1/37. Cerebellar papillary meningioma in a 3-year-old boy: the usefulness of electron microscopy for diagnosis.We report one case of papillary meningioma located in the posterior fossa in a 3-year-old boy. Despite a gross total resection, a major recurrence occurred 6 months later that was operated on. Eight months later, another recurrence was observed with intracranial metastases and dissemination throughout the cerebrospinal fluid. The tumor had a papillary architecture more obvious in the recurrence. Areas of necrosis were numerous. Tumor cells had large clear atypical nuclei. Many mitotic figures were seen and Ki-67 labeling index was high. The tumor cells were immunoreactive for vimentin and polysialylated neural cell adhesion molecule only, ruling out a diagnosis of ependymoma or medulloblastoma. diagnosis of meningioma was done by electron microscopy, which showed interdigitating cytoplasmic processes and cell junctions. Cytogenetic study revealed unusual karyotypic abnormalities.- - - - - - - - - - ranking = 1keywords = ependymoma (Clic here for more details about this article) |
2/37. Signet-ring cell ependymoma: case report with implications for pathogenesis and differential diagnosis.We describe light microscopic, immunohistochemical and ultrastructural features of a signet-ring cell ependymoma (WHO grade II) identified in a surgically resected left cerebellar cystic tumor from a 64-year-old man. Part of the tumor showed clear-cell differentiation. Immunohistochemical coexpression of glial fibrillary acidic protein and epithelial membrane antigen, characteristic of ependymoma, was detected in both components. Sinuous intermediate junctions, cytoplasmic lumina, and scant astroglial filaments were demonstrated by electron microscopy. Signet-ring cell change was shown to be induced by disproportionate cavitation of either microvillus-bearing cytoplasmic lumina or microrosettes. The staining qualities of clear cells were mainly due to paucity and degeneration of subcellular organelles. Therefore, signet-ring cell ependymomas represent a unique anomaly of intra- and extracellular compartmentalization to be distinguished from various unrelated forms of cytoplasmic volume increase, resulting in an optically similar "empty" appearance of tumor cells. As a clinically relevant consequence, signet-ring cell ependymoma must be included in the differential diagnosis of primary or metastatic neoplasms of the central nervous system, having in common a phenotype characterized by overdeveloped optically lucent cell bodies.- - - - - - - - - - ranking = 8keywords = ependymoma (Clic here for more details about this article) |
3/37. Bone metastases from a cerebral and sacral ependymoma. Report of a case.A case of cerebral and sacral ependymoma revealed by cerebellar syndrome and sciatica in a 68-year-old man is reported. Bone metastases were diagnosed seven months after surgical excision of the brain tumor.- - - - - - - - - - ranking = 5keywords = ependymoma (Clic here for more details about this article) |
4/37. Visual agnosia after treatment of a posterior fossa ependymoma in a 16-month-old girl.We present the clinical observation of a 16-month-old girl treated for a posterior fossa ependymoma who experienced severe and delayed visual dysfunction. She was initially treated by surgery and conventional chemotherapy. When she relapsed at age 3 years, the salvage treatment combined high-dose chemotherapy, second surgery, and local irradiation. At age 4 years, disturbed gait and dysarthric speech appeared rapidly, and she became unable to recognize objects and people. Computed tomography revealed bilateral calcifications in the cerebellum and temporal and occipital lobes but no relapse. The neuropsychologic evaluations revealed signs of visual agnosia and marked intellectual impairment. The role of the different treatment modalities in the pathogenesis of this unusual syndrome is discussed.- - - - - - - - - - ranking = 5keywords = ependymoma (Clic here for more details about this article) |
5/37. neuroimaging of cerebellar liponeurocytoma. Case report.Cerebellar liponeurocytoma is a newly recognized, rare clinicopathological entity. It manifests with posterior fossa symptoms in adults and is characterized histopathologically by advanced neuronal and focal lipomatous differentiation with a low level of mitotic activity. The authors analyzed the computerized tomography (CT) and magnetic resonance (MR) imaging findings in two patients with histopathologically proven cerebellar liponeurocytomas and review the literature. Cerebellar liponeurocytoma may be suspected on the basis of neuroimaging findings that demonstrate an intraaxial neoplasm with the propensity for exophytic growth into the adjacent subarachnoid spaces. On CT scans, the tumor commonly presents as a hypointense mass with intermingled areas exhibiting the attenuation values of fatty tissue. On T1-weighted MR images, the tumor is hypointense with scattered foci of hyperintense signal and displays moderate contrast enhancement. On T1-weighted MR images, the tumor is slightly hyperintense to cortex, and edema is usually absent. Areas of fat density as assessed on CT scans and of T1 hyperintensity seen on MR images help to distinguish this rare neoplasm from the more common adult medulloblastomas or ependymomas. The available follow-up data indicate a favorable clinical prognosis; therefore, knowledge and precise characterization of this tumor is important to avoid unnecessary adjuvant radio- or chemotherapy.- - - - - - - - - - ranking = 1keywords = ependymoma (Clic here for more details about this article) |
6/37. Cerebellar central liponeurocytoma.Cerebellar liponeurocytoma is a rare, benign neuroepithelial tumor that occurs exclusively in the cerebellum of adults. Its salient histological features include advanced neuronal/neurocytic differentiation, focal vacuolated cells resembling mature adipose cells, low mitotic activity, and lack of endothelial proliferation and/or necrosis. The morphological appearance of this neoplasm can be confused with that of oligodendroglioma, neurocytoma, ependymoma, medulloblastoma, hemangioblastoma, metastatic renal cell carcinoma, and other clear cell carcinomas. Its full biological potential and histological features, however, have not been fully exploited due to the rarity of this tumor. The authors describe a case with clinical, imaging, histological, immunohistochemical, and ultrastructural features.- - - - - - - - - - ranking = 1keywords = ependymoma (Clic here for more details about this article) |
7/37. Pigmented ependymoma with lipofuscin and neuromelanin production.We report an unusual case of ependymoma with pigmentation, a phenomenon that has only been described in a few cases, to our knowledge. This tumor occurred in the fourth ventricle of a 45-year-old man. It showed the typical histologic appearance of ependymoma with perivascular pseudorosettes and rare ependymal rosettes. Some tumor cells contained brown cytoplasmic pigment, which was shown histochemically to represent a mixture of lipofuscin and neuromelanin. The pigment was positive for acid-fast and periodic acid-Schiff stains and was also focally positive for Masson-Fontana and Schmorl stains (bleached by pretreatment with potassium permanganate). In addition, some other tumor cells showed a signet ring morphology as a result of prominent intracytoplasmic vacuolation. Immunohistochemically, all the tumor cells expressed glial fibrillary acidic protein, and rare pigmented tumor cells also expressed HMB-45. Ultrastructural examination showed irregularly shaped heterogeneous electron-dense bodies corresponding to the pigment, and the cytoplasmic vacuoles were formed by dilatation of intracytoplasmic lumens lined by microvilli. Since lipofuscin production can occur in normal ependymal cells and neuromelanin has been suggested to be a melanized form of lipofuscin, it is not surprising that these 2 pigments can be found in ependymoma. In all the previously reported cases, the pigment was shown to represent melanin only. In our case, the HMB-45 positivity in rare tumor cells indicated that there might also be a minor melanin component in the pigment in addition to lipofuscin and neuromelanin.- - - - - - - - - - ranking = 7keywords = ependymoma (Clic here for more details about this article) |
8/37. association of meningioma and ependymoma--case report.We report the rare association of a meningioma and an ependymoma in a young boy. A meningioma was detected in the left cerebellopontine angle at age 8 months, and an ependymoma in the left frontal lobe 2 years later. Chromosomal analysis was normal, and his family showed no signs of phacomatosis. Both tumors were totally removed, and he recovered well after both operations.- - - - - - - - - - ranking = 6keywords = ependymoma (Clic here for more details about this article) |
9/37. Intratumoral abscess: an unusual complication of ventriculoperitoneal shunt infection.INTRODUCTION: Ventriculoperitoneal shunts were routinely used in the past in children with posterior fossa tumors and hydrocephalus. They can, however, cause a multitude of problems. CASE REPORT: This report highlights a previously unencountered phenomenon of a pyogenic abscess forming within a posterior fossa ependymoma as a result of shunt infection. The shunt was exteriorized and the child treated with antibiotics before surgery was done. Only a partial excision of the tumor was possible, as the inflammatory response caused by the abscess had obliterated tissue planes.- - - - - - - - - - ranking = 1keywords = ependymoma (Clic here for more details about this article) |
10/37. Primary intracranial myxopapillary ependymomas: report of two cases and review of the literature.Myxopapillary ependymoma is a variant of ependymoma occurring almost exclusively in the conus medullaris or filum terminale. Myxopapillary ependymoma found primarily in the brain is extremely rare. Two such cases appearing at the 4th ventricle and cerebral falx are reported. The imaging features of such tumors are a primary cystic mass with strong enhancement at its solid part. Myxopapillary ependymoma should be a possible differential diagnosis when an intracranial cystic tumor is found.- - - - - - - - - - ranking = 8.427182078889keywords = ependymoma, myxopapillary (Clic here for more details about this article) |
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