Application of Machine Learning for Classification of Brain Tumors: A Systematic Review and Meta-Analysis.

BACKGROUND: Classifying brain tumors accurately is crucial for treatment and prognosis. Machine learning (ML) shows great promise in improving tumor classification accuracy. This study evaluates ML algorithms for differentiating various brain tumor types. METHODS: A systematic review and meta-analysis were conducted, searching PubMed, Embase, and Web of Science up to March 14, 2023. Studies that only investigated image segmentation accuracy or brain tumor detection instead of classification were excluded. We extracted binary diagnostic accuracy data, constructing contingency tables to derive sensitivity and specificity. RESULTS: Fifty-one studies were included. The pooled area under the curve for glioblastoma versus lymphoma and low-grade versus high-grade gliomas were 0.99 (95% confidence interval [CI]: 0.98-1.00) and 0.89, respectively. The pooled sensitivity and specificity for benign versus malignant tumors were 0.90 (95% CI: 0.85-0.93) and 0.93 (95% CI: 0.90-0.95), respectively. The pooled sensitivity and specificity for low-grade versus high-grade gliomas were 0.99 (95% CI: 0.97-1.00) and 0.94, (95% CI: 0.79-0.99), respectively. Primary versus metastatic tumor identification yields sensitivity and specificity of 0.89, (95% CI: 0.83-0.93) and 0.87 (95% CI: 0.82-0.91), correspondingly. The differentiation of gliomas from pituitary tumors yielded the highest results among primary brain tumor classifications: sensitivity of 0.99 (95% CI: 0.99-1.00) and specificity of 0.99 (95% CI: 0.98-1.00). CONCLUSIONS: ML demonstrated excellent performance in classifying brain tumor images, with near-maximum area under the curves, sensitivity, and specificity.

Biomarcadores radiológicos en RM para una aproximación al diagnóstico molecular en gliomas IDH-mutados (grado II y III) / MR Imaging Biomarkers for a Diagnostic Approach of IDH-mutated Gliomas (Grades II/III)

Resumen Objetivo: Analizar características por resonancia magnética (RM) de gliomas IDH-mutados (grado II y III) en base a parámetros cualitativos, a fin de valorar el rendimiento del signo del mismatch T2-FLAIR y otras características morfológicas de los tumores, en predecir el estado del 1p/19q y su reproducibilidad interobservador. Métodos Estudio retrospectivo, descriptivo y analítico sobre una cohorte de 53 gliomas IDH-mutados (grado II y III) y molecularmente definidos respecto al 1p/19q, seleccionados a partir de la base de datos de la institución, durante el periodo 2014- 2019. Dos neuroradiólogos evaluaron características imagenológicas de forma independiente y enmascarada al diagnóstico: mismatch T2-FLAIR, localización tumoral, bordes, señal, infiltración cortical e inhomogeneidad en T2. Los casos discordantes fueron evaluados por un tercer neuroradiólogo de mayor experiencia. Resultados: Treinta de 53 (56,6%) gliomas fueron no codelecionados, y 23/53 (43,4%) codelecionados. El signo del mismatch T2-FLAIR fue positivo en 16/53 (30,18%) pacientes, 15/16 (93,75%) no codelecionados y 1/16 (6,25%) codelecionado (Exacto de Fisher p = <,0001). Los dos evaluadores demostraron una concordancia interobservador casi perfecta para ese signo, κ =,907 (95% CI, 0,781 a 1,0). La especificidad y el valor predictivo positivo del signo para predecir la ausencia de la codeleción fue de un 95,7% y un 93,8% respectivamente. Discusión: La reciente actualización en la clasificación de los gliomas los clasifica acorde a su perfil molecular. En los últimos años, varios investigadores han estudiado características morfológicas por RM de los tumores con la intención de predecir las características moleculares de los mismos. Conclusión: En nuestra población, el signo del mismatch T2-FLAIR es el único biomarcador radiológico que muestra asociación estadísticamente significativa en predecir la ausencia de codeleción en los gliomas IDH-mutados (grado II y III), con una alta especificidad y un alto valor predictivo positivo.

Abstract Objective: To analyze magnetic resonance (MR) characteristics of IDH-mutated gliomas (grades II/III) utilizing qualitative parameters with the goal of assessing the performance of the T2-FLAIR mismatch sign and other morphological characteristics of tumors in predicting the 1p/19q co-deletion status as well as inter-observer reproducibility. Methods: Retrospective and descriptive study analyzing a cohort of 53 IDH-mutated lower-grade (grades II/III) gliomas with known 1p/19q co-deletion status. Patients meeting selection criteria for this study were taken from our institutional data from 2014-2019. Two neuroradiologists assessed the following imaging characteristics independently, and blinded from the diagnosis: T2-FLAIR mismatch, tumor location, borders, signal characteristics, cortical infiltration and T2* inhomogeneity. In the event of discordant interpretations, a third senior neuroradiologist also evaluated the case. Results: 23 of the 53 (43.4%) gliomas demonstrated 1p/19q co-deletion and 30 of 53 (56.6%) did not. T2-FLAIR mismatch was positive in 16 of 53 cases (30.2%) with 15 of 16 (93.8%) demonstrating no co-deletion and 1/16 (6.25%) with co-deletion (Fisher's exact p = < .0001). The two readers showed an almost perfect interreader agreement for this sign κ = 0.907 (95% CI, 0.781 to 1.0). Specificity and positive predictive value of the sign to predict the absence of co-deletion was 95.7% and 93.8% respectively. Discussion: The recent update in classification of lower-grade gliomas segregates gliomas according to molecular profile. In the recent past, many researchers have studied MR morphologic characteristics of these tumors with the intention of predicting molecular features of said tumors Conclusion: In our patient population, T2-FLAIR mismatch sign is the only radiologic biomarker that shows statistically significant association with the absence of 1p/19q co-deletion in lower-grade gliomas, with high specificity and positive predictive value.

Perfil Anatomopatológico e Imuno-histoquímico de Gliomas de Pacientes da Região de Maringá-PR / Anatomopathological and Immunohistochemical Profile of Gliomas of Patients in the Region of Maringá-PR / Perfil Anatomopatológico e Inmunohistoquímico de Gliomas en Pacientes la Región de Maringá-PR

Introdução: Os gliomas representam 80% dos tumores do sistema nervoso central. A Organização Mundial da Saúde (OMS) adicionou, em 2016, critérios moleculares na classificação dos gliomas. A fisiopatologia e os fatores de risco desses tumores ainda não são totalmente conhecidos. Objetivo: Realizar uma análise retrospectiva dos laudos anatomopatológicos e imuno-histoquímicos de gliomas. Método: Estudo transversal, retrospectivo e descritivo, a partir de exames anatomopatológicos e imuno-histoquímicos realizados entre janeiro de 2014 e dezembro de 2018 em um laboratório de anatomia patológica na cidade de Maringá-PR. Dos 234 laudos relacionados com o termo glioma, 204 foram selecionados para este estudo. Resultados: Foram encontrados tumores astrocitários, ependimários e oligodendrogliais, sendo que os astrocitomas corresponderam à maioria (86,8% dos casos encontrados). A média de idade ao diagnóstico foi de 51,8 anos e houve maior prevalência desses tumores no sexo masculino. Também foram analisadas mutações detectáveis por imuno-histoquímica como p53 (mutada em 66,7% dos testados), isocitrato desidrogenase (IDH) (28,6% mutados), X-linked alpha-thalassemia mental retardation (ATRX) (21,0%) e marcadores diagnósticos como o epithelial membrane antigen (EMA) positivo em todos os ependimomas analisados. Conclusão: É inegável a necessidade de novas pesquisas sobre os gliomas tanto no campo epidemiológico, tendo em vista a nova classificação, quanto no escopo fisiopatológico e clínico, com o objetivo de melhorar o entendimento sobre a patologia e o tratamento dos pacientes

Introduction: Gliomas represent 80% of the central nervous system tumors. World Health Organization (WHO) has added, in 2016, molecular features to the classification of gliomas. The pathophysiology and risk factors of these tumors are not yet fully understood. Objective: Perform a retrospective analysis of immunohistochemical and anatomopathological reports of gliomas. Method: Cross-sectional, retrospective and descriptive study carried out from anatomopathological and immunohistochemical exams made between January 2014 and December 2018 in a pathological anatomy laboratory in the city of Maringá-PR. Of the 234 reports related to the term glioma, 204 were selected for this study. Results: Astrocytic, ependymal and oligodendroglial tumors were found, with astrocytomas accounting for the majority (86.8% of the cases found). Mean age at diagnosis was 51.8 years and the prevalence was higher in men. Furthermore, immunohistochemically detectable mutations were analyzed, such as p53 (mutated in 66.7% of those tested), isocitrate dehydrogenase (IDH) (28.6% mutated), X-linked alpha-thalassemia mental retardation (ATRX) (21.0%) and diagnostic markers such as positive epithelial membrane antigen (EMA) in all analyzed ependymomas. Conclusion: The necessity of further researches on gliomas is undeniable , both epidemiologically considering the new classification and within the clinical and pathophysiological scope in order to improve the understanding of the pathology and the treatment for the patients

Introducción: Los gliomas representan 80% de los tumores del sistema nervioso central. La Organización Mundial de la Salud (OMS) agregó, en 2016, criterios moleculares sobre como clasificar los gliomas. La fisiopatología y los factores de riesgo de estos tumores aún no se comprenden completamente. Objetivo: Realizar un análisis retrospectivo de informes inmunohistoquímicos y anatomopatológicos de gliomas. Método: Estudio transversal, retrospectivo y descriptivo con base em pruebas anatomopatológicas e inmunohistoquímicas realizadas entre enero de 2014 y diciembre de 2018 en un laboratorio de anatomía patológica de la ciudad de Maringá-PR. De los 234 informes relacionados con el término glioma, se seleccionaron 204 para este estudio. Resultados: Se encontraron tumores astrocíticos, ependimarios y oligodendrogliales, siendo los astrocitomas la mayoría (86,8% de los casos encontrados). La edad media al diagnóstico fue de 51,8 años y hubo una mayor prevalencia de estos tumores en el sexo masculino. También se analizaron mutaciones detectables inmunohistoquímicamente, como p53 (mutado en 66,7% de los analizados), isocitrato desidrogenase(IDH) (28,6% mutado), X-linked alpha-thalassemia mental retardation (ATRX) (21,0%) y marcadores de diagnóstico como epithelial membrane antigen (EMA) positivo en todos los ependimomas analizados. Conclusión: Es innegable la necesidad de profundizaren las investigaciones sobre los gliomas, tanto en el campo epidemiológico, ante la nueva clasificación, como en el ámbito fisiopatológico y clínico, con el objetivo de mejorar el conocimiento sobre la patología y el tratamiento de los pacientes

Evaluación semicuantitativa de gliomas cerebrales en adultos: un enfoque de las características neuropatológicas.

INTRODUCTION: Gliomas are neoplasms with high recurrence and mortality. Due to the difficulty to apply the World Health Organization (2016) classification, developing countries continue to use histological evaluation to diagnose and classify these neoplasms. OBJECTIVE: To develop a semi-quantitative scale to numerically grade gliomas morphological characteristics. METHOD: A cohort of patients with gliomas was assessed and followed for 36 months. Tumor tissue sections were analyzed and graded, including aspects such as cell line, cellularity, nuclear pleomorphism, mitosis, endothelial hyperplasia, hypoxic changes, apoptotic bodies, necrosis, hemorrhage and proliferation index. RESULTS: 58 cases were analyzed. Low-grade gliomas median score was 12 points (9 and 13.5 for percentiles 25 and 75, respectively), whereas for high-grade gliomas it was 17 points (16 and 20.5 for percentiles 25 and 75, respectively) (p < 0.0001). Thirty-six-month survival of patients with low (13/17) and high grade gliomas (6/41) was also significantly different (p < 0.0001). CONCLUSIONS: The semi-quantitative morphological scale allows an objective evaluation of gliomas, with an adequate correlation between the score, tumor grade and survival time.

INTRODUCCIÓN: Los gliomas son neoplasias con alta recurrencia y mortalidad. Por la dificultad para aplicar la clasificación de la Organización Mundial de la Salud (2016), los países en desarrollo siguen utilizando la evaluación histológica para diagnosticarlos y clasificarlos. OBJETIVO: Desarrollar una escala semicuantitativa para calificar numéricamente las características morfológicas de los gliomas. MÉTODO: Cohorte de pacientes con gliomas evaluada y seguida durante 36 meses. Se analizaron y calificaron cortes del tejido tumoral, incluyendo aspectos como estirpe celular, celularidad, pleomorfismo nuclear, mitosis, hiperplasia endotelial, cambios hipóxicos, cuerpos apoptóticos, necrosis, hemorragia e índice de proliferación. RESULTADOS: Se analizaron 58 casos. La mediana de la calificación de los gliomas de bajo grado fue de 12 puntos (percentiles 25 y 75 de 9 y 13.5, respectivamente) y la de los gliomas de alto grado fue de 17 puntos (percentiles 25 y 75 de 16 y 20.5, ­respectivamente) (p < 0.0001). La supervivencia a 36 meses de los pacientes con gliomas de bajo (13/17) y alto grado (6/41) también fue significativamente diferente (p < 0.0001). CONCLUSIONES: La escala morfológica semicuantitativa permite una evaluación objetiva de los gliomas, con una adecuada correlación entre la calificación, el grado del tumor y el tiempo de supervivencia.

Semi-quantitative evaluation of brain gliomas in adults: A focus on neuropathological characteristics

Introduction: Gliomas are neoplasms with high recurrence and mortality. Due to the difficulty to apply the World Health Organization (2016) classification, developing countries continue to use histological evaluation to diagnose and classify these neoplasms. Objective: To develop a semi-quantitative scale to numerically grade gliomas by its morphological characteristics. Method: A cohort of patients with gliomas was assessed and followed for 36 months. Tumor tissue sections were analyzed and graded, including aspects such as cell line, cellularity, nuclear pleomorphism, mitosis, endothelial hyperplasia, hypoxic changes, apoptotic bodies, necrosis, hemorrhage and proliferation index. Results: 58 cases were analyzed. Low-grade gliomas median score was 12 points (9 and 13.5 for percentiles 25 and 75, respectively), whereas for high-grade gliomas it was 17 points (16 and 20.5 for percentiles 25 and 75, respectively) (p < 0.0001). Thirty-six-month survival of patients with low (13/17) and high grade gliomas (6/41) was also significantly different (p < 0.0001). Conclusions: The semi-quantitative morphological scale allows an objective evaluation of gliomas, with an adequate correlation between the score, tumor grade and survival time.

Semi-quantitative evaluation of brain gliomas in adults: A focus on neuropathological characteristics.

INTRODUCTION: Gliomas are neoplasms with high recurrence and mortality. Due to the difficulty to apply the World Health Organization (2016) classification, developing countries continue to use histological evaluation to diagnose and classify these neoplasms. OBJECTIVE: To develop a semi-quantitative scale to numerically grade gliomas by its morphological characteristics. METHOD: A cohort of patients with gliomas was assessed and followed for 36 months. Tumor tissue sections were analyzed and graded, including aspects such as cell line, cellularity, nuclear pleomorphism, mitosis, endothelial hyperplasia, hypoxic changes, apoptotic bodies, necrosis, hemorrhage and proliferation index. RESULTS: 58 cases were analyzed. Low-grade gliomas median score was 12 points (9 and 13.5 for percentiles 25 and 75, respectively), whereas for high-grade gliomas it was 17 points (16 and 20.5 for percentiles 25 and 75, respectively) (p < 0.0001). Thirty-six-month survival of patients with low (13/17) and high grade gliomas (6/41) was also significantly different (p < 0.0001). CONCLUSIONS: The semi-quantitative morphological scale allows an objective evaluation of gliomas, with an adequate correlation between the score, tumor grade and survival time.

Diffuse low-grade glioma: a review on the new molecular classification, natural history and current management strategies.

The management of diffuse supratentorial WHO grade II glioma remains a challenge because of the infiltrative nature of the tumor, which precludes curative therapy after total or even supratotal resection. When possible, functional-guided resection is the preferred initial treatment. Total and subtotal resections correlate with increased overall survival. High-risk patients (age >40, partial resection), especially IDH-mutated and 1p19q-codeleted oligodendroglial lesions, benefit from surgery plus adjuvant chemoradiation. Under the new 2016 WHO brain tumor classification, which now incorporates molecular parameters, all diffusely infiltrating gliomas are grouped together since they share specific genetic mutations and prognostic factors. Although low-grade gliomas cannot be regarded as benign tumors, large observational studies have shown that median survival can actually be doubled if an early, aggressive, multi-stage and personalized therapy is applied, as compared to prior wait-and-see policy series. Patients need an honest long-term therapeutic strategy that should ideally anticipate neurological, cognitive and histopathologic worsening.

Gliomas de alto grado en adultos / High grade gliomas in adults

Malignant gliomas represent 80 percent of primary malignant central nervous system tumors. It generally presents with headache, epilepsy, cognitive change, dysphasia, or progressive hemiparesia. Current standard treatment for malignant glioma includes: surgical resection or biopsy, radiation therapy and/or chemotherapy. The prognosis of malignant gliomas is still dismal despite aggressive treatment attempts. Understanding the molecular pathogenesis of glioma may lead to a rational development of new therapies. This review summarizes the diagnosis and management of these tumors in adults.

Estado actual de la terapia antiangiogénica en el manejo de gliomas de alto grado / Present state of the antiangiogenic therapy in the management of gliomas of high degree

High grade gliomas are lethal cancers. Despite recent advances in surgery, radiotherapy and chemotherapy, the overall survival is 15 months for glioblastoma. They are among the most vascular of human tumors, making them especially attractive targets for angiogenesis inhibitors. Most clinical trials of these agents as monotherapy have failed to demonstrate survival benefit in unselected high grade glioma patient populations. Several mechanisms of treatment failure have been postulated. In response, there are new intervention strategies on course: the combination of target therapy with classic chemotherapy, multitargeted kinase inhibitors and combinations of single-targeted kinase inhibitors and the identification of correlative biomarkers. These advances provide real opportunities for the development of effective therapies for high grade gliomas.

Patterns of neuroaxis dissemination of gliomas: suggestion of a classification based on magnetic resonance imaging findings.

BACKGROUND: Local invasion is the hallmark of malignant glioma dissemination. Leptomeningeal dissemination, a serious complication of malignant gliomas, has been increasingly observed. To correlate the physiopathologic mechanisms and the magnetic resonance imaging patterns of neuroaxis dissemination, a classification of malignant glioma dissemination is proposed (Instituto de Neurologia de Curitiba Classification). METHODS: This classification includes the following patterns of dissemination: leptomeningeal (type I), nodular (type Ia), diffuse (type Ib); subependymal (type II); satellite (type IIIa, IIIb); and mixed (type IV), combination of 2 or more previous types. Of 138 patients with histologically confirmed gliomas treated between 2000 and 2004, 10 presented neuroaxis dissemination and were evaluated. RESULTS: The distribution of dissemination patterns was as follows: subependymal, 4 of 10; diffuse leptomeningeal, 1 of 10; nodular leptomeningeal, 1 of 10; and satellite, 4 of 10. Mean interval between primary tumor and dissemination was 4 months. The most frequent glioma dissemination risk factor was entering the ventricular system during surgery. CONCLUSIONS: Improvements in our diagnostic imaging capabilities have contributed to a better understanding of the patterns of malignant glioma dissemination. Using this information, we present a useful classification scheme, applicable to patients with neuroaxis dissemination, which will help standardize future discussions aimed at understanding these patterns of tumor spread.

[Multiple gliomas. Illustrative cases of 4 different presentations]. / Gliomas múltiplos: casos ilustrativos de quatro formas de apresentação.

Multiple gliomas are uncommon and may be classified according to: a) the time of presentation in early (at diagnosis) or late (during treatment); b) the characteristics of computed tomography or magnetic resonance imaging (CT/MRI) in multifocal (with evidence of spread) and multicentric (without evidence of spread). From 212 patients with histopathologic diagnosis of glioma evaluated from March/90 to September/99, 15 (7%) had multiple lesions. We describe 4 patients: early multicentric, late multicentric, early multifocal and late multifocal, with emphasis on characteristics of CT/MRI and possible differential diagnosis. The differential diagnosis of multiple lesions in the central nervous system includes mainly infectious/inflammatory diseases and metastasis, however multiple gliomas should always be considered, even in patients with known systemic cancer, as described by others. Considering that CT/MRI features are not definite, the diagnosis should always be confirmed by histopathologic examination.

Gliomas múltiplos: casos ilustrativos de quatro formas de apresentação / Multiple gliomas: illustrative cases of 4 different presentations

Os gliomas múltiplos são relativamente raros e podem ser classificados didaticamente de acordo com: a) a época da apresentação, em precoces (quando presentes desde o diagnóstico inicial) ou tardios (quando presentes durante a evolução); e b) as características dos exames de imagem, em multifocais (quando há evidência de contiguidade das lesões) ou multicêntricos (quando não é possível identificar contiguidade das lesões). Entre os 212 pacientes com diagnóstico anatomopatológico de glioma, acompanhados prospectivamente no setor de neuro-oncologia de março/90 a setembro/99, 15 (7 por cento) apresentaram lesões múltiplas. Descrevemos 4 casos característicos de cada uma das possíveis apresentações: multicêntrico precoce, multicêntrico tardio, multifocal precoce e multifocal tardio, com ênfase nas características de imagem e possíveis diagnósticos diferenciais. O diagnóstico diferencial das lesões múltiplas no sistema nervoso central inclui doenças inflamatórias e infecciosas, além de metástases. A possibilidade de tratar-se de tumores de origem glial, entretanto, deve ser sempre lembrada, mesmo naqueles pacientes com diagnóstico de neoplasia sistêmica conhecida, conforme já descrito na literatura. O diagnóstico histológico se impõe, uma vez que as características de imagem não permitem diagnóstico de certeza.

[Comparative structural study of the glial blastomas of the central nervous system]. / Estudio estructural comparativo de los blastomas gliales del sistema nervioso central.

The objective of our work is to compare 2 diagnostics methods and demonstrate the similarities of the different Central Nervous System Glial Tumor Classifications. Immuno-marking techniques for gliofibrilar acid protein (GFAP), and special silver impregnations to compare the results according to the last histogenetic interpretations were used. 95 Gliomas were studied with hematoxiline-eosine and silver techniques, and in 58 randomized selected cases the technique for GFAP was also used. Both methods showed the same results in the diagnosis of Glial Tumors whose cells possess gliofibrils: Glioepitelioma (Ependymoma), Glioblastoma, Astroblastoma, and Astrocytoma. In the Oligodendrioglomas whose cells possess microtubules but not gliofibrils, the silver techniques marked these cells and their prolongations while the technique for GFAP did not. Regarding Gliomas, there are similarities by comparing the Del Río Ortega-Polak classification with those of the WHO and other authors. There are differences only in the "names" of some tumors or in their histogenetic interpretation, which are not substantial and are confined to the "Polar Espongioblastoma" and "Gliosarcoma". Therefore, we think that the recognition of the Del Río Hortega-Polak classification is justified.

Estudio estructural comparativo de los blastomas gliales del sistema nervioso central / Comparative structural study of the glial blastomas of the central nervous system

El OBJETIVO de nuestro trabajo es comparar 2 métodos diagnósticos, y demostrar las semejanzas de las distintas Clasificaciones de los Tumores Gliales del Sistema Nervioso Central. Se realizaron técnicas de inmunomarcación para proteína gliofibrilar ácida (GFAP), e impregnaciones argénticas especiales para confrontar los hallazgos según las últimas interpretaciones histogenéticas. Estudiamos 95 Gliomas con hematoxilina-eosina y técnicas argénticas, y en 58 casos tomados al azar realizamos además la técnica para GFAP. Con ambos métodos obtuvimos resultados iguales en el diagnóstico de tumores gliales cuyas células poseen gliofibrillas: Glioepiteliomas (Ependimonas), Glioblastomas, Astroblastomas y Astrocitomas. En los Oligodendrogliomas cuyas células no poseen gliofibrillas pero sí microtúbulos, las técnicas argénticas marcaron estas células y sus prolongaciones, no así la técnica para GFAP. Hay semejanzas al comparar la Clasificación de Del Río Horttega-Polak con la de la OMS y la de otros autores, en lo referente a los Gliomas. Sólo hay diferencias en la nomenclatura de algunos tumores o en su interpretación histogenética, que no son sustanciales y están limitados, que no son sustanciles y están limitados al "Espongioblastoma Polar" y al "Gliosarcoma". Por lo tanto, creemos que la revalorización de la Clasificación de Del Río Hortega-Polak está justificada.

Estudio estructural comparativo de los blastomas gliales del sistema nervioso central / Comparative structural study of the glial blastomas of the central nervous system

El OBJETIVO de nuestro trabajo es comparar 2 métodos diagnósticos, y demostrar las semejanzas de las distintas Clasificaciones de los Tumores Gliales del Sistema Nervioso Central. Se realizaron técnicas de inmunomarcación para proteína gliofibrilar ácida (GFAP), e impregnaciones argénticas especiales para confrontar los hallazgos según las últimas interpretaciones histogenéticas. Estudiamos 95 Gliomas con hematoxilina-eosina y técnicas argénticas, y en 58 casos tomados al azar realizamos además la técnica para GFAP. Con ambos métodos obtuvimos resultados iguales en el diagnóstico de tumores gliales cuyas células poseen gliofibrillas: Glioepiteliomas (Ependimonas), Glioblastomas, Astroblastomas y Astrocitomas. En los Oligodendrogliomas cuyas células no poseen gliofibrillas pero sí microtúbulos, las técnicas argénticas marcaron estas células y sus prolongaciones, no así la técnica para GFAP. Hay semejanzas al comparar la Clasificación de Del Río Horttega-Polak con la de la OMS y la de otros autores, en lo referente a los Gliomas. Sólo hay diferencias en la nomenclatura de algunos tumores o en su interpretación histogenética, que no son sustanciales y están limitados, que no son sustanciles y están limitados al "Espongioblastoma Polar" y al "Gliosarcoma". Por lo tanto, creemos que la revalorización de la Clasificación de Del Río Hortega-Polak está justificada. (AU)

Tumores sellares y suprasellares que afectan al quiasma y nervios ópticos. III. Gliomas diencefálicos de nervios y quiasma ópticos, ependimomas y subependimomas, espongioneuroblastomas, hemangionas diencefálicos, alteraciones inflamatorias / Sellar and suprasellar tumors afecting chiasma and optic nerves. Part III. Diencephalic gliomas of the chiasma and optic nerve, ependimomas ans subepondimomas, spongioneuroblastomas, diencephalic hemangiomas and inflamatory alterations

Las vías visuales anteriores pueden dañarse por: Tumores que se originen del quiasma y nervio óptico (astrocitoma y glioblastoma multiforme), adenomas pituitarios y arqueoblastomas, gliomas diencefálicos, espongioneuroblastoma, ependimomas y excepcionalmente por parásitos o procesos inflamatorios, granulomatosos que actúan como una masa ocupativa intracraneana. Es necesario tener en mente estos padecimientos en el diagnóstico diferencial. Es frecuentemente que los pacientes acudan primero con el optometrista o el oftalmólogo, en este último es en quien recae la responsabilidad más importante en la prontitud del diagnóstico