1/90. 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.- - - - - - - - - - ranking = 1keywords = membrane (Clic here for more details about this article) |
2/90. Metastatic meningioma in fine-needle aspiration (FNA) of the lung: cytomorphologic finding.Pulmonary metastasis of intracranial meningioma is rare. We present the cytomorphologic features of such a tumor in a 71 yr-old woman who was found to have multiple lung nodules 13 years following the resection of an atypical intracranial meningioma. Cytomorphologic features were quite distinct and included hypercellularity with large syncytial groups of monomorphic cells with epithelioid morphologic features, often in perivascular arrangements. Occasional intranuclear cytoplasmic inclusions as well as binucleated cells with wispy cytoplasmic extensions were also noted. Immunoperoxidase studies showed focal positivity for epithelial membrane antigen. The differential diagnosis includes primary or metastatic adenocarcinoma, malignant mesothelioma, and melanoma.- - - - - - - - - - ranking = 1keywords = membrane (Clic here for more details about this article) |
3/90. Secretory meningioma of the brain. Report of two cases.Two cases of cerebral secretory meningioma, occurring in 57 and 33-year-old females are reported. The tumors were located in the tentorial and frontotemporal region, respectively. The general histologic appearance of the tumors was of meningothelial meningioma (case 1) and meningioma with microcystic and angiomatous features (case 2). The most striking histological finding in both tumors were numerous pseudopsammoma bodies, localized chiefly around blood vessels. The inclusions were slightly eosinophilic, stained strongly with PAS method and were differing in size from 3 to 30 microns. Tumor cells containing or surrounding pseudopsammomas were immunopositive for cytokeratin and epithelial membrane antigen. In the first case, individual pseudopsammomas were strongly positive for carcinoembryonic antigen. Some diagnostic aspects of this antigen and problems regarding differential diagnosis in secretory meningioma are briefly discussed.- - - - - - - - - - ranking = 1keywords = membrane (Clic here for more details about this article) |
4/90. Microcystic meningioma arising in a mixed germ cell tumor of the testis: a case report.We report a case of a microcystic variant of meningioma arising in a mixed germ cell tumor of the testis composed predominantly of mature and immature teratoma with elements of seminoma and embryonal carcinoma. We believe this is the first such case of a meningioma arising in a teratoma within a gonadal or extragonadal site. The meningiomatous component showed positive immunohistochemical staining for epithelial membrane antigen and a lack of staining for cytokeratin, factor viii, CD31, and alpha-fetoprotein. Recognition of a non-germ cell tumor arising in the setting of a teratoma in the testis may be prognostically important depending on the nature of the non-germ cell component and whether it has spread beyond the testis.- - - - - - - - - - ranking = 1keywords = membrane (Clic here for more details about this article) |
5/90. 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.- - - - - - - - - - ranking = 1keywords = membrane (Clic here for more details about this article) |
6/90. Intranuclear inclusions of meningioma associated with abnormal cytoskeletal protein expression.We describe a case of meningothelial meningioma with a large number of intranuclear inclusions. Morphologically, these are divided into cytoplasmic inclusions and nuclear vacuoles. The cytoplasmic inclusion has a limiting membrane with cell organelles and filaments. Inclusions of this type are generally eosinophilic, like the cytoplasm. However, there are many inclusions that are more eosinophilic than the cytoplasm or that have a ground-glass appearance. Some of them may contain fine or coarse granules. On the other hand, the nuclear vacuole lacks a limiting membrane and appears empty. In most of the inclusions of this type, there is a faintly basophilic substance in the margin. Generally, the cytoplasmic inclusions are as immunopositive as cytoplasm with vimentin, but some of these cytoplasmic inclusions are more reactive. Under the electron microscope, abnormal aggregation of intermediate filaments is recognized in the cytoplasmic inclusions. It is considered that a strong reaction of cytoplasmic inclusions with vimentin immunostaining is due to abnormal aggregation of intermediate filaments. The present study distinctly demonstrates abnormal localization of intermediate filaments in the cytoplasmic inclusions, and it is suggested that the cytoskeleton participates in the evolution of the cytoplasmic inclusions.- - - - - - - - - - ranking = 2keywords = membrane (Clic here for more details about this article) |
7/90. Lateral ventricular meningioma encapsulated by the dura-like membrane.The first case of a ventricular meningioma that was encapsulated by the dura-like membrane is reported. magnetic resonance imaging (MRI) showed a heterogeneous mass with a low intensity rim in the trigone of the right lateral ventricle of a 63-year-old male. Histological examination revealed that the tumor was a transitional meningioma encapsulated by a thick dura-like membrane. Moreover, abundant clusters of the dura-like connective tissue existed in the tumor, indicating that both the dura-like capsule and the dura-like clusters in the tumor were created by the tumor cells.- - - - - - - - - - ranking = 6keywords = membrane (Clic here for more details about this article) |
8/90. Sporadic unilateral vestibular schwannoma with islets of meningioma: case report.OBJECTIVE AND IMPORTANCE: Vestibular schwannomas with meningioma islets have been rarely reported in the literature; they have been observed only among patients with neurofibromatosis Type II. We present a case of a sporadic mixed tumor in a patient without neurofibromatosis Type II that was not suspected before surgery. CLINICAL PRESENTATION: A 59-year-old female patient presented with clinical signs of progressive loss of hearing. Her family history did not include evidence of neurological diseases. magnetic resonance imaging scans revealed a typical unilateral vestibular schwannoma. INTERVENTION: The tumor presented with invasion of the surrounding arachnoid membrane, as well as cranial nerves VII and VIII. Preservation of the facial nerve with complete removal of the tumor was not possible. Therefore, Cranial Nerve VII reconstruction was performed. CONCLUSION: The concomitant occurrence of schwannomas and meningiomas infiltrating the arachnoid membrane might be related to poor clinical outcomes for patients with neurofibromatosis Type II, with respect to preservation of facial and acoustic nerves. Among sporadic schwannomas, this phenomenon is extremely rare.- - - - - - - - - - ranking = 2keywords = membrane (Clic here for more details about this article) |
9/90. Primary extracranial meningioma of the foot: a case report.We present a rare case of primary extracranial meningioma in a 36-year-old man, who had a solitary multinodular mass located in the plantar muscle of the foot. The histology of specimens from simple excision was typical of meningioma, showing bland spindle cell proliferation with a whorl pattern. Immunohistochemical analysis demonstrated that the tumor cells showed diffuse and strong positivity for epithelial membrane antigen as well as moderate reactivity for cytokeratin and vimentin. Ultrastructurally, the tumor cells were characterized by thin bipolar cytoplasmic processes and joined by multiple small desmosomes. There were frequent pinocytotic vesicles and a distinct external lamina on the cell surface. These findings suggest that this primary ectopic meningioma, arising in the soft tissue, may have been derived from perineurial cells of the peripheral nerve, but was morphologically distinguishable from perineurioma. Primary extracranial meningioma should be included in the differential diagnosis of soft-tissue spindle cell tumors, especially those of peripheral nerve origin.- - - - - - - - - - ranking = 1keywords = membrane (Clic here for more details about this article) |
10/90. 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.- - - - - - - - - - ranking = 2keywords = membrane (Clic here for more details about this article) |
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