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    OBJECTIVE Uniform cells with round, regular nuclei characterize the typical histologic aspect of medulloblastoma. Enlargement of nuclei distinguishes the large-cell medulloblastoma variant and is associated with a poor prognosis in pediatric medulloblastomas. The aim of the present study was to compare the size of nuclei between pediatric and adult medulloblastomas by a morphometric analysis. MATERIAL AND METHODS In 79 neurosurgical specimens of cerebellar medulloblastomas, the maximum nuclear diameter of the largest nuclei was measured. Measurements were performed with a digital-image analysis system. The measure of the maximum diameter was chosen in order to reduce the split cell error. RESULTS The difference between the mean values in children and adults was statistically significant (p = 0,001). The distribution of maximum values measured in each case had two distinct peaks in the two age groups, in 3.5% of adult cases and in more than 30% of pediatric cases the maximum nuclear size was superior to 12 microm. CONCLUSIONS The present results show that nuclei of tumor cells in pediatric medulloblastomas are larger than those in adult medulloblastomas and confirm that the phenotype of medulloblastoma is different in the two age groups. Distinct genetic events can, thus, underlie medulloblastoma in childhood and adult age, the prognostic role of genetic variables can differ by age.
    Age groups
    Citations (3)
    Medulloblastoma is the most frequent childhood brain tumor. Medulloblastoma affects the cerebellum, the brain region that regulates motor coordination and is also involved in certain cognitive functions. Medulloblastoma is a heterogeneous tumor, and recent advances in high-throughput genomic techniques have allowed medulloblastoma to be classified into four molecularly distinct subgroups: the SHH-group, WNT-group, group 3, and group 4 medulloblastoma.
    Brain tumor
    UNLABELLED Medulloblastoma, a primitive neuroectodermal tumor growing in cerebellum, is one of the most sensitive to radiation therapy childhood brain tumors, therefore, this method of treatments is justly considered to be the standard for the treatment of medulloblastoma. The outcome of this malignant brain tumor differs in standard and high-risk groups of patients. The aim of the work was to evaluate the survival rate for children with medulloblastoma according to two risk groups. PATIENTS AND METHODS Eighteen patients aged from 3 to 18 years with histological proven medulloblastoma treated with standard craniospinal and additional posterior fossa radiotherapy were investigated in our study. Nine patients with disseminated and partial removed medulloblastoma were assigned to the high-risk group and other 9 patients with local ant totally removed medulloblastoma were allocated to the standard risk group. RESULTS Radiological response of medulloblastoma to the radiation therapy was observed in 15 (83.3%) out of 18 patients: complete radiological response was observed in 6 (67%) out of 9 standard-risk patients and in only 1 (11.1%) out of 9 high-risk patients (p 0.05). The mean time to progression for all patients was 18.2 months: 28.9 months in standard and 7.4 months in high-risk group (p=0.02). The overall survival for all investigated patients was 25.8 months: 37.2 and 14.3 months in the standard and high-risk groups, respectively (p=0.01). Five years progression-free and overall survival rate for all patients was 16.7%: 0% in the high-risk group and 33.3 % in the standard-risk group (p>0.05). CONCLUSION In our study the difference in survival rate between standard and high-risk patients with medulloblastoma was shown. We observed a statistically significant longer time to progression and better overall survival in the standard-risk group. However, we did not find any significant differences in other survival indices (response, relapse rates, mortality, five years progression- free and overall survival) between those two risk groups.
    Brain tumor
    Citations (5)
    Objective: To investigate the CT,MRI and pathological examinations of the medulloblastoma in children,in order to improve the accuracy in early diagnosis,and provide reliable data for the clinic treatment before and after operation.Materials and Methods: Fifteen cases of pediatric medulloblastoma,with their age ranging from four to eleven years old,were provided by operation and pathological examination.Results: Nine cases of medulloblastoma were diagnosed by CT.Fourteen cases of medulloblastoma were diagnosed by MRI.One case of medulloblastoma or ependymoma were diagnosed.Fifteen cases of pediatric medulloblastoma were confirmed by pathological examination.Conclusion: MRI was superior to CT in determining the location and diagnosis of medulloblastoma.The early discovery and early treatment are the keys to prolonging the survial of pediatric patients with medulloblastoma~([1]).
    Ependymoma
    Citations (0)
    A case of a melanotic cerebellar tumor in a three year old child is described. The tumor has a close histological resemblance to the melanotic neuroectodermal tumor of infancy occurring extracranially. Despite this, the histological appearance, the site of involvement, the age incidence, and the malignant behavior of the tumor are similar to that of the usual medulloblastoma. Furthermore, the predominating cellular element of the tumor is indistinguishable from that of the medulloblastoma. The melanotic cerebellar tumor is, therefore, considered to be a variant of medulloblastoma and is designated as melanotic medulloblastoma.
    Medulloblastoma is a malignant, invasive embryonal tumor of the cerebellum with preferential manifestation in children, predominantly neuronal differentiation and an inherent tendency to metastasize via CSF pathways. In this review we present an overview of the clinicopathological aspects of medulloblastoma and the recent developments in the biology and genetics of these embryonal brain tumors. Increased knowledge of the signaling pathways that play a role in normal cerebellum development and tumor formation may lead to new therapeutic approaches resulting in a higher cure rate and a better quality of life of medulloblastoma patients.
    Brain tumor
    Citations (1)
    Aberrant expression of protein arginine methyltransferases (PRMTs) has been implicated in a number of brain tumors, but the role of PRMT1 in medulloblastoma, the most common malignant pediatric brain tumor, remains unexplored
    Medulloblastoma is one of the most common pediatric malignant brain tumors. Its understanding and treatment have advanced rapidly over the decade, with the identification of four distinct molecular groups. In contrast, adult medulloblastoma is a rare entity that accounts for <1% of adult central nervous system tumors, and is understudied in both its genetic landscape and clinical management. Adult medulloblastomas demonstrate many differences from pediatric medulloblastomas that are relevant to clinicians and biologists. Unlike its pediatric counterpart, adult medulloblastomas are typically located laterally in the cerebellum, are seldom metastatic, and commonly relapse beyond 5 years. The distribution and survival outcomes of molecular groups in adult medulloblastoma differ from those in pediatric medulloblastoma, with the sonic hedgehog-activated group being the predominant and most well-studied group in adults. Adult medulloblastomas also exhibit cytogenetic and mutational characteristics unique to this age group, such as the high frequency of telomerase reverse transcriptase promoter mutations and the paucity of MYC and MYCN amplifications. Clinical trials for adult medulloblastoma need to take into account the clinical and biological differences between adult and pediatric medulloblastomas, for example through the use of smoothened inhibitors in adult SHH medulloblastomas to lower the toxicities resulting from direct adoption of pediatric chemotherapeutic regimens. This review summarizes the clinical characteristics, molecular groups, genetic features, and treatment of adult medulloblastoma, with a focus on its differences from pediatric medulloblastoma.