles with vincristine, cisplatin, cyclophosphamide, and Adriamycin, followed by 12 cycles of vincristine, cyclophosphamide, and actinomycin-D. Five patients with EWS underwent total resection after 5-6 cycles of preoperative chemotherapy and prosthetic replacement was performed in two of them. In 3/13 patients with PNET the tumor was resected at diagnosis and in 1/13 after 5 cycles of chemotherapy, while 9/13 patients received chemotherapy only and/or radiotherapy. RESULTS: In patients with EWS, the histologic specimens of the resected tumors showed that tissue necrosis was 100% in four patients and 95% in one patient. The good histologic response reflects the effectiveness of this regimen in all ESFT. No patient had topical recurrence or developed metastatic disease during follow-up period (2-13 years, mean time 7.4 years). All patients had the scheduled cycles without delays or dose reductions. There were no major side effects of chemotherapy. CONCLUSIONS: The intensive chemotherapy schedule, comprising of 5-6 cycles preoperatively, seems to maximize the percentage of tumor necrosis, thus improving outcome. Our study implies that this combined therapy may improve the prognosis of ESFT.

Adolescent↗
PubMedDate not supplied

Esthesioneuroblastoma: cytologic features with differential diagnostic considerations.

A case of recurrent esthesioneuroblastoma was diagnosed by fine-needle aspiration of a midcervical mass. The cytologic features that characterize this uncommon neoplasm include uniform, small, round-to-oval cells with coarsely granular chromatin, multiple small nucleoli, prominent nuclear membranes, and scant cytoplasm. Morphologically and ultrastructurally, esthesioneuroblastoma cells resemble those of sympathetic neuroblastomas. Both tumors show rosette formation and minimal cellular pleomorphism, and, by electron microscopy, dense-core cytoplasmic granules can be identified. The cytologic recognition of esthesioneuroblastoma is important since it metastasizes to cervical lymph nodes accessible to fine-needle aspiration biopsy. In addition, the histogenesis of this unusual neuroectodermal tumor and its behavior are discussed.

Biopsy↗
PubMed1995

A phase I and II trial of dose-intensified cyclophosphamide and GM-CSF in pediatric malignant brain tumors.

PURPOSE: Cyclophosphamide is commonly used in the treatment of children with malignant brain tumors. The purpose of this study was to develop a multicycle, high-dose intensity cyclophosphamide regimen with granulocyte-macrophage colony-stimulating factor (GM-CSF) and to assess its activity against malignant glioma and primitive neuroectodermal tumor (PNET). METHODS: Twenty-three patients with brain tumors, including 15 with malignant glioma and six with PNET, were enrolled. Cyclophosphamide (1.8-2.25 g/m2/day for 2 days i.v.; total dose 3.6-4.5 g/m2) was administered and was followed by recombinant human GM-CSF (5 micrograms/kg/day s.c.) on days 3-11 or until the absolute granulocyte count reached 1.5 x 10(9)/L. RESULTS: With a total of 83 cycles administered, the mean dose intensity of cyclophosphamide ranged from 1.5 g/m2/week through cycle 2 (22 patients) to 0.8 g/m2/week through cycle 8 (two patients). No activity was seen against malignant glioma, and five of six patients with PNET had partial responses. The mean duration of a neutrophil count of < 0.5 x 10(9)/L was only 8 days; the platelet recovery was substantially longer. Fever during neutropenia occurred in 54 of 83 cycles. One patient died from transfusion-related graft-versus-host disease. CONCLUSIONS: A cyclophosphamide regimen equal to twice the dose intensity of that used in conventional therapy was administered. The regimen was active against PNET but inactive against malignant glioma.

Adolescent↗
PubMed1995

Neurologic and other disorders in relatives of pediatric patients with CNS tumors.

Abnormalities of embryogenesis and nervous system development may cause or contribute to the development of childhood brain tumors. To identify genetic or environmental factors that may be associated with etiologies of childhood central nervous system tumors, we examined family histories of 165 children with such tumors for the presence of neurologic disorders, including neural tube defects, mental retardation, seizures, and central nervous system tumors, as well as other cancers and birth defects. Only 1 patient, with the neurofibromatosis-Noonan syndrome, was confirmed to have an underlying syndromic diagnosis associated with central nervous system tumorigenesis. Families of 2 probands with posterior fossa primitive neuroectodermal tumors reported relatives with olivopontocerebellar atrophy. Although increased incidences of study disorders were not identified in this population, it is possible that within individual families one or more of these disorders is related to childhood central nervous system tumorigenesis.

Adolescent↗
PubMed1996

[An ultrastructural study of the ependymoma cells and cells of the ventric zone and neural canal of embryonic brain].

In order to make clear the characteristics of cell differentiation in ependymoma, 12 ependymoma cases were studied with light and electronic microscopy, and the tumor cells were compared with cells of the ventric zone and neural canal from 8 embryonic brains. 10 out of 12 ependymoma cases were also studied with immunohistochemistry staining. According to the ultrastructural findings, four types of ependymoma were classified, namely, the primary neuroectodermal tumor with ependymoblast differentiation, the ependymoblastoma, the ependymoma, and the subependymoma. Some ultrastructural features, such as long intermediate junction and microrosette formation were considered as the important criterion for differential diagnosis,. Neuroendocrine granulas were found in one case of 12 ependymomas which is considered to be heterogenic in differentiation.

Brain↗
PubMed2001

Automated nuclear image morphometry on fine needle aspiration smears of malignant round cell tumors.

OBJECTIVE: To analyze nuclear image morphometry in fine needle aspiration cytology smears of different groups of malignant round cell tumors (MRCTs) to evaluate its diagnostic role. STUDY DESIGN: In this study there were 55 cases of MRCT, consisting of 18 Ewing's sarcoma (EW), 10 neuroblastoma (NB), 5 non-Hodgkin's lymphoma (NHL), 6 rhabdomyosarcoma (RMS), 4 peripheral neuroectodermal tumor (PNET), 8 Wilm's tumor (WT), 2 retinoblastoma (RB) and 2 undifferentiated round cell tumor (URCT). A Leica image cytometer with Quantimet 600 software (Leica, Cambridge, U.K) was used to measure nuclear area, nuclear diameter, nuclear perimeter, nuclear convex perimeter (CP), nuclear roundness and nuclear convex area on hematoxylin and eosin-stained cytologic smears. At least 100 cells were studied in each case. RESULTS: The RB group of tumors showed the highest mean nuclear area (NA), convex area (CA), CP, diameter (D), perimeter (P) and roundness (R). RMS had the highest mean CA, and URCT had the highest mean roundness. ANOVA was performed on the tumors and showed significant differences for all the variables in all the groups (P < .000). All the morphometric data (except roundness) were significantly different in RMS versus all other MRCTs except RB. Similarly, morphometric data on WT were also significantly different from that on NHL. Most of the morphometric data (except CA and R) showed significant differences between RB and all other MRCTs except RMS. PNET, EW and NB could not be differentiated with those variables. CONCLUSION: RMS and RB could successfully be differentiated from all other MRCTs with the help of morphometry. It was not possible to differentiate RMS and RB by image cytometry (ICM) since the ICM data overlapped in those two groups. It was possible to differentiate WT and NHL with ICM. Nuclear ICM was not significantly different in the NB, PNET and ES groups, and probably ICM would not be very helpful to differentiate these groups of MRCT.

Biopsy, Needle↗
PubMed2002

Nonteratomatous tumors in the pediatric sacral region.

STUDY DESIGN: Two institutional experiences in nonteratomatous sacral tumors of the child were analyzed retrospectively. OBJECTIVES: To examine noncongenital nonteratomatous sacral tumors, which are more common in older infants and, as a group, are rare. SUMMARY OF BACKGROUND DATA: Pediatric sacral tumors usually occur in the newborn period, with most of these tumors being sacrococcygeal teratomas. Other common benign congenital tumors of the sacrum include lipomas, dermoids, and epidermoids. METHODS: Six patients were found in a 6-year period. Four patients underwent posterior resection of their tumors. One underwent a combined anterior and posterior approach. One patient underwent a posterior resection and will undergo a second stage anterior approach later to allow for chemotherapy and radiation to shrink the intrapelvic portion of the tumor. RESULTS: Ages ranged from 8 to 11 years. Three were males, and three were females. Five of six presented with back pain, three had constipation, and two had gait difficulties. Pathologies were diverse. They included ganglioneuroma (n = 1), myxopapillary ependymoma (n = 2), primitive neuroectodermal tumor (n = 1), aneurysmal bone cyst (n = 1), and Ewing's sarcoma (n = 1). No progression of disease has occurred in the follow-up period of 1.5 to 7 years (average, 5 years). Radical resection did not result in instability. CONCLUSIONS: In contradistinction to adults, in whom chordomas and metastases are the most common primary and secondary tumors, the pediatric group does not have a predominant pathology. Tumors may attain extremely large sizes and may be very vascular. Multiple therapeutic methods may be required, including adjuvant chemotherapy and, possibly, embolization. Because of the wide range of pathologies, prognosis is varied.

Back Pain↗