p53 protein alterations in adult astrocytic tumors and oligodendrogliomas. (17/77)

BACKGROUND: p53 is a tumor suppressor gene implicated in the genesis of a variety of malignancies including brain tumors. Overexpression of the p53 protein is often used as a surrogate indicator of alterations in the p53 gene. AIMS: In this study, data is presented on p53 protein expression in adult cases (>15 years of age) of astrocytic (n=152) and oligodendroglial (n=28) tumors of all grades. Of the astrocytic tumors, 86% were supratentorial in location while remaining 14% were located infratentorially - 8 in the the cerebellum and 13 in the brainstem. All the oligodendrogliomas were supratentorial. MATERIALS AND METHODS: p53 protein expression was evaluated on formalin-fixed paraffin-embedded sections using streptavidin biotin immunoperoxidase technique after high temperature antigen retrieval. RESULTS: Overall 52% of supratentorial astrocytic tumors showed p53 immunopositivity with no correlation to the histological grade. Thus, 58.8% of diffuse astrocytomas (WHO Grade II), 53.8% of anaplastic astrocytomas (WHO Grade III) and 50% of glioblastomas (WHO Grade IV) were p53 protein positive. In contrast, all the infratentorial tumors were p53 negative except for one brainstem glioblastoma. Similarly, pilocytic astrocytomas were uniformly p53 negative irrespective of the location. Among oligodendroglial tumors, the overall frequency of p53 immunopositivity was lower (only 28%), though a trend of positive correlation with the tumor grade was noted - 25% in Grade II and 31.5% in grade III (anaplastic oligodendroglioma). Interestingly, p53 labeling index (p53 LI) did not correlate with the histopathological grade in both astrocytic and oligodendroglial tumors. CONCLUSIONS: Thus, this study gives an insight into the genetic and hence biological heterogeneity of gliomas, not only between astrocytic tumors vs. oligodendrogliomas but also within astrocytic tumors with regard to their grade and location. With p53 gene therapy trials in progress, this will possibly have future therapeutic implications.  (+info)

Serial evaluation of academic and behavioral outcome after treatment with cranial radiation in childhood. (18/77)

PURPOSE: To evaluate academic and behavioral outcome in radiated survivors of posterior fossa (PF) tumors. PATIENTS AND METHODS: Fifty-three patients (36 males) treated for malignant PF tumors were seen for evaluation of academics and/or behavioral functioning. Forty-six patients were treated for medulloblastoma, and seven patients were treated for ependymoma. Fourteen patients were treated with reduced-dose cranial radiation, and 34 patients were treated with standard-dose cranial radiation (dose was not available for four patients). All patients received an additional boost to the PF. One patient was treated with PF radiation only. Standardized achievement tests and behavioral questionnaires were administered at different times after diagnosis for each child. First, the influence of demographic and medical variables on outcome was examined. Second, the rate of change in scores was determined using mixed model regression for patients seen for serial assessment. RESULTS: The presence of hydrocephalus was related to poorer academics, but outcome was not related to radiation dose, extent of surgery, or treatment with chemotherapy. Younger age predicted poor reading ability and lower parent rating of academic achievement. Children's performance declined for spelling, mathematics, and reading. Significant declines were also evident in parent and teacher's ratings of academic ability. Behavioral functioning was generally not related to medical and demographic variables, and few clinically significant problems in externalizing behavior were evident. Increases in social and attention problems emerged over time. CONCLUSION: Cranial radiation is associated with declines in academic ability, social skills, and attention. However, neither psychological distress nor behavior problems were a significant concern for this sample.  (+info)

MR Imaging of pial melanosis secondary to a posterior fossa melanotic ependymoma. (19/77)

A 36-year-old man presented with trouble speaking and bilateral progressive hearing loss. MR imaging and histopathologic results revealed a posterior fossa melanotic ependymoma. Pial surfaces appeared hyperintense on T1-weighted images and hypointense on T2-weighted images. Histopathologic examination revealed that tumor cells and interstitial spaces had abundant melanin accumulation. There was no evidence of hemosiderin in tumor cells and in interstitial spaces. Pial melanin accumulation secondary to a posterior fossa melanotic ependymoma explained our MR findings.  (+info)

Prenatal diagnosis of a giant congenital primary cerebral hemangiopericytoma. (20/77)

Congenital primary intracranial hemangiopericytomas are exceptionally rare tumors. We present a case of a fetus, with the prenatal sonogram at 33 weeks of gestation revealing a large cerebral tumor. Because of the enlarged head, a cesarean section was performed. The tumor was confirmed by postnatal ultrasound, magnetic resonance imaging (MRI) and biopsy. Elevated intracranial pressure and hemorrhage led to death on the 11th day. Autopsy revealed a 10x9 cm large inhomogeneous tumor located centrally, mainly in the posterior fossa. Histology showed a hypercellular and hypervascular tumor with extended necrosis and high mitotic rate. The tumor cells were positive for vimentin and CD34 antigens and negative for several neurological markers, desmin and CD31. The diagnosis of a congenital primary cerebral hemangiopericytoma was confirmed.  (+info)

Chromosomal imbalances in clear cell ependymomas. (21/77)

Clear cell ependymoma is a rare and diagnostically challenging subtype of ependymoma, whose genetic features are essentially unknown. We studied 13 clear cell ependymomas (five cases WHO grade II, eight cases WHO grade III) by comparative genomic hybridization (CGH). Chromosomal imbalances were found in 12/13 cases. The most common aberrations overall were +1q (38%), -9 (77%), -3 (31%), and -22q (23%). Clear cell ependymomas of WHO grade II were characterized by -9 (40%), whereas WHO grade III cases mainly showed +1q (63%), and +13q (25%), as well as -9 (100%), -3 (38%), and -22q (25%). In contrast to other ependymal tumors, clear cell ependymomas of WHO grade II showed fewer imbalances than WHO grade III samples (1.4 vs 3.5 per case). Although some of the implicated chromosomes have previously been shown to be involved in other ependymoma variants, the striking frequency of +1q, -9, and -3 suggests that aberrations differ between clear cell and other types of ependymomas, in particular, for loss of chromosome 9 which can be regarded as the molecular hallmark of clear cell ependymomas.  (+info)

Multicentric glioblastoma multiforme occurring in the supra- and the infratentorial regions--case report. (22/77)

A 74-year-old male was admitted because of severe headache, vertigo, and vomiting. A computed tomographic scan showed heterogeneously enhanced tumors in the supra- and the infratentorial regions, apparently attached to the cerebellar tentorium. He died 2 months after the onset despite external decompression and a ventriculo-peritoneal shunt. The autopsy showed both tumors were intra-axial and not attached to the dura mater including the cerebellar tentorium. The histological diagnosis of either tumor was glioblastoma multiforme. This case could be classified as multicentric gliomas. In the 23 reported cases, including our case, most died soon after the onset of symptoms. Some, however, with low grade tumors had a comparatively long life span after the onset. It is, therefore, important to investigate the histology of these tumors for correct prognosis.  (+info)

Intradural retroclival chordoma without bone involvement - case report. (23/77)

A 63-year-old, previously healthy man presented with a rare large intradural retroclival chordoma without bone involvement. Computed tomography showed that the tumor was completely intradural and did not involve the bone, as confirmed at intraoperative inspection. The tumor was totally excised via the anterior transpetrosal approach. Surgery is the most effective first-line treatment for patients with chordoma despite the typical extradural extension and bone destruction. Complete resection is feasible for intradural extraosseous chordoma because of the sharply circumscribed margins and absence of bone involvement. Specialized skull base techniques should be used instead of conventional surgical approaches for intradural skull base chordoma.  (+info)

Distinct genetic signatures among pilocytic astrocytomas relate to their brain region origin. (24/77)

Pilocytic astrocytomas (PAs) are the most common glioma in children. Whereas many PAs are slow-growing or clinically indolent, others exhibit more aggressive features with tumor recurrence and death. To identify genetic signatures that might predict PA clinical behavior, we did gene expression profiling on 41 primary PAs arising sporadically and in patients with neurofibromatosis type 1 (NF1). Whereas no expression signature was found that could discriminate clinically aggressive or recurrent tumors from more indolent cases, PAs arising in patients with NF1 did exhibit a unique gene expression pattern. In addition, we identified a gene expression signature that stratified PAs by location (supratentorial versus infratentorial). Lastly, we also identified a gene expression pattern common to PAs and normal mouse astrocytes and neural stem cells from these distinct brain regions as well as a gene expression pattern shared between PAs and another human glial tumor (ependymoma) arising supratentorially compared with those originating in the posterior fossa. These results suggest that glial tumors share an intrinsic, lineage-specific molecular signature that reflects the brain region in which their nonmalignant predecessors originated.  (+info)