The Extended-Sphenoid Ridge Approach: A New Technique for the Surgical Treatment of Skull Base Tumors in Pediatric Patients.

The sphenoid ridge approach (SRA) was initially described as a surgical technique for treating vascular pathologies near the Sylvian fissure. However, limited studies have systematically explored the use of skull base techniques in pediatric patients. This study investigated an extended variation in the sphenoid ridge approach (E-SRA), which systematically removed the pterion, orbital walls (roof and lateral wall), greater sphenoid wing, and anterior clinoid process to access the base of the skull. OBJECTIVE: This report aimed to evaluate the advantages of the extradural removal of the orbital roof, pterion, sphenoid wing, and anterior clinoid process as a complement to the sphenoid ridge approach in pediatric patients. PATIENTS AND METHODS: We enrolled 36 patients with suspected neoplastic diseases in different regions. The E-SRA was performed to treat the patients. Patients were included based on the a priori objective of a biopsy or a total gross resection. The surgical time required to complete the approach, associated bleeding, and any complications were documented. RESULTS: Our results demonstrated that the proposed a priori surgical goal, biopsy, or resection were successfully achieved in all cases. In addition, using the E-SRA technique was associated with a shorter operative time, minimal bleeding, and a lower incidence of complications. The most frequently encountered complications were related to dural closure. CONCLUSIONS: The extended sphenoid ridge approach represents a safe and effective option for managing intracranial tumors in pediatrics.

Validation and Selection of New Reference Genes for RT-qPCR Analysis in Pediatric Glioma of Different Grades.

Gliomas are heterogeneous, solid, and intracranial tumors that originate from glial cells. Malignant cells from the tumor undergo metabolic alterations to obtain the energy required for proliferation and the invasion of the cerebral parenchyma. The alterations in the expression of the genes related to the metabolic pathways can be detected in biopsies of gliomas of different CNS WHO grades. In this study, we evaluated the expression of 16 candidate reference genes in the HMC3 microglia cell line. Then, statistical algorithms such as BestKeeper, the comparative ΔCT method, geNorm, NormFinder, and RefFinder were applied to obtain the genes most suitable to be considered as references for measuring the levels of expression in glioma samples. The results show that PKM and TPI1 are two novel genes suitable for genic expression studies on gliomas. Finally, we analyzed the expression of genes involved in metabolic pathways in clinical samples of brain gliomas of different CNS WHO grades. RT-qPCR analysis showed that in CNS WHO grade 3 and 4 gliomas, the expression levels of HK1, PFKM, GAPDH, G6PD, PGD1, IDH1, FASN, ACACA, and ELOVL2 were higher than those of CNS WHO grade 1 and 2 glioma biopsies. Hence, our results suggest that reference genes from metabolic pathways have different expression profiles depending on the stratification of gliomas and constitute a potential model for studying the development of this type of tumor and the search for molecular targets to treat gliomas.

Costotransversectomy plus hemilaminectomy as alternative surgical approach for extramedullary intradural thoracic schwannoma resection with and without extradural extension in pediatric population three cases and literature review.

Extramedullary intradural tumors constitute up to 25% of the spinal tumors. Commonly, schwannomas that presents with extradural and intradural compromise are called dumbbell-shaped tumor. The thoracic spine is a common localization for these tumors, especially in pediatric population. Given this surgically difficult localization, some classic approaches for spine tumors can be mixed with modified approaches like the costotransversectomy. The main objective of this report is expose three different pediatric cases in which mixed approach (costotransversectomy plus hemilaminectomy) was implemented for thoracic spine dumbbell-shaped schwannoma resection. It was achieved complete surgical resection without major perioperative complications in the three cases.

Effect of Nicotine on CYP2B1 Expression in a Glioma Animal Model and Analysis of CYP2B6 Expression in Pediatric Gliomas.

Cyclophosphamide (CPA) is a pro-drug commonly used in the chemotherapeutic schemes for glioma treatment but has high toxicity and the side effects include brain damage and even death. Since CPA is activated mainly by CY2B6, over-expression of the enzyme in the tumor cells has been proposed to enhance CPA activation. In this study, we explored the induction of the Cyp2b1 (homologous to CYP2B6) by nicotine in an animal rat model with glioma. Gene expression and protein levels were analyzed by RT-PCR and Western blot. Nicotine treatment increased CYP2B1 protein levels in the healthy animals' brain tissue. In the brain tissue of animals with glioma, the CYP2B1 showed a high expression, even before nicotine treatment. Nicotine did not increase significantly the CYP2B1 protein expression in the tumor, but increased its expression in the tumor vicinity, especially around blood vessels in the cortex. We also explored CY2B6 expression in glioma samples derived from pediatric patients. Tumor tissue showed a variable expression of the enzyme, which could depend on the tumor malignancy grade. Induction of the CYP2B6 in pediatric gliomas with lower expression of the enzyme, could be an alternative to improve the antitumoral effect of CPA treatment.

Estudio neuropsicológico pre y posquirúrgico en dos niños de 8 años de edad con tumor en fosa posterior / Neuropsychological study pre and post surgical in two children aged 8 years with posterior fossa tumor

Objetivo: Identificar y describir las diferencias neuropsicológicas antes y después de resecar el tumor en 2 pacientes de 8 años de edad con una neoplasia en la fosa posterior. Metodología: Se realizó evaluación neuropsicológica pre y posquirúrgica a 2 pacientes de 8 años de edad del Instituto Nacional de Pediatría, uno femenino con quiste aracnoideo en cisterna paravermiana y otro masculino con meduloblastoma en vermis y se compararon los datos obtenidos antes de extirpación de tumor y después de ella. Para la obtención del IQ se aplicó el WISC-IV y para las otras funciones, la Evaluación Neuropsicológica Infantil (ENI), para niños de 5 a 16 años, obteniéndose sus valores en percentiles que se igualaron con la clasificación cualitativa. Resultados: Los 2 pacientes presentaron deficiencias en el IQ, en Funciones Cognitivas, en las Habilidades de Rendimiento Académico, así como en sus Funciones Ejecutivas. A pesar de que no se aplicó quimioterapia ni radioterapia, tanto antes de la cirugía, como después de la extirpación del tumor, empeorando dichas funciones después de la extirpación. Conclusiones: Los tumores en Fosa Posterior originan diversas alteraciones neuropsicológicas similares a las observadas con lesiones en la corteza cerebral, dichas alteraciones se hacen más severas después de la extirpación del tumor; esta evolución puede presentar un dilema a la luz de la Bioética: ¿Se prolonga la vida a expensas de mayor deterioro neurocognitivo al quitar el tumor, o no se opera para evitar mayor deterioro en la calidad de vida y se reduce el tiempo de vida?.

Aim: Identify and describe the neuropsychological differences before and after surgery in 2 patients 8 years of age with a tumor in the posterior fossa. Methodology: Neuropsychological assessment was performed before and after surgery to 2 patients (8 years of age), one female with arachnoid cyst in paravermian cyst and another male with medulloblastoma in vermis and we compared the data obtained before removal of tumor and after. We use the following Neuropsychological Tests: WISC-IV was applied to assess IQ and Child Neuropsychological Assessment (ENI) was to evaluate cognitive functions. Results: The 2 patients had deficits in IQ, cognitive functions, the academic performance skills and his executive skills, even without chemotherapy or radiotherapy, both before surgery and after removal of the tumor. These functions worsened after surgery. Conclusions: Posterior fossa tumors originate many various neuropsychological similar to those observed in cerebral cortex, these changes are most evident after removal of the tumor, this evolution can present a dilemma in light of Bioethics: Is justified to prolong the life at expense of neurocognitive impairment, after removing a big tumor, or not to operate preventing further deterioration in the quality of life and reducing the lifetime?.

Stereotactic biopsy for brainstem tumors in pediatric patients.

OBJECTIVE: Our aim is to describe clinical and paraclinical features in patients who underwent stereotactic-guided biopsy for brainstem tumors. METHODS: A study of case series was made by reviewing the records of patients who underwent stereotactic biopsy for brainstem tumors. RESULTS: Stereotactic biopsy for brainstem tumors was performed (between 2000 and 2008) in 20 children (11 girls, and 9 boys), mean age 7.95 +/- 3.12 years at the time of diagnosis. The mean time from onset of symptoms to diagnosis was 6.59 +/- 13.58 months (0.50-60 months). The most frequent symptoms and signs at onset were related to disturbance of cerebellar function and cranial nerve nuclei. Location was pontomesencephalic (35%), pontine (30%), pontomedullar (25%), and in the whole brainstem (10%). The most common type of image was intrinsic-diffused (55%). The histopathology was anaplastic astrocytoma (30%), followed by fibrillary and pilocytic types (25% each), low-grade astrocytoma (5%), high-grade astrocytoma (5%), and normal tissue (10%). Mild complications were observed in only two cases. CONCLUSIONS: Stereotactic biopsy done for clarifiying a diagnostic imaging in brainstem tumors is important in obtaining a definitive diagnosis with a low rate of complications.

Chordoid meningioma of the foramen magnum in a child: a case report and review of the literature.

We report a 3-year-6-month-old boy with chordoid meningioma in the foramen magnum. Chordoid meningioma represents between 0.5 and 1.0% of all meningiomas, and it is frequently located in the supratentorial region. The patient started with an episode of instability, falls, and headache; after which, he developed cuadriparesis, cervical pain, and neck stiffness, which slightly improved after medical treatment, so he was referred to our hospital. Physical examination revealed left hemiparesis and cervical muscle spasm with left torticollis. Magnetic resonance imaging (MRI) demonstrated an intradural-extramedullary well-circumscribed, homogeneous enhancing mass, in the anterior part of the foramen magnum with cervical extension. The operative technique was the extreme-lateral craniocervical retrocondylar approach with total removal and dural coagulation. Histopathological examination demonstrated a chordoid meningioma, with meningotelial basophilic mucoid chordoma-like component in 80% of the tissue. The immunohistochemical stains were positive to epithelial membrane antigen, vimentin, and S-100 protein. At 10 months follow-up, the patient showed improvement in his neurological deficit with physical rehabilitation, and motor response in his extremities are now normal; neck stiffness with cervical spasm disappeared postoperatively. MRI showed no residual tumor. To our knowledge, this is the first report of a chordoid meningioma on the foramen magnum in a child.

Cerebral malignant nerve sheath tumor, triton tumor variant: case report.

A case of a cerebral malignant triton tumor in a 3-year-old boy with a 2-month history of frontal headache and no clinical evidence of neurofibromatosis is reported. The computed tomography (CT) scan showed a large, irregular tumor in the right parietooccipital lobe. A partial surgical resection was performed. Histologically, the tumor was highly cellular and consisted of spindle cells with hyperchromatic and pleomorphic nuclei. Focally, neoplastic cells with rhabdomyoblastic features were found. The immunohistochemical study showed that tumor cells were positive for S-100 protein and CD57, and the rhabdomyoblasts expressed desmin, Myo-D1, and myoglobin. During the postoperative period, a massive intraparenchymal hemorrhage was identified and surgical drainage was performed. The patient worsened and died 10 days after the first surgery. Postmortem study was not authorized. Six cases of cerebral malignant nerve sheath tumor have been described; however, primary intraparenchymal malignant triton tumor has not been previously described.

Survival of children under 3 years old with medulloblastoma: a study from the Mexican Cooperative Group for Childhood Malignancies (AMOHP).

BACKGROUND: The prognosis of medulloblastoma in children under 3 years of age is poor. METHODS: A retrospective analysis was performed to evaluate children under 3 years of age with medulloblastoma. Overall survival (OS) and progression-free survival (PFS) were assessed in children with and without metastasis. RESULTS: A total of 534 children were diagnosed with medulloblastoma during the study period, 49 (9.1%) of whom were under 3 years of age and were evaluated. Their ages ranged from 5 to 35 months with a mean of 18.5 months. In 39 (79.6%) of these patients the tumors were staged as T3M0 or under, while 10 (20.4%) had metastasis at diagnosis. The OS was 38% and PFS 37% in the whole series, while PFS was 32% in those with metastasis and 40% in those without ( P=0.78). For those who received radiotherapy the PFS was 62%, and in those not treated with radiotherapy PFS was nil ( P=0.0001). When the children were divided into those who received surgical treatment plus chemotherapy and those who received surgery plus radiotherapy plus chemotherapy, the PFS was nil and 66%, respectively ( P=0.00001). CONCLUSION: Because of the high morbidity of radiotherapy in children under 3 years old, surgery continues to be the basis of improved prognosis, followed by chemotherapy.

Neurocisticercosis en fase granulomatosa: presentación de un caso / A case report of glanulomatous-phase neurocysticercosis

El 13 de diciembre de 1997 acudió al servicio de urgencias del Hospital Mocel una paciente femenina de 27 años de edad con historia de cefalea de seis meses de evolución. Había sido diagnosticada en otro hospital con neurocisticercosis y tratada médicamente en forma muy irregular. Dos días antes de su ingreso presentó síndrome cráneo-hipertensivo con deterioro del estado de conciencia, hemiparesia derecha y síndrome de babinski bilateral de predominio derecho. Se le practicó una tomografía de cráneo urgente que demostró lesión anular con centro hipodenso, punto pericentral y bordes de hiperdensidad mayor, localizado en la porción anterior del lóbulo frontal izquierdo, hasta la convexidad, compresión del cuerno frontal, gran edema perilesional e importante efecto de masa, motivo por el cual fue sometida a una operación quirúrgica de urgencia

Tumores orbitarios en niños. Su abordaje quirúrgico transcraneal / Orbitary tumors in children. The transcranial surgical approach

De marzo de 1980 a diciembre de 1995 se trataron 23 pacientes con tumores orbitarios en el Departamento de Neurocirugía del Instituto Nacional de Pediatría (INP). En este trabajo se analiza edad, características clínicas, alteraciones radiológicas y de potenciales evocados; tipo de cirugía, diagnóstico histopatológico y resultados. En todos ellos se efectuó un abordaje craneoorbitario, tipo destechamiento simple, o bién, por fronto-orbitotomía. De estos pacientes, 11 tenían glioma del nervio óptico, tres displasia ósea fibrosa, dos meningioma, neurofibroma, histocitosis de células de Languerhans; uno astrocitoma anaplásico, teratoma, tumor neuroectodérmico primitivo y germinoma con áreas de coriocarcinoma. Se realizó, craneotomía con destechamiento orbitario (Nafziger) en 19 casos y fronto-orbitotomía en 4. Los resultados fueron clasificados de acuerdo a la escala de karnofsky; potenciales evocados postoperatorios, presencia de defecto estético y proptosis pulsátil. Buenos resultados fueron: Karnofsky mayor de 70, no recurrencia tumoral y no emperoramiento de potenciales Visuales; regulares: sin recurrencia tumoral y no empeoramiento de Potenciales Visuales; regulares: sin recurrencia tumoral, cambio en potenciales evocados, escala de Karnofsky entre 50 y 60; malos: recurrencia, lesión visual agregada en potenciales evocados y Karnofsky menor de 50. El reporte muestra la variedad de lesiones intraorbitarias que pueden ser abordadas por vía transcraneal