Giant Atypical Intraventricular Meningioma in a Child.

We present the case of a 14-year-old boy with a giant tumor of the lateral ventricle. The patient was operated upon. Histopathology showed the presence of an atypical meningioma. Postoperative imaging confirmed the complete tumor excision. Meningiomas although frequent in adults are rare in children. Intraventricular meningiomas are exceedingly rare. Complete surgical excision should be the goal of treatment and is usually associated with a favorable outcome.

Proteomic studies of pediatric medulloblastoma tumors with 17p deletion.

CNS tumors are the leading cause of cancer-related death in children. Medulloblastoma is the commonest pediatric CNS malignancy, wherein, despite multimodal therapy with surgery, radiation, and chemotherapy, 5 year survival rates merely approach 60%. Until present, gene expression and cytogenetic studies have produced contradicting findings regarding the molecular background of the specific disease. Through integration of genomics, bioinformatics, and proteomics, the current study aims to shed light at the proteomic-related molecular events responsible for MBL pathophysiology, as well as to provide molecular/protein/pathway answers concerning tumor-onset. Experiments were performed on tissues collected at surgery. With 17p loss being the commonest chromosomal aberrance observed in our sample set, array-CGH were employed to first distinguish for 17p-positive cases. 2-DE coupled to mass spectrometry identification exposed the MBL-specific protein profile. Protein profiles of malignant tissues were compared against profiles of normal cerebellar tissues, and quantitative protein differences were determined. Bioinformatics, functional and database analyses, characterization, and subnetwork profiling generated information on MBL protein interactions. Key molecules of the PI3K/mTOR signaling network were identified via the techniques applied herein. Among the findings IGF2, PI3K, Rictor, MAPKAP1, S6K1, 4EBP1, and ELF4A, as part of the IGF network (implicating PI3K/mTOR), were founded to be deregulated.

The Role of Fast Cell Cycle Analysis in Pediatric Brain Tumors.

Cell cycle analysis by flow cytometry has not been adequately studied in pediatric brain tumors. We investigated the value of a modified rapid (within 6 min) cell cycle analysis protocol for the characterization of malignancy of pediatric brain tumors and for the differentiation of neoplastic from nonneoplastic tissue for possible intraoperative application. We retrospectively studied brain tumor specimens from patients treated at our institute over a 5-year period. All tumor samples were histopathologically verified before flow-cytometric analysis. The histopathological examination of permanent tissue sections was the gold standard. There were 68 brain tumor cases. All tumors had significantly lower G0/G1 and significantly higher S phase and mitosis fractions than normal brain tissue. Furthermore low-grade tumors could be differentiated from high-grade tumors. DNA aneuploidy was detected in 35 tumors. A correlation between S phase fraction and Ki-67 index was found in medulloblastomas and anaplastic ependymomas. Rapid cell cycle analysis by flow cytometry is a promising method for the identification of neoplastic tissue intraoperatively. Low-grade tumors could be differentiated from high-grade tumors. Thus, cell cycle analysis can be a valuable adjunct to the histopathological evaluation of pediatric brain tumors, whereas its intraoperative application warrants further investigation.

BRAF alterations in pediatric low grade gliomas and mixed neuronal-glial tumors.

Low grade astrocytomas are the most common brain tumor in children. Recent studies have identified alterations in the BRAF serine/threonine kinase gene that result in mitogen activated protein kinase pathway activation. Herewith, we investigated the genetic changes of BRAF in pediatric low grade gliomas and their relation to pathological findings and Ki-67 proliferation index. The results showed gene fusions between KIAA1549 and BRAF in 66.7 % of tumors. The majority involved the KIAA1549-BRAF exon 16-exon 9 variant. Fusion junction between KIAA1549 exon 15 and BRAF exon 9 was found in five tumors, in which the myxoid component was the predominant. This has not been previously reported. No significant correlation was found between specific KIAA1549 and BRAF fusion junctions and Ki-67 index. All of the samples included in this study were tested for the presence of the BRAF(V600E) mutation, and no positive sample was found.

Immunohistochemical expression of cell-cycle regulators in pediatric embryonal brain tumors.

Embryonal tumors constitute the most common malignant brain tumor group in children. Experimental results indicate that genes involved in cell cycle and signal transduction are deregulated in medulloblastoma (MB) and atypical teratoid/rhabdoid tumors (AT/RT). The cell cycle is regulated by protein complexes composed of a regulatory subunit called Cyclin and a catalytic domain named Cyclin-dependent kinase (CDK). Cyclins and CDKs are in turn regulated by cyclin-dependent kinase inhibitors (CDKI) which inhibit cell-cycle progression. Cyclins D and Cyclin E are important for the passage of cells through G1 to S phase. P-27, a member of the universal CDKI family, is important in regulating the G1/S transition. Thus, the purpose of this study was to investigate the expression of p-27, Cyclin D3, and Cyclin E, and their possible prognostic significance in pediatric embryonal brain tumors. We retrospectively evaluated 51 children with embryonal tumors that were treated surgically in our institute. All patients had regular follow up examinations. The streptavidin-biotin HRP method was performed on paraffin sections for detection of p-27, Cyclin D3, and Cyclin E. There were 42 cases of MB and nine cases of AT/RT. Cyclin D3 expression was detected in 11/42 MB and 3/9 AT/RT patients. Cyclin E expression was detected in 28/42 MB and 8/9 AT/RT patients. High expression of Ki-67 (>50 %) and p-27 (>50 %) was observed in 23.8-73.8 % of MB patients. Combined high Ki-67 and p-27 expression was observed in 21.4 % cases of MB. In these cases there was expression of Cyclin E in 88.8 % and Cyclin D3 in 22.2 % of MB. No significant correlation was found between Ki-67 and p-27, Cyclin D3, and E. No correlation was found between Cyclin D3, Cyclin E, p-27, and overall survival. Increased p-27 and Cyclin E expression was detected in a substantial number of MB patients and in nearly all AT/RT patients. Further studies on a larger number of patients are needed to clarify a possible correlation of p-27 and Cyclin E with tumor behavior.

Medulloblastoma in a child with fragile X syndrome.

Fragile X syndrome is the most common cause of inherited intellectual impairment and has been associated with decreased incidence of cancer. We present the case of an 11-year-old boy with a diagnosis of fragile X syndrome who presented with gait imbalance, headache, and episodes of vomiting. Radiological investigation revealed the presence of a posterior fossa tumor. The patient was operated upon and the tumor proved to be a medulloblastoma (MB). To the best of our knowledge this is the first reported case of MB in a child with fragile X syndrome.

Tumors of central and peripheral nervous system associated with inherited genetic syndromes.

There are several genetic syndromes that predispose to the development of tumors of the nervous system. In the present study, we provide a review of the tumors that are associated with neurofibromatosis type 1, neurofibromatosis type 2, tuberous sclerosis complex, von Hippel-Lindau disease, Li-Fraumeni syndrome, Cowden disease, Turcot syndrome, nevoid basal cell carcinoma syndrome (Gorlin syndrome) and rhabdoid predisposition syndrome, which are the most common.

Proteomics studies of childhood pilocytic astrocytoma.

Childhood pilocytic astrocytoma is the most frequent brain tumor affecting children. Proteomics analysis is currently considered a powerful tool for global evaluation of protein expression and has been widely applied in the field of cancer research. In the present study, a series of proteomics, genomics, and bioinformatics approaches were employed to identify, classify and characterize the proteome content of low-grade brain tumors as it appears in early childhood. Through bioinformatics database construction, protein profiles generated from pathological tissue samples were compared against profiles of normal brain tissues. Additionally, experiments of comparative genomic hybridization arrays were employed to monitor for genetic aberrations and sustain the interpretation and evaluation of the proteomic data. The current study confirms the dominance of MAPK pathway for the childhood pilocytic astrocytoma occurrence and novel findings regarding the ERK-2 expression are reported.

Achondroplasia with synostosis of multiple sutures.

We report for the second time on a case of achondroplasia with synostosis of multiple sutures. The most common mutation for achondroplasia (FGFR3 Gly380Arg, resulting in 1138G>A) was identified. Imaging studies disclosed complex craniosynostosis and neurosurgical intervention was carried out, particularly for posterior plagiocephaly.

Prognostic significance of cyclin A and B1 in pediatric embryonal tumors.

Embryonal tumors constitute the most common malignant brain tumor group in children. Although patient prognosis has been substantially improved over recent decades, identification of prognostic markers would be of obvious significance. In the present study we evaluated the prognostic significance of cyclin A and B1 in correlation with Ki-67 index in pediatric embryonal tumors. We retrospectively evaluated 53 children with embryonic tumors who were treated surgically in our institute. All patients had regular follow-up examinations. The streptavidin-biotin-horseradish peroxidase (HRP) method was performed on paraffin sections for detection of Ki-67/MIB-1, and cyclin A and B1. There were 42 cases of medulloblastoma (MB), 9 cases of atypical teratoid/rhabdoid tumor (AT/RT), and 2 cases of supratentorial primitive neuroectodermal tumor (PNET). In MB patients, Ki-67 index >50% was associated with worse survival (P = 0.003). Cyclin A index >40% was associated with significantly poorer survival (P = 0.023). Patients with cyclin B1 index >15% exhibited a trend towards poorer survival (P = 0.068). On multivariate analysis, only Ki-67 index was identified as a factor with independent prognostic power. In AT/RT and PNET, there was high expression of Ki-67 and variable expression of cyclin A and B1. Apart from Ki-67 index, cyclin A may have a prognostic role. Study of the above indices at diagnosis could alter or intensify treatment methods, so as to improve disease outcome. There is obviously a need for future studies with larger number of patients to confirm our preliminary observations.

Cranial Ewing's sarcoma in children.

Ewing's sarcoma is a highly malignant neoplasm of bones which accounts for the 10% of primary bone malignancies. Primary Ewing's sarcoma of skull vault is very rare and constitutes 1-6% of all Ewing's sarcomas. We present a case of a primary and a radiation-induced skull Ewing's sarcoma. The symptoms, neuroimaging findings and the treatment for these cases are reviewed. Both children were operated with favorable outcome.

Meningioangiomatosis in a 5-year-old boy presenting with intractable seizures.

A 5-year-old boy with a history of epilepsy underwent brain magnetic resonance imaging (MRI) because of an increase in seizure frequency. Brain MRI demonstrated a left frontal lesion. The patient was operated upon, and gross total excision was performed. The histological diagnosis was meningioangiomatosis. On follow-up examination 10 years later, the patient was free of seizures and without any evidence of tumor recurrence. Meningioangiomatosis is a rare benign hamartomatous lesion that is associated with seizures. Complete excision is associated with favorable long-term outcome. The novelty of the present case is the young age of the child at presentation and the curative role of surgery considering the long-term follow-up.

Prognostic significance of angiogenesis in relation to Ki-67, p-53, p-27, and bcl-2 expression in embryonal tumors.

AIM: We investigated the angiogenesis and density of newly formed blood vessels in embryonal tumors in relation to Ki-67, bcl-2, p-53 and p-27 expression. METHODS: Forty-five children with embryonal tumors were enrolled in the study. Forty patients had a medulloblastoma (MB) and 5 patients had atypical teratoid/rhabdoid tumor (AT/RT). RESULTS: In MB, the 5-year PFS and OS was 62.5 and 70%, respectively. Patients with Ki-67 index >50%, bcl-2 index >30% and higher density of new vessels were associated with worse survival. In the multivariate analysis, Ki-67 index was identified as a factor with independent prognostic power. In AT/RTs, high density of new vessels (>25 HRF) was observed in 3 patients and Ki-67 index over 25% was found in 4 patients. CONCLUSION: Increased Ki-67, bcl-2 and density of new vessels are of prognostic value for the disease outcome in MB.

Cerebral abnormalities in infants with myelomeningocele.

BACKGROUND AND PURPOSE: We evaluated brain abnormalities associated with myelomeningocele in infants. MATERIAL AND METHODS: Between June 1995 and June 2008, 42 patients with myelomeningocele were treated in our hospital. Only 24 patients (13 males, 11 females, mean age 1.5 months, range 1 day - 11 months) were evaluated by both spinal and brain magnetic resonance imaging (MRI) and were enrolled in the study. RESULTS: Brain MRI revealed: hydrocephalus in 21 (87.5%) patients, all of whom required immediate shunting. Total agenesis of the corpus callosum was observed in 2 (8.3%) patients, partial agenesis was seen in 4 (17%) patients and 8 (34%) patients had dysplasia of the corpus callosum. Absence of the septum pellucidum was observed in 2 (8%) patients. Widening of the interhemispheric fissure and colpocephaly were noted in 10 (41%) and in 3 (12%) patients, respectively. Abnormal white matter maturation was observed in 2 (8%) patients. Small posterior fossa was observed in 18 (74%) patients, Chiari malformation in 16 (67%) patients, cerebellar and brain stem hypoplasia in 3 (12%) and 7 (30%) patients, respectively. CONCLUSIONS: MRI examination of the myelomeningocele site is not sufficient. Clinicians should consider obtaining imaging studies of the entire neuraxis in patients with myelomeningocele.

Alpha-fetoprotein secretion in a craniopharyngioma. Are craniopharyngiomas part of the germ cell tumor family?

A 14-months-old girl was admitted to our hospital because of excessive irritability and abnormal eye movements over the last two months. Brain CT and MRI revealed a suprasellar cystic and partially solid mass with calcifications. The laboratory investigation revealed increased serum levels of AFP. These findings were suggestive for a brain germ cell tumor. Therefore, systemic chemotherapy was started. After two courses there was a reduction in the levels of AFP but the tumor size remained unchanged. Subtotal tumor excision was performed that revealed the presence of a craniopharyngioma. One month later there was enlargement of the cystic part of the tumor, while serum AFP was elevated. The child received again systemic chemotherapy and placement of a reservoir into the cystic part of the tumor. Analysis of the intracystic flouid revealed the presence of beta-HCG and AFP. Following that the patient received brachytherapy with intracavity yttrium placement. Three months later repeated MRI showed a decrease in the size of the cystic part, while the solid part remained unchanged. Thus, the solid part was treated by radiosurgery. One year later the patient was stable but with complete loss of vision. These observations support the theory of a germ cell tumor family, in which craniopharyngioma and germ cell tumor present the two sides of the same entity, while between them a wide variety of tumors, with variable type of secretion of AFP and/or beta-HCG, may exist.

Expression of epidermal growth factor receptor and HER-2 in pediatric embryonal brain tumors.

BACKGROUND/AIMS: Medulloblastomas (MBs), atypical teratoid rhabdoid tumors (AT/RTs) and central nervous system primitive neuroectodermal tumors (PNETs) are aggressive embryonal brain neoplasms in children with overlapping histological features but with different pathogenetic pathways. We set out to evaluate the role of epidermal growth factor receptor (EGFR), HER-2, Ki-67 and p53 in embryonal tumors. MATERIAL AND METHODS: We retrospectively evaluated 36 children with embryonic tumors (27 MBs, 7 AT/RTs and 2 supratentorial PNETs). The immunohistochemical expression of EGFR and HER-2 was correlated to histology, expression of the Ki-67/MIB-1 proliferative index, p53 tumor suppressor oncoprotein and prognosis. RESULTS: High expression of Ki-67 was observed in all MBs being particularly increased (> 50%) in 8 cases, while p53 protein was detected in 25/27 MBs showing a high expression in 16 cases. EGFR and HER-2 expression was observed in 10/27 and 17/27 MBs, respectively. High Ki-67/MIB-1 and p53 expression was revealed in all AT/RTs and PNETs, while EGFR and HER-2 were detected in 3/7 and 6/7 AT/RTs, respectively. The 5-year progression-free survival and overall survival were 55.5 and 69.2%, respectively. In MBs, the univariate analysis revealed that the Ki-67 index and male gender were both at a significant level related to the survival of the patient. In multivariate analysis, the Ki-67 index was the only independent predictive variable. CONCLUSIONS: The Ki-67 index was identified as a factor with independent prognostic power. EGFR and HER-2 expression is variable in embryonal tumors. HER-2 expression, in a considerable number of MBs and AT/RTs, suggests that HER-2 may be implicated in their pathogenesis representing a potential target for novel therapies.

Diagnosis and management of cephaloceles.

Cephaloceles are rare neural tube defects. In this study, we retrospectively reviewed the charts of all patients with cephaloceles who underwent surgical treatment in our institute for a 14-year period, between January 1995 and January 2009. There were 27 children (11 boys and 16 girls; mean age, 7.5 mo; range, 1 d to 7 y). Seventeen encephaloceles were occipital; 5, parietal; 2, ethmoidal; 1, frontoethmoidal; 1, nasoethmoidal; and 1, sphenoethmoidal. The mean size of sac was 3 cm, although 2 cases of giant occipital encephaloceles were observed. In 19 cases (70%), the sac contained gliotic brain (encephaloceles) that was excised. All patients were operated on in 1 surgical procedure. Hydrocephalus was found in 16 patients and treated with a ventriculoperitoneal shunt insertion. Postoperatively, there was no neurologic deficit or death. After a mean follow-up period of 7.2 years (range, 6 mo to 11.5 y), all patients were in good condition. In conclusion, occipital cephaloceles are more frequently encountered and are usually associated with hydrocephalus. Surgery should be performed as early as possible and only after careful preoperative planning especially for the anterior cephaloceles.

Surgical management of brain cavernomas in children.

BACKGROUND: Cavernous hemangiomas are benign vascular hamartomas caused by developmental malformations of the vascular bed. They can be found in 0.3-0.7% of the population, whereas one fourth of these lesions occur in children. METHODS: In the present study, we report on 16 cases of cavernomas surgically treated in our institute. From each patient's file, the age, sex, lesion location, symptoms and follow-up were analyzed. RESULTS: The most commonly presenting symptom was epilepsy. Radiological signs of acute hemorrhage were observed in 3 cases. Three children had multiple cavernomas. The parietal lobe was the most common site of occurrence, whereas only 2 cavernomas were infratentorial. There was no operative mortality. Postoperatively, there was no additional neurological deficit, and all patients gradually improved. In a case of pontine cavernoma, there was a need for reoperation due to rebleeding. CONCLUSION: With the improvement of microsurgical techniques and modern neuroimaging, nearly all cavernomas can be safely removed. Total resection is associated with patients' clinical improvement and seizure control.