Posterior fossa tumor in children

Primary brain tumors are the most common solid neoplasms of childhood, representing 20% of all pediatric tumors. The best current estimates place the incidence between 2.76 and 4.28/100,000 children per year. Compared with brain tumors in adults, a much higher percentage of pediatric brain tumors arise in the posterior fossa. Infratentorial tumors comprise as many as two thirds of all pediatric brain tumors in some large series. Tumor types that most often occur in the posterior fossa include medulloblastoma, ependymoma, cerebellar astrocytoma and brainstem glioma. All pediatric cases of posterior fossa tumor that were considered for surgery from 1981 to 2011 were selected and the demographic data including age, gender and tumor characteristics along with the location and pathological diagnosis were recorded. The surgical outcomes were assessed according to pathological diagnosis. Our series consisted of 84 patients [52 males, 32 females]. Cerebellar symptoms were the most common cause of presentation [80.9%] followed by headache [73.8%] and vomiting [38.1%]. The most common histology was medulloblastoma [42.8%] followed by cerebellar astrocytoma [28.6%], ependymoma [14.3%], brainstem glioma [7.2%] and miscellaneous pathologies [e.g., dermoid, and tuberculoma] [7.2%]. The diagnosis of brain tumors in the general pediatric population remains challenging. Most symptomatic children require several visits to a physician before the correct diagnosis is made. These patients are often misdiagnosed for gastrointestinal disorders. Greater understanding of the clinical presentation of these tumors and judicious use of modern neuroimaging techniques should lead to more efficacious therapies

Histological findings of posterior fossa tumors in children

To find out different histopathological types of posterior fossa tumors in children. This Descriptive study was carried out in Department of Neuro surgery Govt. Lady Reading Hospital Peshawar from June 2003 to May 2008, All patients with posterior fossa tumors under 14 years were included in the study. Patient with brainstem glioma, posterior fossa abscesses and pineal tumors were excluded. A total of 117 patients were included. There were 80 male and 37 female with sex ratio of 2.1:1 with age range from 6 months to 14 years with mean age of 8.9 years and SD + 5.4. Computerized Axial Tomography / Magnetic Resonance Imaging of the brain were done for establishing diagnosis. Different surgical procedures for tumor removal were performed and specimen was sent for histopathological study in all operative cases. Out of 117 patients Medulloblastoma was seen in 38 [32.7%], Ependymoma in 23 [19.65%] Astrocystoma in 25 [21.36%], Hemangioblastoma in 19 [16.23%] Tuberculoma in 4 [3.41%] Meningioma in 2 [1.7%] and dermoid and epidermoid cyst in 3 cases each [2.56%]. Medulloblastoma was seen commonly between 6-10 years in 22 [18.8%] patients. Astrocystoma between 6 -10 years in 12[10.25%] patients. Ependymoma is common below 5 years in 17[14.5%] patients. Hemangioblastoma between 6-10 years in 15 [12.82%] patients, tuberculoma in 3[2.56%] patients in 6 -10 years of age. Medulloblastoma and Pilocytic Astrocystoma and Hemangioblastoma are common tumors between 6-10 years of age and Ependymoma is common below 5 years. Tuberculoma is also tumor mimicking condition occurring in posterior fossa

Meduloblastoma: correlação entre ressonância magnética convencional, difusão e espectroscopia de prótons / Medulloblastoma: correlation among findings of conventional magnetic resonance imaging, diffusion-weighted imaging and proton magnetic resonance spectroscopy", "_i": "en

OBJETIVO: Correlacionar os achados de ressonância magnética convencional, difusão e espectroscopia de prótons nos meduloblastomas, e compará-los aos dados da literatura. MATERIAIS E MÉTODOS: Análise retrospectivade exames de ressonância magnética pré-operatórios de nove pacientes na faixa pediátrica com diagnóstico histológico de meduloblastoma (oito desmoplásicos e um de células gigantes). Foram considerados dados demográficos e características do tumor como localização, característica morfológica, intensidade de sinal, realce, disseminação e achados na difusão e espectroscopia. RESULTADOS: Na maioria dos casos os tumores apresentaram epicentro no vermis cerebelar (77,8%), sendo predominantemente sólido (88,9%), com hipossinal nas seqüências ponderadas em T1 e iso/hipersinal nas seqüências ponderadas em T2 e FLAIR, realce heterogêneo (100%), sinais de disseminação/extensão tumoral (77,8%) e restrição à movimentação das moléculas de água (100%). A espectroscopia de prótons pela técnica STEAM (n = 6) demonstrou redução da relação Naa/Cr (83,3%) e aumento de Co/Cr (100%) e mI/Cr (66,7%), e pela técnica PRESS (n = 7) evidenciou pico de lactato (57,1%). CONCLUSÃO: O conjunto dos achados macroscópicosobtidos pela ressonância magnética, somado às características bioquímicas dos meduloblastomas, têm sido úteis na tentativa de diferenciação entre os principais tumores da fossa posterior.

OBJECTIVE: To correlate imaging findings of medulloblastomas at conventional magnetic resonance imaging, diffusion-weighted imaging and proton magnetic resonance spectroscopy, comparing them with data in the literature. MATERIALS AND METHODS: Preoperative magnetic resonance imaging studies of nine pediatric patients with histologically confirmed medulloblastomas (eight desmoplastic medulloblastoma, and one giant cell medulloblastoma) were retrospectively reviewed, considering demographics as well as tumorscharacteristics such as localization, morphology, signal intensity, contrast-enhancement, dissemination, anddiffusion-weighted imaging and spectroscopy findings. RESULTS: In most of cases the tumors were centeredin the cerebellar vermis (77.8%), predominantly solid (88.9%), hypointense on T1-weighted images andintermediate/hyperintense on T2-FLAIR-weighted images, with heterogeneous enhancement (100%), tumor dissemination/extension (77.8%) and limited water molecule mobility (100%). Proton spectroscopy acquiredwith STEAM technique (n = 6) demonstrated decreased Naa/Cr ratio (83.3%) and increased Co/Cr (100%)and mI/Cr (66.7%) ratios; and with PRESS technique (n = 7) demonstrated lactate peak (57.1%). CONCLUSION: Macroscopic magnetic resonance imaging findings in association with biochemical features of medulloblastomas have been useful in the differentiation among the most frequent posterior fossa tumors. Keywords: Medulloblastoma; Infratentorial neoplasms; Pediatric brain tumors; Magnetic resonance imaging;Diffusion-weighted magnetic resonance imaging; Magnetic resonance spectroscopy.

Clinico-pathological study in large posterior fossa midline tumors.

This cross sectional analytic study was carried out among the admitted patients of the department of Neurosurgery, Bangabandhu Sheikh Mujib Medical University, Dhaka during the period of 1st July 2002 to 31st December 2004. The age ranged from 2.5 years to 70 years. The size of all posterior fossa tumors at presentation were more than 3 cm and the mean size of posterior fossa tumor was 4.38 cm. 62% of posterior fossa mid-line tumors were mixed density in NECT (non-contrast CT).Regarding enhancement characteristics, mild-moderate enhancement and marked heterogeneous enhancement was equally distributed 46% followed by marked homogeneous enhancement only 08%.. The calcification was present only in 07 (14%) patients and most of them were ependymoma. Histopathologically, medulloblastoma was the common variety (32%). The CT scan diagnostic modality sensitivity, accuracy and positive predictive value were 100%, 84.78% and 84.78% respectively but in MRI diagnostic modality 100%, 91.30% and 91.30% respectively.

Medulloblastomas: new directions in risk stratification.

Medulloblastomas (MBs) are the most common malignant brain tumors in children. Current therapeutic approaches combine surgery, radiotherapy, and chemotherapy. Although, there has been significant improvement in long-term survival rates, the tumor remains incurable in about a third of patients while cognitive deficits and other sequelae of therapy are common among long-term survivors. Hence a major challenge remains to differentiate high-from low-risk patients and to tailor therapy based on the degree of biological aggressiveness. A clinical risk-stratification system has been widely used in MBs based on age, extent of resection and the Chang staging system. However, recent reports indicate that these clinical variables are inadequate methods of defining disease risk. This has prompted search for new markers for MB stratification. Recent studies indicate that the classification of MBs according to profiles of histopathology and molecular abnormalities possibly help better risk-stratification of patients, thereby rationalizing approaches to therapy, increasing cure rate, reducing long-term side effects and developing novel therapeutic strategies. The most accurate outcome prediction till date has been obtained through microarray gene expression profiling. In this article, the current histopathological classification and the recent advances in molecular genetics of MBs are reviewed. Global efforts to translate this knowledge of disease biology into clinical practice especially as outcome predictors are highlighted.

Patterns of malignant tumors of the brain and spinal cord in Bahrain: Fifty two year period

To review malignant neoplasms of the brain and spinal cord in Bahrain, and to compare the incidence with other parts of the world. A retrospective study. All Histopathology Departments in Bahrain. Data relating to all malignant CNS neoplasms which were diagnosed histologically in Bahrain were extracted from the relevant patient medical records. All tumors were histologically diagnosed in Bahrain between 1952 and 2004. There were 103 malignant CNS tumors representing 1.4% of all malignancies histologically reported during the same period. Of the 103 patients, 77 [74.8%] were Bahraini. Of the Bahraini patients, thirty-one [40.3%] were female and the male: female ratio was 1.48:1. Sixty-two of the 77 Bahraini tumors [80.5%] were primary brain tumors, nine [11.7%] were primary spinal cord tumors, and six [7.8%] were secondary tumors. Astrocytoma and medulloblastoma were the commonest primary malignant CNS neoplasms in both adults and children. The apparent incidence of malignant brain and spinal cord neoplasms in Bahrain is very low. The small Bahraini population, inefficient registration of cancers, and the lack of routine hospital autopsies are contributory factors for the low numbers observed

Meduloblastomas: achados clínicos, epidemiológicos e anátomo-patológicos de 28 casos / Medulloblastomas: clinical, epidemiological and pathological findings of 28 cases

Relatamos os achados clínicos, epidemiológicos e anátomo-patológicos de 28 casos de meduloblastomas. Dos 28 pacientes analisados, 22 eram do sexo masculino e seis do sexo feminino. As idades variaram de 1 a 50 anos, com média de 15 anos. Os sinais e sintomas de maior frequência foram cefaléia (64 por cento) e vômitos (64 por cento). Em relação ao tratamento, a maioria dos pacientes foi submetida a ressecção cirúrgica total (n=10) ou a exérese parcial (n=7). Com a exceção de um paciente que apresentava meduloblastoma desmoplásico, os demais apresentavam a forma clássica do meduloblastoma. Foi evidenciada uma taxa de recidiva tumoral total de 21 por cento (n=6) em 4 anos de seguimento clínico. A quimioterapia adjuvante parece contribuir para melhor evolução clínica dos pacientes. Estes achados aproximam-se dos encontrados na literatura, contribuindo para a compreensão do comportamento biológico deste tumor.

Analytical study of 253 cases of central nervous system tumours

This is an analytical study of 253 cases of central nervous system space occupying lesions which were received and diagnosed histologically at the histopathology department at the laboratory section in the specialized surgical hospital at Saddam's Medical City for the period between June 1990 till the end of December 1992. Out of these 253 cases, 231 cases of intracranial and intraspinal tumours were confirmed histologically and 22 cases were miscellaneous. 109 cases were reported among male patients and 122 cases among female. The highest peak incidence was reported in the fifth decade. Of these tumours Glioma constituded the highest incidence [39.4%], and the majority were of high grade malignancy and poor prognosis. This was found to be similar to other previous Iraqi studies and other similar studies reported in literatures

Meduloblastoma / Meduloblastoma

Se revisan todos los casos de Meduloblastoma diagnosticados y comprobados con Biopsia, en el Instituto de Anatomia Patologica del Hospital Universitario de San Vicente de Paul, desde el 1 de Enero de 1975, al 1 de Enero de 1980. Se encuentran 11 casos, todos suceptibles de seguimiento. Hay predominancia en hombres, en relacion de 1.75 a 1. El promedio de edad es de 8.6 anos, y el 64 X 100 de los pacientes son menores de 10 anos. La incidencia parece ir en aumento, a juzgar por el numero de pacientes que se han tabulado luego de la fecha del corte, y con miras a un informe posterior. La cefalea, el vomito y la ataxia, fueron los sintomas predominantes para la consulta. Una gran mayoria (mas del 90 X 100) de los tumores, son del vermis, y el resto del hemisferio, (tumor de adulto). Todos los pacientes fueron operados, la mayoria con reseccion macroscopicamente completa del tumor y 9 recibieron un regimen completo de terapia ionizante post-operatoria. De estos ultimos, la supervivencia es de 55.55 X 100 y la supervivencia global, es de 45.45 X 100. El tiempo entre cirugia y radioterapia fue en promedio 24 dias. La causa de muerte, es, casi siempre, la recidiva en fosa posterior