1/65. 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 = 1keywords = nervous system (Clic here for more details about this article) |
2/65. The tanycytic ependymoma of the lateral ventricle: case report.The tanycytic ependymoma is an extremely rare, primitive neuroectodermal tumor, arising from the ependymoglial cells or tanycytes. Such cells are generally seen in the primitive nervous system instead of the mature ependymal cells. The tanycytic ependymoma described in this report was found in a 42-year-old man. Histological analysis strongly suggested that this tumor originated from a primitive progenitor cell, the ependymoglia or the tanycyte in the lateral ventricle.- - - - - - - - - - ranking = 1keywords = nervous system (Clic here for more details about this article) |
3/65. Sacrococcygeal extraspinal ependymomas: the role of coccygectomy.BACKGROUND: Ependymomas, the common glial tumors of the spinal cord, occur occasionally outside the central nervous system and are called exstraspinal ependymomas (EEP). EEPs are found primarily in sacrococcygeal region during childhood. The pathogenesis and the treatment of the sacrococcygeal (SC) ependymomas are still controversial. Therefore, we present our case with metaanalysis of other case reports to determine the optimal treatment modality for SC EEPs. methods: A metaanalysis of case reports of SC EEPs, including the current case, was conducted. Also all available case reports of EEPs, without age limit, were analyzed to determine the distribution of EEPs localization. RESULTS: EEPs usually are found in teratoma localizations such as the SC area, ovary, paraovarian structures, and medastinum. The distribution of EEPs localization differs with age. Local recurrence rate of EEPs after coccyx excision is zero, however, it increases to 71% when the coccyx was left behind. CONCLUSION: The identical clinical characteristics of the SC teratomas and EEPs imply that the SC EEPs may be monophasic teratomas as their ovarian counterparts are named. coccyx excision is an important part of the surgical treatment of these tumors, with an apparent decrease in the recurrence rate.- - - - - - - - - - ranking = 1keywords = nervous system (Clic here for more details about this article) |
4/65. Primary intradural extramedullary ependymoma: case report and review of the literature.STUDY DESIGN: The authors report the ninth case in the literature of a primary intradural extramedullary ependymoma of the spinal cord. OBJECTIVE: To discuss surgical treatment and the physiopathologic hypothesis of this localization on the basis of the results of the present study and a review of the literature. SUMMARY OF BACKGROUND DATA: ependymoma is a glial tumor known to arise in the central nervous system. Intradural extramedullary location of this neoplasm has been exceptionally described previously. methods: A 43-year-old woman was admitted to the authors' institution with an history of progressive paraplegia. neurologic examination showed sensory loss below T1 and bladder disturbances. magnetic resonance imaging revealed an enhanced thoracic intradural extramedullary tumor, extending from T1-T8. No other lesion in the central nervous system was found. Emergency surgical resection was performed. RESULTS: Surgery gave confirmation of an encapsulated extramedullary tumor without attachment to the spinal cord or to the dura mater. Total removal was achieved under microscope. The postoperative course was uneventful, with complete neurologic recovery 3 months later. The patient has been well for 24 months of follow-up evaluation, without evidence of recurrence on magnetic resonance images. Histologic examination revealed the tumor as a benign ependymoma. CONCLUSION: The encapsulated feature, the lack of attachment to the central nervous system, and the absence of other neoplastic processes within the brain or the spinal cord suggested that this lesion is a primary tumor developed from ectopic ependymal cells.- - - - - - - - - - ranking = 3keywords = nervous system (Clic here for more details about this article) |
5/65. Spinal tanycytic ependymomas.Three cases of spinal tanycytic ependymoma are reported, a man aged 45 years and two women aged 36 and 55 years. Each patient developed gradual paraparesis over a few months prior to admission. magnetic resonance imaging showed an enhancing, well-circumscribed tumor in the spinal cord in each case. Histologically, the tumors consisted of monotonous proliferation of long spindle cells with markedly eosinophilic cell processes; focally forming perivascular pseudorosettes. The tumor cells were strongly immunopositive for glial fibrillary acidic protein, S-100 protein and vimentin. Ultrastructurally, in addition to massive intermediate filaments, many tumor cells showed abundant microtubules. Well-developed desmosomes and microvilli/cilia-lined microlumina were occasionally observed. The tumors were grossly totally removed and the patients remain recurrence free at 9, 9, and 2 years postoperatively. Reviewing reported cases including our three cases, tanycytic ependymoma may occur frequently in spinal cord, especially in the cervical region of the spinal cord. Since histologically it resembles pilocytic astrocytoma and schwannoma, tanycytic ependymoma should be included in the differential diagnosis of benign spindle cell tumors of the central nervous system.- - - - - - - - - - ranking = 1keywords = nervous system (Clic here for more details about this article) |
6/65. Intraoperative diagnosis of tanycytic ependymoma: pitfalls and differential diagnosis.Smear preparations have become increasingly popular in the intraoperative assessment of central nervous system pathology. The cytological features of a histologically proven tanycytic ependymoma are presented with the pitfalls and differential diagnosis. The smear preparation showed a glial neoplasm composed of cells with long, bipolar glial processes and oval to spindle-shaped nuclei resembling those seen in pilocytic astrocytoma smears. The smear characteristics of an ependymoma usually show remarkably uniform round-to-oval nuclei, fluffy glial processes, and a perivascular nuclear-free zone (pseudorosetting). None of these features were present in our case. The accompanying frozen section showed a fascicular spindle-cell tumor that resembled a schwanomma, a commonly reported misinterpretation of the histology of tanycytic ependymomas on frozen sections. Careful attention to the radiological findings, the surgeon's impression, and the intraoperative smear preparation details should allow one to include this uncommon entity in the differential diagnosis of spinal neoplasms.- - - - - - - - - - ranking = 1keywords = nervous system (Clic here for more details about this article) |
7/65. Imprint cytologic features of intracytoplasmic lumina in ependymoma. A report of two cases.BACKGROUND: Intracytoplasmic lumina have been recently recognized as a characteristic histologic feature of ependymoma. However, the cytologic diagnostic usefulness has not been discussed. We encountered two imprint cytology cases of spinal cord ependymomas in which there were intracytoplasmic lumina in the tumor cells. CASES: Two women had spinal cord tumors on magnetic resonance imaging. Imprint cytology study was carried out on the resected tumors. The cytologic specimen of the first case, aged 52, showed tumor clusters consisting of elongated epithelioid cells, a few of which also had intracytoplasmic lumina. Histologically, tumor cells formed ependymal rosettes and pseudoperivascular rosettes. There were a few tumor cells with intracytoplasmic lumina. The cytologic specimen of the second patient, aged 37, had scattered and isolated tumor cells with intracytoplasmic lumina resembling signet-ring cells and paired tumor cells forming small, glandlike structures. Histologically, the tumor was composed mainly of signet-ring-like cells containing intracytoplasmic lumina. CONCLUSION: Intracytoplasmic lumina were observed in the imprint cytologic specimens of spinal cord ependymoma. The diagnosis of ependymomas can be made cytologically when intracytoplasmic lumina are found since no other primary neuroepithelial tumors of the central nervous system possess such a characteristic feature.- - - - - - - - - - ranking = 1keywords = nervous system (Clic here for more details about this article) |
8/65. Intraosseous sacral myxopapillary ependymoma and the differential diagnosis of sacral tumors.Although involvement of other regions of the spinal cord and brain stem is seen, myxopapillary ependymoma is most commonly found at the filum terminale or cauda equina. Less commonly, myxopapillary ependymoma may occur outside the central nervous system from direct metastatic extension of an intrathecal tumor, and rarely it may present as a primary tumor outside the thecal sac. The authors present a case of primary sacral myxopapillary ependymoma, which was first diagnosed as a chordoma. They then discuss the magnetic resonance imaging findings of this and other sacral tumors. Myxopapillary ependymoma should be considered in the differential diagnosis for a primary expansile sacral mass along with other lesions such as chordoma, aneurysmal bone cyst, and giant cell tumor.- - - - - - - - - - ranking = 1keywords = nervous system (Clic here for more details about this article) |
9/65. choroid plexus papilloma diagnosed by crush cytology.In a 32-yr-old man, an infratentorial cystic lesion with a mural nodule was interpreted to be either a hemangioblastoma or a cystic astrocytoma on CT scan. Intraoperative crush cytology revealed it to be a choroid plexus papilloma (CPP). The utility of crush cytology in the rapid diagnosis of central nervous system (CNS) tumors and the differential diagnosis of CNS papillary lesions are highlighted in this report.- - - - - - - - - - ranking = 1keywords = nervous system (Clic here for more details about this article) |
10/65. Tumor imprint cytology of ovarian ependymoma. A case report.BACKGROUND: ependymoma is a tumor that usually develops in the central nervous system and is extremely rare in the ovary. The first case of ovarian ependymoma was reported by Kleinman et al. (Kleinman GM, Young RH, Scully RE. ependymoma of the ovary: report of three cases. Hum Pathol 1984;15:632-8.) in 1984, and only eight cases have been reported since then. Criteria for the histopathologic diagnosis of ependymoma are already established, but there has been no investigation of the cytologic diagnosis of ovarian ependymoma. methods: An imprint cytologic specimen was obtained from a recurrent ovarian ependymoma. The imprint cytologic features were compared with the findings of histologic examination, immunostaining, and electron microscopy. RESULTS: Imprint cytology revealed clusters of small cells with tapering cytoplasmic processes and a round nucleus. On the basis of these features, a neurogenic tumor could be included in the differential diagnosis. Furthermore, many rosette-like collections of cells that were suggestive of ependymal rosettes or perivascular pseudorosettes, characteristic of ependymoma, were found. The presence of ependymal rosettes and perivascular pseudorosettes also were confirmed by the histopathologic examination. Together with positive immunostaining for glial fibrillary acidic protein, this led to the diagnosis of ependymoma, which also was supported by the electron microscopic findings. CONCLUSIONS: Careful observation of the imprint cytologic specimen of an ovarian ependymoma should reveal numerous rosette-like collections of cells that were suggestive of ependymal rosettes or perivascular pseudorosettes. In addition, if we remember that ependymoma can develop in the ovary and find cells with tapering processes that suggest a neurogenic tumor, it may be possible to detect histologic features characteristic of ependymoma by the imprint cytology. To our knowledge, this is the first report on the imprint cytologic diagnosis of ependymoma originating in the ovary.- - - - - - - - - - ranking = 1keywords = nervous system (Clic here for more details about this article) |
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