Felice Giangaspero

International Society of Neuropathology‐Haarlem Consensus Guidelines for Nervous System Tumor Classification and Grading

Major discoveries in the biology of nervous system tumors have raised the question of how non‐histological data such as molecular information can be incorporated into the next World Health Organization (WHO) classification of central nervous system tumors. To address this question, a meeting of neuropathologists with expertise in molecular diagnosis was held in Haarlem, the Netherlands, under the sponsorship of the International Society of Neuropathology (ISN). Prior to the meeting, participants solicited input from clinical colleagues in diverse neuro‐oncological specialties. The present “white paper” catalogs the recommendations of the meeting, at which a consensus was reached that incorporation of molecular information into the next WHO classification should follow a set of provided “ISN‐Haarlem” guidelines. Salient recommendations include that (i) diagnostic entities should be defined as narrowly as possible to optimize interobserver reproducibility, clinicopathological predictions and therapeutic planning; (ii) diagnoses should be “layered” with histologic classification, WHO grade and molecular information listed below an “integrated diagnosis”; (iii) determinations should be made for each tumor entity as to whether molecular information is required, suggested or not needed for its definition; (iv) some pediatric entities should be separated from their adult counterparts; (v) input for guiding decisions regarding tumor classification should be solicited from experts in complementary disciplines of neuro‐oncology; and (iv) entity‐specific molecular testing and reporting formats should be followed in diagnostic reports. It is hoped that these guidelines will facilitate the forthcoming update of the fourth edition of the WHO classification of central nervous system tumors.

Growth, Subsequent Bleeding, and De Novo Appearance of Cerebral Cavernous Angiomas

In a series of 145 patients with brain cavernous angiomas treated at our hospital in the last 16 years, the angiomas of 18 patients exhibited aggressive biological behavior characterized by recurrent overt bleeding, growth, or de novo appearance. The cavernomas were in the cerebellum in three patients, in the brain stem in one, in the thalamus in four, in the caudate nucleus in two, in the diencephalon in one, and in the white matter of the cerebral hemispheres in seven. Three of these patients suffered from the familial or multiple form of the disease, two were pregnant, three had previously been irradiated for other tumors, and one had been treated by radiosurgery in the past. Overall, new cavernous malformations not previously shown were discovered in six patients. In 10 patients (3 male and 7 female) presenting with recurrent hemorrhages, the mean period of time between bleedings was 11 months (range, 1 wk-3 yr). Eleven patients were treated by definitive surgery, and seven were conservatively treated. One patient with a diencephalic cavernoma died from progressive hypothalamic dysfunction; three patients in the nonsurgical group had repeated symptoms and were left with additional neurological deficits. The outcome of the surgical group was the same (seven patients) or improved (four patients). Risk factors favoring an aggressive behavior included pregnancy, familial or multiple form of the disease, previous whole brain or stereotactic radiotherapy, incomplete removal, brain location, and associated venous malformation. The female preponderance (female to male ratio, 13:5) may also suggest some role of hormonal factors in influencing the biological behavior of cavernous malformations.

MicroRNA profiling in human medulloblastoma

Medulloblastoma is an aggressive brain malignancy with high incidence in childhood. Current treatment approaches have limited efficacy and severe side effects. Therefore, new risk‐adapted therapeutic strategies based on molecular classification are required. MicroRNA expression analysis has emerged as a powerful tool to identify candidate molecules playing an important role in a large number of malignancies. However, no data are yet available on human primary medulloblastomas. A high throughput microRNA expression profiles was performed in human primary medulloblastoma specimens to investigate microRNA involvement in medulloblastoma carcinogenesis. We identified specific microRNA expression patterns which distinguish medulloblastoma differing in histotypes (anaplastic, classic and desmoplastic), in molecular features (ErbB2 or c‐Myc overexpressing tumors) and in disease‐risk stratification. MicroRNAs expression profile clearly differentiates medulloblastoma from either adult or fetal normal cerebellar tissues. Only a few microRNAs displayed upregulated expression, while most of them were downregulated in tumor samples, suggesting a tumor growth‐inhibitory function. This property has been addressed for miR‐9 and miR‐125a, whose rescued expression promoted medulloblastoma cell growth arrest and apoptosis while targeting the proproliferative truncated TrkC isoform. In conclusion, misregulated microRNA expression profiles characterize human medulloblastomas, and may provide potential targets for novel therapeutic strategies.

Identification of Tumor-Specific Molecular Signatures in Intracranial Ependymoma and Association With Clinical Characteristics

PURPOSE To delineate clinically relevant molecular signatures of intracranial ependymoma. MATERIALS AND METHODS We analyzed 24 primary intracranial ependymomas. For genomic profiling, microarray-based comparative genomic hybridization (CGH) was used and results were validated by fluorescent in situ hybridization and loss of heterozygosity mapping. We performed gene expression profiling using microarrays, real-time quantitative reverse transcriptase polymerase chain reaction, and methylation analysis of selected genes. We applied class comparison analyses to compare both genomic and expression profiling data with clinical characteristics. RESULTS A variable number of genomic imbalances were detected by array CGH, revealing multiple regions of recurrent gain (including 2q23, 7p21, 12p, 13q21.1, and 20p12) and loss (including 5q31, 6q26, 7q36, 15q21.1, 16q24, 17p13.3, 19p13.2, and 22q13.3). An ependymoma-specific gene expression signature was characterized by the concurrent abnormal expression of developmental and differentiation pathways, including NOTCH and sonic hedgehog signaling. We identified specific differentially imbalanced genomic clones and gene expression signatures significantly associated with tumor location, patient age at disease onset, and retrospective risk for relapse. Integrated genomic and expression profiling allowed us to identify genes of which the expression is deregulated in intracranial ependymoma, such as overexpression of the putative proto-oncogene YAP1 (located at 11q22) and downregulation of the SULT4A1 gene (at 22q13.3). CONCLUSION The present exploratory molecular profiling study allowed us to refine previously reported intervals of genomic imbalance, to identify novel restricted regions of gain and loss, and to identify molecular signatures correlating with various clinical variables. Validation of these results on independent data sets represents the next step before translation into the clinical setting.

Capsaicin-induced apoptosis of glioma cells is mediated by TRPV1 vanilloid receptor and requires p38 MAPK activation.

We provide evidence on the expression of the transient receptor potential vanilloid type‐1 (TRPV1) by glioma cells, and its involvement in capsaicin (CPS)‐induced apoptosis. TRPV1 mRNA was identified by quantitative RT‐PCR in U373, U87, FC1 and FLS glioma cells, with U373 cells showing higher, and U87, FC1 and FLS cells lower TRPV1 expression as compared with normal human astrocytes. By flow cytometry we found that a substantial portion of both normal human astrocytes, and U87 and U373 glioma cells express TRPV1 protein. Moreover, we analyzed the expression of TRPV1 at mRNA and protein levels of glioma tissues with different grades. We found that TRPV1 gene and protein expression inversely correlated with glioma grading, with marked loss of TRPV1 expression in the majority of grade IV glioblastoma multiforme. We also described that CPS trigger apoptosis of U373, but not U87 cells. CPS‐induced apoptosis involved Ca2+ influx, p38 but not extracellular signal‐regulated mitogen‐activated protein kinase activation, phosphatidylserine exposure, mitochondrial permeability transmembrane pore opening and mitochondrial transmembrane potential dissipation, caspase 3 activation and oligonucleosomal DNA fragmentation. TRPV1 was functionally implicated in these events as they were markedly inhibited by the TRPV1 antagonist, capsazepine. Finally, p38 but not extracellular signal‐regulated protein kinase activation was required for TRPV1‐mediated CPS‐induced apoptosis of glioma cells.

Survival and Prognostic Factors of Early Childhood Medulloblastoma: An International Meta-Analysis

PURPOSE To assess the prognostic role of clinical parameters and histology in early childhood medulloblastoma. PATIENTS AND METHODS Clinical and histologic data from 270 children younger than age 5 years diagnosed with medulloblastoma between March 1987 and July 2004 and treated within prospective trials of five national study groups were centrally analyzed. RESULTS Two hundred sixty children with medulloblastoma and specified histologic subtype were eligible for analysis (median age, 1.89 years; median follow-up, 8.0 years). Rates for 8-year event-free survival (EFS) and overall survival (OS) were 55% and 76%, respectively, in 108 children with desmoplastic/nodular medulloblastoma (DNMB) or medulloblastoma with extensive nodularity (MBEN); 27% and 42%, respectively, in 145 children with classic medulloblastoma (CMB); and 14% and 14%, respectively, in seven children with large-cell/anaplastic (LC/A) medulloblastoma (P < .001). Histology (DNMB/MBEN: hazard ratio [HR], 0.44; 95% CI, 0.31 to 0.64; LC/A medulloblastoma: HR, 2.27; 95% CI, 0.95 to 5.54; P < .001 compared with CMB), incomplete resection and metastases (M0R1: HR, 1.86; 95% CI, 1.29 to 2.80; M+: HR, 2.28; 95% CI, 1.50 to 3.46; P < .001 compared with M0R0), and national group were independent prognostic factors for EFS, and OS. The HRs for OS ranged from 0.14 for localized M0 and DNMB/MBEN to 13.67 for metastatic LC/A medulloblastoma in different national groups. CONCLUSION Our results confirm the high frequency of desmoplastic variants of medulloblastomas in early childhood and histopathology as a strong independent prognostic factor. A controlled de-escalation of treatment may be appropriate for young children with DNMB and MBEN in future clinical trials.

large-cell Medulloblastomas : A Distinct Variant with Highly Aggressive Behavior

&NA; We present four cases of infantile cerebellar neoplasms composed of cells with large vesicular nuclei with prominent nucleoli. All four cases were strongly immunoreactive for synaptophysin, and one case showed immunoreactivity for neurofilaments. Filter hybridization for N‐myc and c‐myc oncogenes showed a 27‐fold c‐myc amplification in one case. The cytogenetic analysis in this case showed Double‐Minutes and isochromosome 17q. An intracerebral xenograft in nude mice obtained from one such tumor showed a similar morphology to that of the original tumor as well as strong immunoreactivity for synaptophysin and neurofilaments. All the neoplasms were characterized by highly aggressive behavior leading to early cerebrospinal fluid dissemination despite radiotherapy and chemotherapy. We conclude that large‐cell medulloblastoma represents a distinct and more aggressive variant of medulloblastoma that requires more aggressive therapy.

Nonsense Mutation and Inactivation of SMARCA4 (BRG1) in an Atypical Teratoid/Rhabdoid Tumor Showing Retained SMARCB1 (INI1) Expression

Atypical teratoid/rhabdoid tumors (AT/RTs) are highly aggressive brain tumors of early childhood poorly responding to therapy. The majority of cases show inactivation of SMARCB1 (INI1, hSNF5, BAF47), a core member of the adenosine triphosphate (ATP)-dependent SWI/SNF chromatin-remodeling complex. We here report the case of a supratentorial AT/RT in a 9-month-old boy, which showed retained SMARCB1 staining on immunohistochemistry and lacked genetic alterations of SMARCB1. Instead, the tumor showed loss of protein expression of another SWI/SNF chromatin-remodeling complex member, the ATPase subunit SMARCA4 (BRG1) due to a homozygous SMARCA4 mutation [c.2032C>T (p.Q678X)]. Our findings highlight the role of SMARCA4 in the pathogenesis of SMARCB1-positive AT/RT and the usefulness of antibodies directed against SMARCA4 in this diagnostic setting.

Ependymomas: A clinicopathologic study

Since 1924, when ependymomas were first classified as a distinctive glial neoplasm by Bailey, much has been published concerning these tumors, but there are important points of interest that are still not clear. In order to study more fully the clinical and pathologic characteristics of the ependymoma, we identified 62 patients with histologically proven neoplasms. Twenty-two were supratentorial, 21 were infratentorial, and 19 were intramedullary spinal cord tumors. These groups had mean ages of 17, 7, and 41 years, respectively, at the time of first symptoms. The presenting and accompanying symptoms were related to location and included headaches, nausea, visual changes, hemiparesis, and neck, back, and radicular pain. Neurological signs included papilledema, nystagmus, gait disturbance, cranial nerve palsies, altered mental status, paraparesis, and sensory dysfunction. Radiologic modalities of particular importance included computed tomography and myelography. Surgery and radiation therapy were the primary treatment modalities with median survival times from first symptoms being 92, 36, and 117 months for the above groups, respectively. Based on computer-generated survival curves, several characteristics significantly affected survival. These included tumor site, age, and neuraxis metastases. In patients with supratentorial tumors, cranial nerve palsies, microcystic changes, and mitotic figures were important, while in patients with infratentorial tumors, widened sutures, increased head circumference, age, epithelial features, and subependymal features significantly affected survival. Patients who had complete gross resection of a spinal cord tumor had no recurrences or mortality.

Growth fraction in human brain tumors defined by the monoclonal antibody Ki-67.

SummaryThe monoclonal antibody Ki-67, which reacts with cells in the active part of the cell cycle, was used to evaluate immunocytochemically the growth fraction in 22 primary brain neoplasms. The percentage of labelled cells reflected the histological grade of malignancy of each neoplasms. High percentage of Ki-67-positive cells were observed in one choroid plexus carcinoma (60%), one primary melanoma of meninges (40%), three medulloblastomas (40%–50%), one anaplastic astrocytoma and six glioblastomas (10%–40%). One ependymoma had 7% positive cells. Rare positive cells (1%) were present in one pilocytic astrocytoma and one ganglioglioma. Except one negative case, the meningiomas (five cases) had values of positivity ranging from 1% to 6%. Two acoustic schwannomas were negative. These results suggest that immunocytochemical staining with the Ki-67 may be a useful method for measuring the growth fraction in brain neoplasms.