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PubMed1995

Thallium-201 scintigraphy in pediatric soft-tissue tumors.

UNLABELLED: Thallium-201 has been used as a tumor imaging agent in adults with lymphoma, brain tumors, thyroid carcinoma and bone sarcomas. The application of 201Tl in pediatric oncology has been very limited. METHODS: Whole-body 201Tl studies were incorporated into the imaging protocols of 45 children with solid soft-tissue tumors. Bone and 67Ga scans as well as 131I-MIBG scans for patients with neuroblastoma were obtained. RESULTS: Seventeen children with lymphoma, five with Hodgkin's disease and twelve with non-Hodgkin's lymphoma (NHL) were studied. All of the patients with Hodgkin's disease showed avid uptake of 201Tl and 67Ga. The six patients with B-cell NHL had positive 67Ga scans and four had positive 201Tl scans. There was variable uptake in T-cell and undifferentiated lymphoma with an overall sensitivity of 69% for 201Tl and 85% for 67Ga. In 14 patients with rhabdomyosarcoma, 10 (71%) had positive 201Tl scans and 11 (79%) had positive 67Ga images. Gallium and thallium scans detected lesions equally. There was poor uptake of 201Tl in the six children with neuroblastoma. Primary tumor and metastases were detected more readily with the bone and MIBG scans. Three children with Wilms' tumor had poor or no uptake on 201Tl images, two of three patients with histocytosis had no significant uptake and one patient had mild uptake of 201Tl. One patient with primitive neuroectodermal tumor had positive 201Tl and 67Ga images and one patient with a neurofibrosarcoma had negative 201Tl and 67Ga images. There was no correlation with histological types of tumor or disease staging. CONCLUSION: This study shows significant uptake of 201Tl in many pediatric solid soft-tissue tumors. Additional study is needed to determine 201Tl effects on treatment response and tumor viability. Also, more studies are needed to assess 201Tl delayed images to determine if there is more tracer concentration in the tumors.

3-Iodobenzylguanidine↗
PubMed1995

Desmoplastic neurotropic melanoma. A clinicopathologic analysis of 28 cases.

BACKGROUND: Desmoplastic neurotropic melanoma (DNM) is a rare variant of malignant melanoma, the natural history and histogenesis of which still are being defined. METHODS: The clinical and histologic features of 28 cases of DNM were studied. All published cases of DNM to date were reviewed. Paraffin sections from 26 cases were investigated with a panel of 10 tissue markers. The ultrastructural features of seven cases were evaluated. RESULTS: A comparison of this study's findings with that of other published cases revealed many similarities regarding clinical and pathologic findings and outcome. The patients were white (15 men:13 women; mean and median age, 59 years; range, 22-83 years). Most tumors were located on the head and neck (75%) and were nonpigmented (57%). An associated intraepidermal melanocytic proliferation was identified in 85% of the patients (lentigo maligna in 56%). Histologically, the dermal tumors were composed of tapered, nonpigmented spindle cells in peripheral nerve sheath patterns resembling neuromas, schwannomas, neurofibromas, and perineurial proliferations accompanied by variable neurotropism and desmoplasia; desmoplasia was the most notable feature in most tumors. The mean depth of tumor invasion was 4.1 mm (range, 0.32-9.0 mm). Tumors with continuity between the epidermal and dermal components had a significantly thinner depth of invasion and a more extensive intraepidermal melanocytic proliferation than those tumors with a grenz zone between the two components (2.3 mm vs. 4.6 mm, P = 0.015). Mitotic activity ranged from 0/HPF in 10 cases, 1-6/high power field (HPF) in 12 cases, and to greater than 6/HPF in 4 cases. An ulcer was present in 5/27 tumors, regression in 4/27, a microsatellite in 1, and brisk and had nonbrisk tumor infiltrating lymphocytic responses in 2 and 14, respectively. Vimentin was uniformly positive and keratins AE1.3 and Cam 5.2 and Leu-7 were uniformly negative. S100 protein, also uniformly positive, had patchy reactivity in most tumors that expressed EMA (43%). Smooth muscle actin (52%), neuron-specific enolase (42%), and FXIIIa (30%) had patchy positivity. HMB-45 was reactive only in the epidermal and superficial papillary dermal component in 21% of cases. Ultrastructurally, the common features were long, often intertwining cellular processes, intercellular junctions, and discontinuous basal lamina. Melanosomes were not identified. Follow-up data available on 26/28 patients (mean, 36 months; median, 24 months; range, 5-132 months) showed 20 (70%) alive without disease, 2 alive with disease and 3 dead from disease. Seven patients had recurrent local tumor (multiple in four); four had lymph node metastases, and three had visceral metastases. Patients with recurrent disease of any type had significantly thicker tumors (5.4 mm vs. 3.4 mm, P = 0.046) and were more likely to have an ulcerated tumor (P = 0.03). Actuarial 5-year survival for tumors with greater than a 4-mm thickness was 72%, which was greater than that for other types of melanoma with greater than a 4-mm thickness. CONCLUSIONS: Desmoplastic neurotropic melanomas are neuroectodermal tumors that usually arise from an intraepidermal melanocytic proliferation but rarely develop de novo in the dermis. Schwannian and perineurial differentiation may account for the desmoplasia and neurotropism encountered in these neoplasms. Desmoplastic neurotropic melanomas present at a more advanced stage locally and may be associated with a better survival than associated with conventional melanomas of similar depth of invasion.

Adult↗
PubMed1990

Brain tumors diagnosed in the first year of life in five Far-Eastern countries. Statistical analysis of 307 cases.

A statistical survey is presented of brain tumors diagnosed in the first year of life (from five Far-Eastern countries) in relation to the racial differences in tumor types, congenital factors, and general clinical features. Of the 307 cases collected, 262 were verified histologically, and astrocytomas comprised 23.3%, medulloblastomas 17.2%, ependymomas 11.1%, choroid plexus papillomas 10.7%, teratomas 8.4%, primitive neuroectodermal tumors 4.2%, meningiomas 2.3%, and others 22.9%. There were statistically significant racial differences in comparison with the worldwide survey done by the International Society for Pediatric Neurosurgery Education Committee (1987) on the same subject. In the Far-Eastern population, medulloblastoma and teratoma were more common (P less than 0.05), whereas astrocytoma was less frequent (P less than 0.01) than reported in the worldwide survey. The malformative factors were suggested in 18 cases in which various associated congenital anomalies were observed. Vascular anomalous lesions, mostly in the extracranial organs, were most common, comprising 61.1% of the associated malformations. Hereditary factors were less commonly demonstrated in these tumors than were anomalies in the major congenital central nervous system. Among the 307 cases, there was one instance (0.3%) of nearly identical tumors occurring in twin brothers. The specific clinical manifestations of brain tumors involving the immature brain were again apparent in this survey, as were the poor survival rates and poor functional prognosis.

China↗
PubMed2004

Atypical teratoid/rhabdoid tumor: an unusual presentation.

Atypical teratoid/ rhabdoid tumor (AT/RT) of the central nervous system is a rare, highly aggressive malignancy of infancy. Although it is reported infrequently in the literature, it has often been histologically confused with a primitive neuroectodermal tumor (PNET)/medulloblastoma (MB) but has a much worse prognosis. We present an infant with two AT/RT tumors, one suprasellar in location and the other within the vermis without evidence of tumor elsewhere. What makes this case unusual is that there were two separate lesions in different cranial compartments, with no evidence of subarachnoid seeding. In addition, the lesions had different magnetic resonance imaging (MRI) characteristics even though they were histologically the same.

Female↗
PubMed2001

A review of the cytogenetics of 58 pediatric brain tumors.

We describe the cytogenetic results of 58 pediatric central nervous system (CNS) tumors of variable histology, investigated between 1992 and 2000. Successful cytogenetics were obtained for 53 patients, with clonal chromosome abnormalities demonstrated in 25. Notable findings included (1) 2p abnormality in four primitive neuroectodermal tumors (PNET); (2) 1p loss in four low-grade gliomas and two PNET; (3) telomeric associations in one pilocytic astrocytoma; (4) chromosome 7 gain in four astrocytomas and two PNET; (5) 17p loss in four PNET; (6) double minutes in one PNET and three glioblastomas; and (7) chromosome 10 loss in four PNET. Higher grade tumors demonstrated greater karyotype complexity. Low-grade tumors showed either minimal simple chromosome changes or a normal karyotype. Chromosome abnormalities were more frequent in supratentorial tumors than their infratentorial counterparts. Our results add weight to the limited existing body of cytogenetic documentation for pediatric CNS tumors and provide further evidence that 2p loss is a consistent region of chromosome involvement in PNET. We advocate further studies of CNS tumors, in particular, to evaluate the importance of 2p changes and to compare cytogenetic results for supratentorial tumors and their infratentorial counterparts.

Astrocytoma↗
PubMed1998

Extrarenal rhabdoid tumors of soft tissue: a clinicopathologic and immunohistochemical study of 18 cases.

Rhabdoid tumor is a well-accepted clincopathologic entity among childhood renal neoplasms; similar tumors have been described in extrarenal locations. We present the clinicopathologic profile and the immunohistochemical features of a series of soft tissue rhabdoid tumors. Twenty-eight cases coded as extrarenal rhabdoid tumor (ERRT), RT, possible ERRT, and "large cell sarcoma" were retrieved from the Armed Forces Institute of Pathology soft tissue registry. The tumors were reclassified according to strict criteria by light microscopy, clinical information, immunohistochemistry, and, in some cases, electron microscopy. Soft tissue rhabdoid tumor (STRT) was defined as (1) a tumor composed of noncohesive single cells, clusters, or sheets of large tumor cells with abundant glassy eosinophilic cytoplasm, an eccentric vesicular nucleus, and an extremely large nucleolus; (2) positivity for vimentin and/or cytokeratin or other epithelial markers by immunostaining; and (3) exclusion of other tumor types with rhabdoid inclusions (melanoma, other sarcomas, carcinoma). Eighteen cases met our criteria for soft tissue rhabdoid tumors. The median patient age was 13 years (range, 6 months to 56 years). Ninety-four percent of STRT cases were positive for vimentin and 59% for pan-cytokeratin. Sixty-three percent and 60% were positive for CAM 5.2 and EMA, respectively. Seventy-nine percent stained for at least one epithelial marker; 76% stained for both vimentin and epithelial markers simultaneously. Forty-two percent stained for MSA, and 14% for CEA and SMA. CD99, synaptophysin, CD57 (Leu-7), NSE, and focal S100 protein were identified in 75%, 66%, 56%, 54%, and 31% of the STRT cases, respectively. All STRT cases examined were negative for HMB-45, chromogranin, BER-EP4, desmin, myoglobin, CD34, and GFAP. Follow-up examination in 61% of the STRT patients revealed that 64% of patients died of disease within a median follow-up interval of 19 months (range, 4 months to 5 years); 82% had metastases to lung, lymph nodes, or liver; 22% had local recurrences before metastasis; and 18% were alive without known disease status (median, 5.5 years). Soft tissue rhabdoid tumor is a highly aggressive sarcoma, predominantly of childhood. Besides having nearly consistent coexpression of vimentin and epithelial markers, STRTs show positivity for multiple neural/neuroectodermal markers that overlap with those of primitive neuroectodermal tumor.

Adolescent↗
PubMed2000

Isochromosome 7q in adult Wilms' tumors: diagnostic and pathogenetic implications.

Wilms' tumors affecting adults are rare and are thought to have a worse prognosis than similar stage tumors in the pediatric population. To understand these tumors better, the authors reviewed their multi-institutional experience in a series of nine lesions diagnosed as Wilms' tumors in adults. In addition to histologic and immunohistochemical examination, they performed cytogenetic analysis and fluorescence in situ hybridization. On review, four cases were reclassified: two "blastema only" as Ewing's sarcoma/primitive neuroectodermal tumor and the other two as clear cell sarcoma of soft parts and sarcoma not otherwise specified (NOS). Of the remaining five cases, three exhibited biphasic histology and two were triphasic. In this group, there were three women and two men, and patient age ranged from 17 to 37 years (median age, 26 years). Tumor size was large and ranged from 10 to 31 cm (median tumor size, 12.5 cm). Histologically, the tumors showed the typical features of Wilms' tumors with varying amounts of blastema (n = 5), epithelium (n = 5), and stroma (n = 2). No tumors contained anaplasia, and persistent renal blastema was not identified in the non-neoplastic kidney in any specimen. All tumors were positive for cytokeratins (CK7, n = 3; pankeratin, n = 5), and one tumor was weakly positive for CD99 (0-13). Molecular analysis including dual color fluorescence in situ hybridization (all tumors), and cytogenetic analysis (n = 2) disclosed the presence of isochromosome 7q in three of five tumors whereas all tumors were diploid with respect to chromosome 12. Follow-up data ranged from 6 to 133 months (median follow-up, 82 months) with progression in only one patient who had stage IV disease with lymph node and lung metastases at presentation. The authors conclude that adult Wilms' tumor has been overdiagnosed. Most "blastema-only" tumors in adults are not Wilms' tumors, and in an adult, biphasic morphology should be the minimum criteria for their diagnosis. Using strict diagnostic criteria, adult Wilms' tumors have a relatively favorable prognosis. The characteristic findings of isochromosome 7q, lack of trisomy or tetrasomy for chromosome 12, and absence of persistent renal blastema suggest that the pathogenesis of Wilms' tumors in adults may be different than in the pediatric population. These genetic features may be helpful in distinguishing adult Wilms' tumors from other primary renal tumors.

Adolescent↗
PubMed1996

Trilateral tumors in four different lines of transgenic mice expressing SV40 T-antigen.

PURPOSE: A line of transgenic mice containing the simian virus (SV) 40 T-antigen (T-ag) gene driven by the beta-luteinizing hormone (BLH) promoter developed bilateral retinoblastoma and primitive neuroectodermal tumors (PNET) of the midbrain. Midbrain tumors arose from the subependymal layer of the cerebral aqueduct. Bilateral ocular and brain tumors ("trilateral") were found in three other SV40 T-ag transgenic murine lines containing different promoters (murine interphotoreceptor retinoid-binding protein (IRBP), human IRBP, and alpha A-crystallin). To gain insight into the regulatory mechanisms involved in central nervous system tumorigenesis, the authors examined brain tumors from four lines of SV40 T-ag mice with different promoters. METHODS: Formalin-fixed brain tumors were examined from four lines of transgenic mice containing different promoters linked to the protein coding region of the enhancerless SV40 T-ag oncogene. Transgenes contained the following promoters: BLH, mouse 1.8-kb IRBP, human 1.3-kb IRBP, and alpha A-crystallin. RESULTS: Mice with a 1.8-kb IRBP promoter develop retinal photoreceptor and pineal tumors. Intracranial tumors arising from the subependymal layer of the third ventricle also were observed. Mice with a 1.3-kb IRBP promoter exhibit bilateral retinal PNET and PNET originating from the subependymal layer of the third ventricle. Mice with the alpha A-crystallin promoter exhibit bilateral lens tumors and PNET of the midbrain. CONCLUSIONS: Ocular tumors in these mice may be ascribed to the promoter-driven, tissue-specific expression of SV40 T-ag. The common finding of PNET arising from the subependymal layer of the diencephalon is unlikely to be promoter related. These findings indicate that a regulatory region specific to the subependymal layer of the cerebral aqueduct and third ventricle resides in the structural region of the SV40 T-ag gene.

Animals↗
PubMed2005

Ifosfamide, carboplatin, and etoposide (ICE) reinduction chemotherapy in a large cohort of children and adolescents with recurrent/refractory sarcoma: the Children's Cancer Group (CCG) experience.

BACKGROUND: The prognosis for children with recurrent/refractory sarcomas is poor. We determined the overall response rate (ORR) and overall survival (OS) of children with recurrent/refractory sarcomas who were given ifosfamide, carboplatin, and etoposide (ICE) in three Children's Cancer Group (CCG) phase I/II trials. PROCEDURE: Children with recurrent/refractory sarcoma were treated with ifosfamide (1,800 mg/m2/day on day 0-4), carboplatin (400 mg/m2/day on day 0-1), etoposide (100 mg/m2/day on day 0-4) and either rhG-CSF (10 microg/kg/day vs. 5 microg/kg/day, CCG-0894, 71 patients), PIXY321 (500-1,000 microg/m2/day, CCG-0924, 14 patients), or rhG-CSF (5 microg/kg/day) and IL-6 (2.5-5 microg/kg/day, CCG-0931, 12 patients). RESULTS: Ninety-seven patients were evaluable for tumor response, 56 male and 41 female, median age 14.1 years (range 2.8-22.5 years). Tumor types were osteosarcoma (OTS) (n = 34), rhabdomyosarcoma (n = 27), Ewing sarcoma (EWS) (n = 21), soft tissue sarcoma-not otherwise specified (n = 5), undifferentiated sarcoma (n = 6), fibrosarcoma (n = 2), peripheral primitive neuroectodermal tumor (n = 1), and extraosseous Ewing (n = 1). The ORR was 51% (27% complete response [CR]). OS at 1 and 2 years was 49% and 28%, respectively. Patients with CR or partial response (PR) had significantly increased 1- and 2-year OS, 71% and 41%, respectively, (P < 0.001). Rhabdomyosarcoma patients with embryonal histology had significant improvement in 1- and 2-year OS: 82% and 46%, respectively, compared with other histologies, (P < 0.005). CONCLUSIONS: The ORR to ICE reinduction chemotherapy in children with recurrent/refractory sarcoma was 51%. OS of 1 and 2 years appeared significantly improved in patients who had CR or PR following ICE reinduction therapy or who had rhabdomyosarcoma with embryonal histology.

Adolescent↗
PubMed1991

Genetic alterations in glioma and medulloblastoma.

Multiple genetic changes take place during tumor development and progression. These genetic changes result in inactivation of tumor suppressor genes and activation of proto-oncogenes. Frequent genetic changes observed in gliomas are losses of chromosomal regions on 9p, 10q, 13q, 17p and on 22. Loss of 10q is seen in more than 80% of the glioblastoma multiforme (GBM) tumors suggesting the presence of a gene critical for GBM formation on this chromosome. Amplification of epidermal growth factor receptor gene and expression of platelet derived growth factor and fibroblast growth factor genes are also common among gliomas. The most common genetic abnormality found in medulloblastomas is loss of 17p. The C-myc gene is amplified in a few primary tumors, but the incidence of amplification is higher in medulloblastoma derived cell lines. These findings suggest that the same two genetic processes, gene amplification and regional chromosomal loss, which characterize other primitive childhood neuroectodermal tumors such as retinoblastoma and neuroblastoma are also important in medulloblastomas.

Brain Neoplasms↗
PubMed2000

34betaE12 Cytokeratin Immunodetection in the Differential Diagnosis of Small Cell Tumors of Lung.

The group of small cell tumors of the lung includes fine following: (1) small cell carcinoma (SCC) of neuroendocrine (NE) origin, (2) poorly differentiated squamous carcinoma, (3) the rare basaloid (basal cell) carcinomas, and (4) malignant lymphomas, primitive neuroectodermal tumors (PNETs), and rhabdomyosarcomas. The differential diagnosis among these entities carries a heavy therapeutic impact but may be difficult in small biopsy specimens or in cytologic material, especially if necrosis or artifactual alterations are present. The use of additional techniques such as immunostaining for NE markers is not always helpful, since immunoreactive chromogranin A is detectable in only a small percentage of small cell carcinomas. It has recently been reported that in the aerodigestive tract 34betaE12 cytokeratin (CK) immunostaining selectively labels non-NE carcinomas, including squamous cell carcinoma, adenocarcinoma, and the rare basaloid carcinoma. We evaluated the role of such CK immunodetection in the differential diagnosis of small cell lung tumors in cytologic and biopsy specimens. Eighty-one lung tumors diagnosed by means of endoscopic bronchial biopsy, fine needle aspirate, or bronchial washing were collected. They included 43 small cell NE carcinomas and 38 cases used as controls (comprehensive of 2 large cell neuroendocrine carcinomas, 4 carcinoid tumors, 30 cases of non-NE lung carcinomas, 2 cases of bronchial infiltration by non-Hodgkin lymphomas). 34betaE12 CK immunoreactivity was found in 29/30 cases of non-NE carcinomas, but in only 3/43 SCCs. The latter showed positivity in only a few scattered cells. The 2 cases of bronchial infiltration by malignant lymphoma as well as the 4 cases of carcinoid tumors and the 2 cases of large cell neuroendocrine carcinomas were negative. These findings were confirmed in the surgical specimens of operatedon cases. We conclude that, in lung carcinoma biopsies showing a small cell pattern, presence of 34betaE12 CK immunoreactivity favors a non-NE carcinoma, whereas its absence supports the diagnosis of SCC. Int J Surg Pathol 8(4):317-322, 2000

Journal Article↗
PubMed2000

Targeted cytokines for cancer immunotherapy.

Targeting of cytokines into the tumor microenvironment using antibody-cytokine fusion proteins, called immunocytokines, represents a novel approach in cancer immunotherapy. This article summarizes therapeutic efficacy and immune mechanisms involved in targeting interleukin-2 (IL-2) to neuroectodermal tumors using ganglioside GD2-specific antibody-IL-2 fusion protein (ch14.18-IL-2). Treatment of established melanoma metastases with ch14.18-IL-2 resulted in eradication of disease followed by a vaccination effect protecting mice from lethal challenges with wild-type tumor calls. In a syngeneic neuroblastoma model, targeted IL-2 was effective in the amplification of a weak memory immune response previously induced by IL-12 gene therapy using an engineered linear version of this heterodimeric cytokine. These findings show that targeted IL-2 may provide an effective tool in cancer immunotherapy and establish the missing link between T cell-mediated vaccination and objective clinical responses.

Animals↗
PubMed1989

Peripheral neurogenic tumors of the soft tissues in children and adolescents: a clinicopathologic study of 139 cases.

A review of over 900 soft tissue neoplasms in children and adolescents revealed 139 neurogenic tumors in 122 patients from newborn to 20 years of age, which had been accessioned in a 25-year period. Based upon clinicopathologic criteria, 84 (60%) tumors were regarded as unequivocally benign or borderline and the remaining 55 (40%) were malignant. The average age at diagnosis for the entire series was 10 years; the sex distribution was approximately equal; and the trunk (66, 48%) was the most frequent topographic site, followed by the head and neck (39, 29%) and extremities (31, 23%). Eighteen tumors (13%) were recognized at birth. Twenty-one patients (17%) had the stigmata of von Recklinghausen's neurofibromatosis (VRN). Neurofibromas and cellular peripheral nerve sheath tumors accounted for 43% (60 cases) of the diagnoses; these 60 neoplasms occurred in 41 patients, 12 of whom had VRN. The second largest category of neoplasms (38 cases, 28%) was the primitive neuroectodermal tumor (PNET) including the subset of "malignant small cell tumor of thoracopulmonary origin" or Askin tumor. The PNETs other than the Askin tumor (26 cases) presented mainly on the trunk (63%) and head and neck region (33%), showed a male predilection (58%) and had a mean age at diagnosis of 7 years. Askin tumors (12 cases) were, by definition, confined to the chest wall or thoracic cavity, showed a female predilection (71%), and presented in the second decade (82%, mean age 14 years). There were 16 (11%) malignant peripheral nerve sheath tumors, seven of which occurred in children with VRN. Six other categories of neurogenic tumors constituted the remaining cases. Our findings indicate that neurogenic neoplasms are an important nosologic group of soft tissue tumors in the pediatric population.

Adolescent↗
PubMedDate not supplied

Cyclooxygenase-2 (COX-2) overexpression in childhood brain tumors.

The overexpression of COX enzymes has been demonstrated in human neoplasms at various sites, including the colon, gastrointestinal tract, lung, skin and recently in brain tumors. In this study, COX-2 receptor overexpression in primary childhood brain tumors was determined and the distribution pattern of COX-2 receptors was examined. A sensitive, 4-step, alkaline phosphatase conjugated antigen detection technique was used and a specific monoclonal antibody for medulloblastomas/ primitive neuroectodermal tumors (MEDs/PNETs), anaplastic, high-grade astrocytomas (ASTRs) and in glioblastoma multiformes (GMs) was employed. All of the 14 MEDs/PNETs observed demonstrated high levels of immunoreactivity (overexpression), with the highest immunostaining intensity (grades A and B). However, of the 14 subtypes of astrocytic tumors examined, the COX-2 receptor expression level did not even approach those of the MEDs/PNETs levels. However, significant differences were found when comparing low grade pilocytic ASTRs to high grade anaplastic ASTRs and glioblastomas. In two low grade pilocytic ASTRs, the expression level never exceeded 20%, while in high grade glial tumors (6 anaplastic ASTRs and 6 GMs) 30 to 50% of the tumor cells overexpressed COX-2 receptors, documenting an increase in COX-2 receptor overexpression with the increasing grade of the astrocytic tumor. In view of these findings, it would appear likely that COX-2 inhibitors may represent a chemo-preventive tool in treating childhood brain tumors, which are the leading cause of solid tumor cancer death in children under the age of 20.

Brain Neoplasms↗
PubMed2004

C-kit expression and mutational analysis in medulloblastoma.

The proto-oncogene c-kit is a receptor tyrosine kinase recognized to initiate essential signal transduction pathways that transmit biological signals for cellular proliferation, differentiation, and metastasis. Aberrant expression or mutation of c-kit has been shown to be involved in the pathogenesis of many cancers. Studies using imatinib mesylate (STI 571, Gleevec, Novartis, East Hannover, NJ, USA), an inhibitor of the tyrosine kinases brc-abl, c-kit, and PDGFR, have shown significant response in patients with chronic myelogenous leukemia and gastrointestinal stromal tumor. With the aim of identifying additional groups of tumors that may use the stem cell factor/c-kit pathway and, secondarily, may be responsive to imatinib mesylate treatment, we looked at the expression of c-kit in medulloblastoma. Medulloblastoma, a highly invasive primitive neuroectodermal tumor of the cerebellum, is the most common, malignant central nervous system tumor of childhood. Histologic features of medulloblastoma have failed to provide an accurate prediction of the clinical-biological behavior of these tumors. Characterizing the genetic events that play a role in the biology of these tumors may allow for molecular sub-typing and could lead to the development of novel therapeutic strategies. This study evaluated c-kit expression and mutational status in 10 medulloblastoma tumor samples. All 10 medulloblastoma tumors expressed c-kit by reverse transcriptase-polymerase chain reaction and 9 by immunohistochemical analysis. All tumor samples were screened for mutations in exons 9, 11, and 13 of the c-kit gene by direct sequencing. No sequence abnormalities were detected in these exons. These experiments lead us to the conclusion that c-kit activation in medulloblastoma is independent of mutation.

Adolescent↗
PubMed2000

Leukocyte common-antigen-related tyrosine phosphatase receptor: altered expression of mRNA and protein in the New England Deaconess Hospital rat line exhibiting spontaneous pheochromocytoma.

Regulation of cell proliferation by protein tyrosine phosphatases (PTPs) suggests that PTPs are important tumor suppressor genes. The gene encoding the leukocyte common-antigen-related (LAR) PTP receptor maps to chromosome 1p32-33, a region in which loss of heterozygosity is associated with human pheochromocytoma and other neuroectodermal tumors. The rat pheochromocytoma PC12 cell line was originally derived from the transplantable P259 tumor originating from the New England Deaconess Hospital (NEDH) line of Wistar inbred rats. Compared with their Wistar counterparts, 1-2-year-old NEDH rats exhibit a high incidence of spontaneous pheochromocytomas. This study investigates whether levels of LAR transcripts and protein are altered in NEDH adrenal tissue prior to tumor onset. In addition, alternative splicing of an LAR extracellular domain [LAR alternatively spliced element-c (LASE-c)], regulating LAR interaction with extracellular matrix components, was examined. These changes in LAR expression and alternative splicing were hypothesized to be more pronounced in tumor tissue and PC12 cells. Northern blot analysis demonstrated the presence of the approximately 5 kb LAR transcript in all cell lines examined, except PC12. In adrenal medulla tissue harvested from 2-3-month-old rats, LAR approximately 8 and approximately 5 kb transcript expression was decreased in NEDH compared with Wistar samples. RT-PCR demonstrated increased splicing of the LASE-c 27 bp alternatively spliced insert in the LAR extracellular domain in NEDH adrenal medulla tissue. Even greater LASE-c splicing was detected in adrenal medulla tumor tissue derived from 12-month-old NEDH rats and in PC12 cells. Western blot analysis demonstrated decreased levels of LAR protein and increased levels of LASE-c containing LAR protein isoforms in NEDH adrenal medulla tissue. These studies demonstrate that patterns of altered LAR expression present in PC12 cells and in pheochromocytoma tumor tissue are also present in adrenal tissue predisposed to a high incidence of spontaneous pheochromocytoma.

Adrenal Cortex↗
PubMed1983

Distribution of immunoreactive S-100 protein in pediatric brain tumors.

The distribution of S-100 proteins was examined in 98 pediatric brain neoplasms with rabbit antiserum to S-100 protein, utilizing the peroxidase-antiperoxidase (PAP) immunohistochemical technique. Positive cytoplasmic immunoreactivity was present in 22 of 24 astrocytomas, both oligodendrogliomas, eight of 13 ependymomas, all 11 choroid plexus tumors, all nine schwannomas, two of six meningiomas, and both meningeal melanomas. Mixed cytoplasmic immunoreactivity was present in both gangliogliomas, all seven craniopharyngiomas, and the only hemangioblastoma. No cytoplasmic immunoreactivity was found in primitive neuroectodermal tumors or germinoma. Nuclear immunoreactivity was present in some cases. Because of the broad spectrum of apparent immunoreactivity with S-100 antiserum, S-100 protein cannot be used as a specific marker of glial or Schwann cell tumors.

Astrocytoma↗
PubMedDate not supplied

Synchronous presentation of an Askin tumor and a plasmacytoma in an adult patient.

Askin tumor, or malignant small round cell tumor of the thoracopulmonary region, is an extremely infrequent entity occurring primarily in children and adolescents. Its histopathologic and cytogenetic features suggest that it belongs to the family of Ewing's sarcoma and primitive neuroectodermal tumors. We report the case of a 43-year-old woman affected by an Askin tumor with bone metastases at diagnosis, presenting synchronously with a plasmacytoma. This is the first reported case of the simultaneous occurrence of an Askin tumor and a malignant hemopathy. The progression of the former and the remission of the plasmacytoma during chemotherapy were remarkable, since Askin tumor treatment shares drugs used for the treatment of plasma cell tumors. Given the infrequent presentation of these diseases in a young adult and the coexistence of two neoplasias characterized by typical chromosomal abnormalities, we consider the possibility of a genetic cancer susceptibility in our patient.

Adult↗

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