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Imaging-guided core biopsy for the diagnosis of malignant tumors in pediatric patients.

OBJECTIVE: We evaluated the ability of imaging-guided core biopsy to obtain sufficient tissue from pediatric tumors for a definitive diagnosis of malignancy on which treatment could be based. MATERIALS AND METHODS: Thirty-four biopsies (biopsies of the abdomen, 32; of the chest, 2) were performed on 34 children at presentation under CT or sonographic guidance using 14-, 18-, or both 14- and 18-gauge needles. A minimum of two tissue cores was obtained. Most biopsies were performed under general anesthesia, permitting other procedures to be performed. The biopsy results were confirmed by subsequent surgical pathology, bone marrow biopsy, biochemical or clinical features, and follow-up examination. RESULTS: The needle biopsy diagnoses were nephroblastoma (n = 11), neuroblastoma (n = 7), renal cell carcinoma (n = 2), synovial sarcoma (n = 1), non-Hodgkin's lymphoma (n = 2), clear cell sarcoma (n = 1), rhabdoid tumor (n = 1), pulmonary blastoma (n = 2), embryonal rhabdomyosarcoma (n 1), germ cell tumor (n = 1), adrenal carcinoma (n = 1), inflammatory tissue (n = 2), desmoplastic tumor of the mesentery (n = 1), and primitive neuroectodermal tumor (n = 1). In 28 patients, the results were confirmed as correct (22 with surgery and 6 with follow-up examination). Four patients required additional biopsy. In two of these patients, the core biopsy showed inflammatory tissue only, and an open biopsy of a different site was performed; the other two patients did not respond to therapy on the basis of needle biopsy results, and an open biopsy altered the diagnosis. Two patients with widespread disease were excluded because they did not respond to treatment and were too ill to undergo an open biopsy. Only one significant complication was recorded. CONCLUSION: Imaging-guided core biopsy is a safe and reliable means of obtaining sufficient tissue to make a confident histologic diagnosis of malignant pediatric tumors in a high percentage of patients.

Abdominal Neoplasms↗

Comparison of effects of doxorubicin and radiation on p53-dependent apoptosis in vivo.

The effects of doxorubicin and radiation on apoptosis, p53 expression, and tumor growth in human tumor xenografts were investigated. Human ependymoblastoma (NNE), primitive neuroectodermal tumor (YKP), glioblastoma (KYG) and small cell lung carcinoma (GLS) that are all transplantable to nude mice were treated with doxorubicin (8 mg/kg) or radiation (1 Gy). The histological study was performed by using TUNEL and p53 staining. Cytotoxic effects of doxorubicin and radiation were compared with no-treatment group by the growth curves and apoptotic index of tumor to each treatment. In NNE with wild-type p53, doxorubicin induced growth delay of tumors (tumor volume doubling time; 13.7+/-3.3 days in control group vs 30.4+/-1.5 days in doxorubicin group), but no growth delay of tumors in KYG and GLS with mutant type p53. While radiation-induced apoptosis appeared most frequently at 6 h after irradiation, doxorubicin-induced apoptosis had a tendency to appear later. Furthermore, although the frequency of doxorubicin-induced apoptosis was lower than that of apoptosis by 1 Gy irradiation, apoptotic cells appeared for many hours after the treatment. Doxorubicin-induced apoptosis may be correlated with p53 phenotype because apoptosis was induced only in tumor with wild-type p53, but it appeared less frequently and later than radiation-induced apoptosis.

Animals↗

[Synaptophysin in the nervous system and endocrine cells].

Synaptophysin is a major integral membrane glycoprotein of neuronal synaptic vesicles that is present in virtually all synapses and shows a high degree of evolutionary conservation in mammalian species. It has also been detected in numerous endocrine cell types where it is localized in the membrane of small synaptic-like vesicles which are thought to constitute a previously unknown secretory pathway. Antibodies directed against synaptophysin are a valuable tool for the immunohistochemical quantitation of synapses. Moreover, synaptophysin is a most reliable and specific marker molecule for normal and neoplastic neuroendocrine cells. In the nervous system, synaptophysin-positive tumors comprise ganglioneuromas, ganglioneuroblastomas, neuroblastomas, paragangliomas and primitive neuroectodermal tumors.

Animals↗

Acridine orange--RNA histofluorescence of sarcomas and small round cell tumors of childhood.

Forty-nine pediatric malignant neoplasms were stained with acridine orange (AO) fluorochrome to qualitatively evaluate cytoplasmic RNA content. The application of AO as a supplementary stain in surgical pathologic diagnosis is based on the premise that specific neoplastic cell types characteristically and consistently contain few or many cytoplasmic ribosomes. Primitive tumors such as Ewing's sarcoma and primitive neuroectodermal tumors showed negative or low-intensity AO-RNA cytoplasmic staining. Differentiated sarcomas such as rhabdomyosarcomas and lymphomas exhibited moderate to strong AO-RNA cytoplasmic fluorescence. Acridine orange--RNA staining provides an easy, convenient, and inexpensive adjunct in the histopathologic differential diagnosis of sarcomas. It is particularly useful for distinguishing Ewing's sarcomas from other small round cell sarcomas of childhood.

Acridine Orange↗

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↗

[Analysis of surface membrane antigens, cytoskeletal proteins and N-myc oncogene in pediatric solid malignant tumors, their diagnostic usefulness and relevant problems].

Neuroblastoma (NB), primitive neuroectodermal tumor (PNET), Ewing's sarcoma and rhabdomyosarcoma (RMS) are solid malignant tumors in childhood. Microscopically these tumors are grouped as small-round-cell tumors, and a different diagnosis is sometimes difficult. Cell surface membrane antigen, cytoskeletal protein and N-myc amplification and over-expression were analyzed in these cell lines and tumor tissues for the accurate diagnosis. NB and PNET could be distinguished from Ewing's sarcoma and RMS by the panel of monoclonal antibodies against cell surface membrane antigens. The cytoskeletal protein analysis is useful for the diagnosis of RMS and leiomyosarcoma. Alpha-smooth muscle actin and/or desmin were demonstrated in the S-type (epithelial-like) cells in 3 NB cell lines, suggesting the differentiation pathway of NB into smooth muscle cells. N-myc amplification and over-expression were observed in NB cell lines as well as one RMS cell line. The occurrence of N-myc amplification and over-expression in the RMS cell line cautions us against using N-myc as a distinguishable marker for NB.

Adolescent↗

Lipomatous differentiation in ependymomas: a report of three cases and comparison with similar changes reported in other central nervous system neoplasms of neuroectodermal origin.

Three cases of surgically removed ependymomas with lipomatous transformation of tumor cells are reported. Patients' ages were 13, 16, and 48 years at the time of operation. One patient's tumor was located in the third ventricle; the other two occupied paraventricular hemispheric white matter. Histologically all three cases fulfilled the criteria of ependymomas. In case 1, electron microscopy also confirmed this diagnosis, and preoperative radiologic studies (scans) suggested large amounts of lipids to be present in the tumor. Histologically, in all three cases many tumor cells contained fat droplets coalescing into a single large droplet, resulting in an appearance indistinguishable from adipocytes by conventional stains, but maintaining immunohistological positivity for glial fibrillary acidic protein and neuron-specific enolase in the cytoplasmic rims of the affected cells, attesting to their glial nature as opposed to being true adipocytes in a mixed glial/mesenchymal hamartoma. The alterations were also different from the "xanthomatous" changes seen in some gliomas. Lipomatous transformation of neuroectodermal tumor cells has been previously observed in neurocytomas, medulloblastomas, cerebellar and spinal cord astrocytomas, and primitive neuroectodermal tumors. Our three cases represent the first reported ependymomas with such changes. In medulloblastomas of adults, lipomatous changes have been found to signal relatively benign biologic behavior. So far, all three of our patients are doing well, but only more extended follow-up will show whether such benign behavior applies to lipomatous ependymomas as well.

Adolescent↗

Ependymal and choroid plexus tumors. Cytokeratin and GFAP expression.

Twenty-six ependymal and 15 choroid plexus tumors were examined with monoclonal antibody against cytokeratin using the avidin-biotin-peroxidase complex (ABC) technique. Serial sections were examined with antisera to glial fibrillary acidic protein (GFAP). In five ependymal tumors (one ependymoma, two papillary ependymomas, and two primitive neuroectodermal tumors [PNET] with ependymal cells), a variable number of cytokeratin-positive cells were present. Most tumor cells (except two PNET) were positive with GFAP antisera. Many cytokeratin-positive cells were present in all choroid plexus tumors. GFAP-positive cells were present focally in six of 11 papillomas and in one of four carcinomas. Although their staining patterns and distribution were clearly different, focal coexistence of cytokeratin and GFAP was observed in six papillomas and two ependymal tumors. Thus, some ependymal tumors (especially papillary ependymomas and occasional PNET) and many choroid plexus tumors have demonstrable positivity with antibody to cytokeratin, suggesting a transitional cell type with features of both ependyma and choroid plexus.

Carcinoma↗

Predictive value of clinical evaluation in the follow-up of children with a brain tumor.

BACKGROUND: During follow-up of children with a brain tumor, traditionally surveillance-imaging studies are done in addition to clinical evaluations. The purpose of this study was to determine the role of clinical evaluations by a multidisciplinary team for the detection of recurrent tumor. PROCEDURE: We retrospectively assessed the predictive value of clinical evaluation, using subsequent neuroimaging as the gold standard. Ninety-eight children with a newly diagnosed primary brain tumor were included in the study. In these patients, 393 imaging studies were done, 75 because of clinical suspicion of recurrence, and 318 for routine surveillance only. RESULTS: In 28 of these 75 imaging studies on clinical indications, a radiologic diagnosis of recurrence was made. Only 9 out of 318 routine surveillance imaging studies resulted in an unexpected diagnosis of recurrence. Thus, the overall positive predictive value of clinical evaluation was 37%; the overall negative predictive value was 97%. The negative predictive values for specific brain tumors varied from 91% (optical glioma) to 99% (primitive neuroectodermal tumors). CONCLUSIONS: An accurate multidisciplinary clinical evaluation has a very high negative predictive value. Consequently, the added value of surveillance imaging studies is limited. The role of such studies during the follow-up of children with brain tumors should be reconsidered.

Brain Neoplasms↗

[Musculoskeletal lymphomas].

Primary lymphomas of bone or skeletal muscle are rare entities. The most frequent among these diseases are primary non-Hodgkin's lymphomas of bone. They account for 3-5% of all bone tumors and 5% of all primary extranodal non-Hodgkin's lymphomas. Primary manifestations of Hodgkin's disease in bone or skeletal muscle are rarities. Primary non-Hodgkin's lymphomas of skeletal muscle are rarities as well. Primary non-Hodgkin's lymphomas of bone can be found in any patient age. A preference exists for the 3.-6. decade of life. The radiographic appearance of these entities resembles other aggressive bone tumors. Their differential diagnosis includes -- depending on the patient's age -- Ewing's sarcoma,malignant fibrous histiocytoma,metastases of small cell tumors and osteomyelitis.Further differential diagnoses are the peripheral primitive neuroectodermal tumor (PNET), osteosarcoma, eosinophilic granuloma and fibrosarcoma. Treatment of primary non-Hodgkin's lymphomas uses combinations of chemotherapy and radiation therapy. Operative treatment is reserved for the treatment of complications. The prognosis of primary non-Hodgkin's lymphomas is reflected by 10-year-survival-rates without recurrence of more than 80% in unifocal manifestations.

Bone Neoplasms↗

Rare occurrence of inactivating p53 gene mutations in primary non-astrocytic tumors of the central nervous system: reappraisal by yeast functional assay.

While it is established that p53 mutation plays a critical role in the carcinogenesis of astrocytic brain tumors, its role remains to be clarified for other types of tumors in the central nervous system (CNS). Using a yeast-based assay which tests the ability of human p53 to activate transcription, we analyzed p53 mutations in 85 non-astrocytic CNS tumors, including 4 benign neuronal tumors (3 central neurocytomas and 1 pineocytoma), 12 primitive neuroectodermal tumors, 14 germ cell tumors (7 germinomas, 7 non-germinomatous tumors), 4 craniopharyngiomas, 14 ependymomas, 22 schwannomas, 10 primary brain lymphomas in immunocompetent patients, and 5 bone tumors of the skull. The only tumors found to contain p53 mutations were 3 malignant lymphomas. The presence of mutations in these cases was confirmed by DNA sequencing. Given the high accuracy and sensitivity of the yeast assay and previous negative results using conventional techniques, this indicates that p53 mutation is a rare event in non-astrocytic CNS tumor types examined here.

Adolescent↗

EWS-ETS oncoproteins: the linchpins of Ewing tumors.

Ewing tumors, which comprise Ewing's sarcoma and peripheral primitive neuroectodermal tumors, are highly aggressive and mostly affect children and adolescents. Their molecular signature is a chromosomal translocation leading to the generation of EWS-ETS (or very rarely FUS-ETS) fusion proteins that are capable of transforming cells. These oncoproteins act as aberrant transcription factors due to the fusion of an ETS DNA binding domain to a highly potent EWS (or FUS) transactivation domain. Accordingly, many EWS-ETS target genes have been identified whose dysregulation could contribute to the development of tumor formation. Furthermore, EWS-ETS oncoproteins may impact on RNA splicing or affect other proteins through disturbing their ability to form functional complexes. The molecular knowledge gained so far from studying EWS-ETS oncoproteins has not only broadened our understanding of Ewing tumors but also improved the diagnosis of these highly undifferentiated tumors. In addition, several potential prognostic markers have been uncovered and novel therapies are suggested that may improve the still dismal survival rate of Ewing tumor patients.

Chromosomes, Human, Pair 16↗

Human SLITRK family genes: genomic organization and expression profiling in normal brain and brain tumor tissue.

Slitrk family proteins are characterized as integral membrane proteins that have two leucine-rich repeat (LRR) domains and a carboxy-terminal domain that is partially similar to trk neurotrophin receptor proteins. The LRR domains are similar to those of slit proteins. In a previous study, we showed that mouse Slitrk genes are expressed predominantly in neural tissue and have neurite-modulating activity in cultured neuronal cells. Their expression profiles as well as their functions vary among the family members. In this paper, we characterized the human SLITRK1, SLITRK2, SLITRK3, SLITRK4, SLITRK5, and SLITRK6 genes. The six genes are located in three clusters, on 3q, 13q, and Xq, respectively. Their expression was detected mainly in the brain, but the expression profile of each SLITRK was unique. SLITRK expression was also investigated in various types of brain tumor tissue. The results showed that all SLITRK genes are differentially expressed in brain tumors, including astrocytoma, oligodendroglioma, glioblastoma, medulloblastoma, and supratentorial primitive neuroectodermal tumor (PNET). Particularly interesting findings were that SLITRK3 expression was enhanced in tissue from several different types of tumors and SLITRK6 expression was highly selective. These results suggest that the human SLITRK genes are useful molecular indicators of brain tumor properties.

Adolescent↗

Evaluation of new monoclonal anti-MyoD1 and anti-myogenin antibodies for the diagnosis of rhabdomyosarcoma.

New monoclonal anti-MyoD1 and anti-myogenin antibodies were evaluated immunohistochemically to determine whether they are useful in discriminating rhabdomyosarcoma (RMS) from other soft tissue tumors in routinely processed sections. Neither MyoD1 nor myogenin was expressed in normal, mature striated muscle. In RMS, nuclear expression of MyoD1 and myogenin was found in 82 and 80% of non-overlapping cases, respectively. MyoD1 was generally expressed in small, primitive tumor cells, and larger cells exhibiting morphological evidence of skeletal muscle differentiation failed to express positive nuclear immunostaining. Positive nuclear staining for myogenin was stronger than that for MyoD1 in cases with abundant differentiated tumor cells, but was less prominent in cases in which small, primitive tumor cells predominated. No leiomyosarcomas, Ewing's sarcomas/peripheral primitive neuroectodermal tumors or other soft tissue tumors exhibited nuclear expression of MyoD1 or myogenin. In conclusion, both anti-MyoD1 and anti-myogenin antibodies are useful for diagnosing RMS and for discriminating RMS from other soft tissue tumors.

Actins↗

Mitotic recombination of chromosome 17 in astrocytomas.

Allelic combinations at seven loci on human chromosome 17 defined by restriction fragment length polymorphisms were determined in tumor and normal tissues from 35 patients with gliomas. Loss of constitutional heterozygosity at one or more of these loci was observed in 8 of the 24 tumors displaying astrocytic differentiation and in the single primitive neuroectodermal tumor examined. The astrocytomas showing these losses included examples of each adult malignancy grade of the disease, including glioblastoma (malignancy grade IV), and seven of them demonstrated concurrent maintenance of heterozygosity for at least one chromosome 17 locus. Determination of allele dosage together with the genotypic data indicated that the tumor chromosomes 17 were derived by mitotic recombination in 7 of the 9 cases with shared homozygosity of the region 17p11.2-pter in all cases. In contrast, tumors of oligodendrocytic, ependymal, or mixed cellular differentiation did not exhibit loss of alleles at any of the loci examined. These data suggest that the somatic attainment of homozygosity for loci on chromosome 17p is frequently associated with the oncogenesis of central nervous system tumors, particularly those showing solely astrocytic differentiation, and that mitotic recombination mapping is a useful approach towards the subregional localization of a locus whose rearrangement is involved in this disease.

Astrocytoma↗

The Ewing family of tumors and the search for the Achilles' heel.

The ideal cancer therapy would accomodate the specific biology of a tumor and be based upon understanding the mechanisms of malignancy. This vision has been the driving force in cancer research. However, the story of success in clinical cancer management is a story of empirie largely independent from progress in basic research. For the Ewing family of tumors (EFT) comprising Ewing's sarcoma and peripheral primitive neuroectodermal tumor, significant insights into the molecular basis have appeared recently. Some of last year's discoveries may have taken us closer to the identification of the Achilles' heel in this disease. The first clue has been obtained to the mechanism of chromosomal translocation, which constitutes a rate-limiting step in EFT pathogenesis. Also, researchers have progressed in understanding the control of EFT cell proliferation, differentiation, and death. A major role in these processes has been attributed to the EWS-ets gene rearrangement. Specific growth factor circuits appear to be involved in deregulated tumor cell growth. By analogy to heterologous cellular systems, it is possible to postulate an important functional role for CD99(MIC2) as it contributes to the malignant phenotype of EFT. In vitro, as well as the first in vivo, experimental evidence suggests that tumor cell expansion and spread can be counteracted by breaking these physiological pathways. Still, we are far from a tailored biological therapy of EFT. Before this goal may be achieved, we must seek further improvements and diversification of today's standard and intensified treatment regimens.

Animals↗

Benign brain stem lesions in pediatric patients with neurofibromatosis: case reports.

The symptoms and clinical courses of 4 patients with neurofibromatosis and lesions of the brain stem identifiable on computed tomographic and/or magnetic resonance imaging scans are described. Two patients underwent biopsy and both had low-grade astrocytomas with no evidence of anaplasia. Both received radiation and chemotherapy. The other 2 patients have been monitored without biopsy or treatment. Three patients are alive and clinically stable, having been followed up for an average of 4 years; neuroimaging studies have shown no change in their tumors. The fourth patient died of a supratentorial primitive neuroectodermal tumor. Imaging studies had shown no change in his brain stem lesion, which at autopsy was found to be a focal collection of fibrillary astrocytes. These data suggest that some patients with brain stem lesions and neurofibromatosis may have a prognosis distinctly different from that of the typical patient with a brain stem glioma. We recommend caution against aggressive operative and adjuvant therapy for brain stem lesions in patients with neurofibromatosis, unless progression of the lesion is documented clinically and/or by imaging.

Adolescent↗

Primary Ewing's sarcoma family of tumors arising from the broad ligament.

We report a case of a primary Ewing's sarcoma family of tumors (ESFT) that was an incidental finding in the broad ligament of a 53-year-old woman. ESFT now includes tumors previously described as Askin tumor, neuroepithelioma, extraskeletal Ewing's sarcoma, and peripheral primitive neuroectodermal tumor. This is because of the discovery that all of the above tumors contain a specific gene rearrangement involving chromosome 22q12. On microscopic examination, the tumor was composed of small, round cells with mild nuclear pleomorphism and scant eosinophilic cytoplasm. There were large areas of tumor necrosis and numerous mitoses. Immunohistochemically, there was strong membrane staining for CD99 and weak focal staining for CD56 and neuron specific enolase. Fluorescence in situ hybridization revealed a separation of the breakapart probe on chromosome 22q12 consistent with the presence of a gene rearrangement, supporting the diagnosis of ESFT. We believe the importance of recognizing the existence of a primary ESFT in the broad ligament as some primary tumors of the gynecological tract and of other systems may resemble it histologically. To the best of our knowledge, our case is the second case of extraskeletal Ewings sarcoma arising from the broad ligament but the first case that is confirmed by strong CD99 positivity and supported by fluorescence in situ hybridization.

12E7 Antigen↗