Cases reported "Meningeal Neoplasms"

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1/15. Clear cell meningioma of the lumbo-sacral spine with chordoid features.

    Clear cell meningioma (CCM) is a peculiar variant that differs from conventional meningioma in affecting younger patients, arising more often in spinal or cerebellopontine locations, and showing a higher recurrence rate. Classical meningothelial areas are scarce in these tumors and the differential diagnosis with other neoplasms, particularly metastatic carcinoma, is often difficult. We report a case of clear cell meningioma from the lumbosacral spine in which location, radiologic presentation, light microscopic appearance in initial sampling, and some of the ultrastructural findings were reminiscent of chordoma. The tumor cells were diffusely positive for vimentin and very focally positive for epithelial membrane antigen. Ultrastructural demonstration of interdigitating cell processes joined by numerous desmosomes confirmed the diagnosis of CCM.
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2/15. meningioma of the fourth ventricle.

    Meningiomas are primary meningeal based tumors of the central nervous system that rarely are located strictly within the fourth ventricle. We report a 72-year-old man operated upon for such a tumor. The pre-operative magnetic resonance images revealed a well circumscribed mass in the fourth ventricle that exhibited a low signal on T1-weighted magnetic resonance images and homogenously enhanced with gadolinium. By light microscopy the tumor was composed of tightly packed spindle cells separated by collagen. immunohistochemistry showed the tumor cells to be positive for vimentin and epithelial membrane antigen, and negative for glial fibrillary acidic protein. Electron microscopy revealed typical findings of meningioma, including interdigitating cell processes, desmosomes, and intermediate filaments. Although rare, fibroblastic meningioma must be included in the differential diagnosis of a fourth ventricular spindle cell tumor in elderly patients.
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3/15. meningioma with granulofilamentous inclusions.

    The authors report a case of intracranial meningioma with granulofilamentous inclusions. A 50-year-old man had right trigeminal neuralgia due to trigeminal nerve compression by a petroclival tumor and received tumor resection. Microscopically, tumor cells containing eccentric nuclei and intracytoplasmic hyaline inclusions were arranged in sheets and whorls. The inclusions were negative for periodic acid-schiff reaction. No histological anaplasia was seen. immunohistochemistry showed epithelial membrane antigen reactivity on the cytoplasmic membrane. Immunoreactivity for vimentin was recognized in cytoplasm adjacent to inclusions. However, confocal laser microscopic study revealed immunoreactivity for vimentin even inside some inclusions. Ultrastructurally, interdigitation of cytoplasmic processes and desmosomes connecting adjacent cells were noted. Inclusions were composed of numerous fine osmiophilic granules attached by intermediates filaments. These findings were consistent with a meningioma with the granulofilamentous inclusions described earlier. The findings demonstrated by confocal laser microscopy and electron microscopy suggest that these granular materials may be the metabolic products of vimentin filaments.
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4/15. Ultrastructural examination is essential for diagnosis of papillary meningioma.

    AIMS: Papillary meningioma is a rare meningeal tumour. To date only a few cases have been reported and their immunohistochemical features have not been fully documented. methods AND RESULTS: A 49-year-old woman presented with a 2-month history of headaches and memory disturbance. CT and MRI imaging showed an enhancing pineal mass with extension into the occipital lobes and invasion of the splenium. At surgery, the tumour was found to be tough and vascular with a well-defined capsule. No recurrence was noted 19 months after the operation. In another case a 44-year-old woman was admitted with 1-month history of headaches, poor memory, imbalance and diplopia. CT scan showed a large hyperdense, uniformly, enhancing mass within the middle cranial fossa at the petrous ridge. The tumour recurred 19 and 25 months after first resection. The histology of both tumours was similar. The neoplasms contained polygonal cells with a moderate amount of cytoplasm, rounded regular nuclei and distinct cell borders. The cells were arranged radially around the blood vessels (perivascular pattern) and a papillary pattern was seen only focally. Mitotic figures were moderately frequent. immunohistochemistry showed that both tumours were immunoreactive to vimentin and NSE, whereas GFAP, CAM5.2, EMA, S100 protein and synaptophysin were negative. Electron microscopy revealed interdigitating cell processes, desmosomes and intermediate filaments. CONCLUSIONS: The histological and immunohistochemical features of these two tumours are complex and difficult to interpret. Although papillary meningiomas were considered in our initial differential diagnosis, the final conclusion was possible only when the ultrastructural features were revealed.
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5/15. Meshy meningioma: a potential novel variant.

    A potential novel variant of meningioma is reported. The tumor was solid, hard, white-colored, well circumscribed in a fibrous capsule and fixed to the dura, showing no invasion into the brain parenchyma. Histopathological study presented a sparsely cellular tumor composed of cells with fine reticular or mesh-like cytoplasm, each containing an oval nucleus. Mitotic figures were rarely seen. Immunohistochemical studies of tumor cells showed positive immunoreactivity for vimentin and epithelial membrane antigen but were negative for GFAP, desmin, neurofilament, keratin, S-100, CD34 and CEA. Bipolar neoplastic cells and long processes were noted on ultrastructural observation; these were attached side by side to each other by desmosomes, resulting in a mesh-like configuration. Perinuclear cytoplasm and processes were rich in intermediate filaments and rough endoplasmic reticulum. These microscopic and ultrastructural features have never before been reported among the variants of meningioma. The name 'meshy meningioma' is proposed for this novel variant.
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6/15. Fibrous meningeal tumours with extensive non-calcifying collagenous whorls and glial fibrillary acidic protein expression: the whorling-sclerosing variant of meningioma.

    Meningiomas comprise a wide range of morphological patterns. We describe unusual fibrous meningeal tumours in two patients, composed of extensive non-calcifying collagenous whorls of varying size, resembling non-calcified psammoma bodies, while interposed tumour cells are sparse. immunohistochemistry showed expression of S-100, vimentin and glial fibrillary acidic protein, whereas only single tumour cells stained for epithelial membrane antigen. Electron microscopy detected desmosomes or desmosome-like structures in both specimens. We conclude that these tumours represent a peculiar whorling-sclerosing variant of fibrous meningioma. Recognition of this meningioma variant is important in the differential diagnosis of meningioma versus other fibrous tumours of the meninges, including solitary fibrous tumours of the meninges, unusual forms of desmoplastic gliomas or chondroid tumours.
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7/15. Cystic meningioma with unusual histopathological features.

    A parasagittal meningioma of an eighty year old female patient showed by light and electron microscopy cystic architecture (forme humide) as well as nuclear vacuoles (indentations) and cytoplasmic inclusions. The latter are the known pseudopsammoma bodies or hyaline inclusions as demonstrated by light and electron microscopy. light microcopy on paraffin sections and cytological smear preparations revealed, in addition to the cells of endotheliomatous meningioma and those containing the inclusions a third type with small granular cytoplasmic content. Electron microscopy showed characteristic features of meningioma such as folded double membranes, desmosomes and filaments and thus gave evidence of the meningiomatous nature of the tumor. By immunohistochemistry tumor cells in slightly focal distribution contained vimentin, whereas small clusters of cells with hyaline inclusions were strongly positive for cytokeratin. The dispersed cells of granular cytoplasmic content were positive for fibronectin. These findings, especially of the inclusion containing cytokeratin positive cell clusters may shed new light upon the concept of histogenesis and classification.
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8/15. hemangiopericytoma of the meninges of the optic nerve. A clinicopathologic report including electron microscopic observations.

    A 61-year-old man complained of visual loss of his right eye following a systemic viral illness. At this time, complete ophthalmologic examination failed to disclose any abnormalities. Over the next months the patient developed dramatic loss of vision. Extensive workup, including CT scans, failed to clarify the underlying cause and a diagnosis of optic atropy following optic neuritis was made. The patient remained asymptomatic, but repeated CT scans depicted a fusiform enlargement of the intraorbital portion of the right optic nerve, three years after the onset of visual loss. The presumptive clinical diagnosis was optic nerve meningioma and the tumor was removed via a Kronlein procedure. Histopathologically, a highly vascularized intradural mass that led to compression atrophy of the optic nerve was present. The tumor was composed of fascicles of spindle-shaped cells that were interspersed among numerous, irregular vascular channels. Electron microscopically, the cells disclosed a lucent cytoplasm with a scarcity of organelles, prominent cytoplasmic filaments, numerous micropinocytotic vesicles and subplasmalemmal linear densities (hemidesmosomes). Poorly developed intercellular junctions were present between interdigitating cytoplasmic processes. The tumor cells surrounding the vascular units displayed a continuous basement membrane as well as all the features of well-differentiated pericytes. Away from vascular structures some tumor cells, which showed a focally discontinuous basement membrane, exhibited intermediate features between pericytes and fibroblasts. To the best of our knowledge, this is the first report of a hemangiopericytoma arising from the meninges of the optic nerve.
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9/15. Intracellular inclusions in meningothelial meningioma. A histochemical and ultrastructural study.

    This is a study on the histochemical and electron microscope findings of the intracellular inclusions in a case of meningothelial meningioma of the frontoethmoidal region with orbital involvement. The inclusions are PAS-positive, diastase resistant, and stain strongly positive with the modified Morel-Sisley reaction for protein-bound tyrosine and weakly with dihydroxy-dinaphthyl-disulfide (DDD) for the demonstration of sulfhydryl (SH) and disulfide (S-S) groups of proteins. These staining reactions suggest the inclusions are composed of conjugated proteins (glycoproteins). Ultrastructurally, the inclusions are located within intracellular spaces lined by microvilli and are composed of granular material, usually forming a dense core that is intermixed with small vacuoles. Numerous desmosomes and whorls of tonofibrils are concentrated around them. Our findings support the view that the intracellular inclusions, which are rarely found in meningiomas, represent an active secretory product of the meningothelial cells rather than a degenerative or phagocytic process.
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10/15. Microcystic meningioma. Clinicopathologic report of eight cases.

    We report herein eight cases of microcystic meningiomas. This unusual variant was originally described by Masson, who labeled it "humid." Grossly, tumors were usually soft, with occasionally a glistening cut surface. Two tumors were cystic and three invaded bone structures. By light microscopy, tumor cells were stellate, with long processes delimitating clear spaces. Whorls were found in all tumors. Intracytoplasmic glycogen, fatty droplets, and phosphotungstic acid-hematoxylin-positive fibrils were sometimes seen. Tumor cells, however, were all negative with the peroxidase-antiperoxidase technique for glial fibrillary acidic protein. Mitoses, hemorrhages, and necrosis were absent. By electron microscopy, interdigitations of cytoplasmic processes and desmosomes were found. The large extracellular spaces were filled with a finely granular substance intermingled with fibrils and collagenic fibers. The clinical and morphological findings point toward a benign course. We also discuss the differential diagnosis and the pathogenesis.
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