Pleomorphic Xanthoastrocytoma with Oligodendroglioma-Like Areas with Negative 1p19q Co-Deletion

The most common mixed glioma encountered in routine surgical practice is oligoastrocytoma (OA); however, its is currently considered a vanishing entity. The 2016 classification of the World Health Organization (WHO) discourages the diagnosis of tumors as mixed glioma. The recommendations are that diffuse gliomas, including those withmixed or ambiguous histological features, should be subjected tomolecular testing. Dual-genotype OAs are not yet a distinct entity or variant in the classification. We report a case ofmixed glioma: a pleomorphic xanthoastrocytoma (PXA)mixed with an oligodendroglioma. The immunohistochemistry (IHC) pattern of isocitrate dehydrogenase 1 (IDH1) negativity with retained nuclear expression of the alpha-thalassemia x-linked intellectual disability syndrome (ATRX) protein, and 1p19q co-deletion negativity in both the components enabled its identification as a mixed glioma rather than a collision tumor. To the best of our knowledge, the case herein presented is the fourth case of PXA with oligodendroglioma. Out of the other three reported cases, only one was of a collision tumor with a dual genotype, and the other two showed similar molecular signatures in both components. The present article discusses the histological, immunohistochemical and molecular features of the aforementioned case.

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.

A Diffuse Leptomeningeal Glioneural Tumor Case Producing Hydrocephalus and Polyradiculopathy

The present report describes the case of a male 17-year-old patient who progressively developed a hydrocephalus and polyradiculopathy due to involvement of central nervous system (CNS) by a diffuse leptomeningeal glioneuronal tumor (DLGNT). The tumor had partial remission in response to the treatment with radiotherapy plus procarbazine, lomustine, and vincristine (PCV) chemotherapy, and the patient had improvement in function and pain levels. The current knowledge about DLGNT, including its clinical manifestations, imaging findings, histological characteristics, and treatment are revised and discussed in the present paper.

Oligodendroglioma anaplásico quístico: reporte de caso / Anaplastic cystic oligodendroglioma: case report

Resumen: Los oligodendrogliomas anaplásicos son gliomas infiltrantes grado III de la organización mundial de la salud (OMS). Son tumores poco frecuentes y representan el 5-10% de todas las neoplasias intracraneales primarias. Su incidencia es de 0.3 por 100.000 habitantes por año en Estados Unidos. Con frecuencia se presentan en adultos entre los 40-60 años de edad. Los síntomas principales pueden ser déficit motor, déficit cognitivos y síntomas de aumento de la presión intracraneal. Su comportamiento en resonancia magnética muestra un aspecto heterogéneo con necrosis, degeneración quística y hemorragia intratumoral. Las presentaciones quísticas extensas son poco frecuentes. Reportamos el caso de un oligodendroglioma anaplásico de aspecto predominantemente quístico en una mujer joven.

Abstract: Anaplastic oligodendrogliomas are grade III infiltrating gliomas of the World Health Organization (WHO). They are rare tumors and represent 5-10% of all primary intracranial neoplasms. Its incidence is 0.3 per 100.000 inhabitants per year in the United States. They often occur in adults between 40-60 years of age. The main symptoms may be motor deficit, cognitive deficits and symptoms of increased intracranial pressure. Its behavior in MRI shows a heterogeneous appearance with necrosis, cystic degeneration and intratumoral hemorrhagic. Extensive cystic presentations are rare. We report the case of an anaplastic oligodendroglioma of predominantly cystic appearance in a young woman.

Oligodendroglioma with Sarcomatous Transformation: Case Report and Literature Review

Oligodendrogliomas are infiltrative tumors of the central nervous systemconsidered to be morphologically stable and to offer a better prognosis. Here, we describe the case of a 36- year-old man with an initial diagnosis of oligodendroglioma, World Health Organization (WHO) grade II, who presented transformation to a sarcomatous form, while maintaining the oligodendroglial component as well as the genetic characteristics of the initial tumor without having undergone any complementary treatments previously. Despite the favorable genetic characteristics, the tumor presented poor response to complementary treatments, and rapid progression, including spinal metastasis.

Superior Sagittal Sinus Invasion by Malignant Glioma: Case Report and Literature Review

Anaplastic oligodendrogliomas (AOs) correspond to 23% of all oligodendrogliomas. They correspond to a tumor with malignant histological characteristics, focal or diffuse, associated with a worse prognosis. In the present case report, we describe the case of a 30-year-old female submitted to resection of a right parietal lesion whose histology showed to be an AO. She underwent complementary treatment with chemotherapy and radiotherapy according to the Roger Stupp protocol. Four years after the initial diagnosis, there was tumor recurrence within the superior sagittal sinus, with no evidence of recurrence elsewhere. In the literature, we have found no similar published case reinforcing the rarity of this condition.

Posterior fossa oligodendroglioma.

Oligodendroglioma are the tumors of glial cells. They are rare in children and are more common in the cerebral hemispheres. A rare case of infratentorial oligodendroglioma in a female child is being reported here.