1/153. Benign schwannoma of the digestive tract: a clinicopathologic and immunohistochemical study of five cases, including a case of esophageal tumor.We report five cases of schwannomas of the digestive tract. The patients were two men and three women, whose ages ranged from 56 to 74 years. Three cases arose in the stomach, one in the ascending colon, and one in the esophagus; the latter was a hitherto unreported location for this tumor. The schwannomas ranged from 2 to 11 cm in diameter. They were well circumscribed but not encapsulated, with interlacing bundles of spindle cells, nuclear atypia and no mitosis, interspersed with collagenous strands. Inflammatory cells were scattered throughout the tumors and a peripheral cuff of lymphoid aggregates was observed in all cases. Intracellular periodic acid-Schiff (PAS)-positive crystalloids were found in three cases; no skeinoid fibers were seen. A diffuse and intense positivity for vimentin and S-100 protein was detected in all five cases together with a variable and sometimes focal positivity for glial fibrillary acidic protein and neuron-specific enolase. None of the tumors showed expression of CD34 or the smooth muscle antigens tested. The four cases with a sufficient follow-up had a favorable outcome without any recurrence or metastasis. The morphologic and immunohistochemical features of digestive schwannomas were compared with those of other gastrointestinal stromal tumors. Schwannomas have many differences. Digestive schwannomas can be readily recognized on histologic and immunohistochemical examination. They are spindle cell tumors without epithelioid features, with a peripheral cuff of lymphoid tissue. Specific intracellular needle-shaped PAS-positive crystalloids are found in some cases, whereas skeinoid fibers are not. These tumors always express S-100 protein in a diffuse and strong manner, and they express glial fibrillary acidic protein but not express CD34. Digestive schwannomas usually are gastric tumors and have never been reported in the small bowel. They pursue a benign course and are far rarer than gastrointestinal autonomic nerve tumors.- - - - - - - - - - ranking = 1keywords = spindle cell, spindle (Clic here for more details about this article) |
2/153. ciliary body schwannoma.PURPOSE: Intraocular schwannomas are very rare, benign, peripheral nerve neoplasms. The authors report a case of ciliary body schwannoma. METHOD: A 39-year-old Korean woman presented with slowly decreasing visual acuity and proptosis of the right eye for 4 years. At the time of her visit, the eyeball protruded and deviated laterally. She could not sense light with her right eye. We enucleated the eyeball. The enucleated eyeball with tumor was examined histopathologically, immunohistochemically, and under electron microscope. RESULTS: Microscopic examination revealed spindle cells and characteristic Antoni type A and B areas with Verocay bodies. Immunohistochemical study showed tumor cell expressions of S-100 and vimentin, but other immunohistochemical studies were negative. Electron microscopic examination demonstrated Luse body. CONCLUSIONS: We diagnosed the tumor as a schwannoma arising from the ciliary body on the basis of the above mentioned results. Schwannomas are very rare intraocular neoplasms, but they are benign so we should differentiate from other intraocular neoplasms.- - - - - - - - - - ranking = 0.5keywords = spindle cell, spindle (Clic here for more details about this article) |
3/153. Intramedullary melanotic schwannoma. Report of a case and review of the literature.A case of an intramedullary melanotic schwannoma located in the spinal cord at the T2-T3 level is described. The lesion occurred in a 44-year-old woman with a 10-year history of weakness and sensory numbness in both legs and feet. At operation the lesion appeared as a well-demarcated grey-brown intramedullary mass. Histologically, it was composed of interlacing bundles of spindle cells showing their cytoplasm filled with melanin. Among spinal cord neoplasms, melanotic schwannomas are rare tumours, which have apparently been reported only in three previous instances. The clinical, diagnostic and pathological features, as well as the possible aetiology of these rare tumours are discussed.- - - - - - - - - - ranking = 0.5keywords = spindle cell, spindle (Clic here for more details about this article) |
4/153. The clinical spectrum of schwannomas presenting with visual dysfunction: a clinicopathologic study of three cases.Schwannomas (neurilemomas) are benign tumors that arise from schwann cells in the peripheral nervous system. The most commonly involved nerves that cause neuro-ophthalmic manifestations are cranial nerves V and VIII. In this series of three women, schwannomas presented as intraconal masses that mimicked a cavernous hemangioma, a superior orbital mass transgressing the superior orbital fissure, and an expansive frontal lobe mass with clinical symptoms and signs of increased intracranial pressure. Although all three complained of visual blurring, none of our patients presented with Vth or VIIIth cranial nerve dysfunction. Histopathologic studies demonstrated well-circumscribed, encapsulated spindle-cell lesions with classic Antoni A and B patterns. Histopathologic examination is essential to confirm the diagnosis of a schwannoma that may be otherwise clinically confusing. Direct optic nerve compression, globe indentation with induced hyperopia, or increased intracranial pressure with optic nerve compromise may be responsible for visual symptoms. A multidisciplinary approach is often required because of the size and location of schwannomas.- - - - - - - - - - ranking = 0.12771503641533keywords = spindle (Clic here for more details about this article) |
5/153. Benign schwannoma of the esophagus removed by enucleation: report of a case.A submucosal tumor of the esophagus was enucleated by a thoracotomy. A microscopic examination showed the tumor to be composed of spindle-shaped cells showing mild nuclear atypia with vague nuclear palisading and scarce mitotic figures. The tumor was surrounded by peripheral lymphoid cuffs. An immunohistochemical study demonstrated diffuse positive staining for S-100 protein in the tumor cells. The lesion was diagnosed to be an esophageal schwannoma based on these pathological features. Benign schwannoma of the esophagus has been described in five cases in four reports in the English literature. This is the sixth case diagnosed by immunohistochemical studies.- - - - - - - - - - ranking = 0.12771503641533keywords = spindle (Clic here for more details about this article) |
6/153. Pleomorphic hyalinizing angiectatic tumor of soft parts: immunohistochemical study including the expression of vascular endothelial growth factor.We report morphologic, flow cytometric, and immunohistochemical findings in two cases of pleomorphic hyalinizing angiectatic tumor of soft parts. Both patients were middle-aged women with subcutaneous lesions located in the lower extremity. The tumors consisted of sheets of spindled and pleomorphic cells with frequent intranuclear pseudoinclusions associated with clusters of ectatic vessels surrounded by prominent perivascular hyaline material. Numerous, nonhyalinized vessels were also present, mostly in the peripheral areas of the lesions. Some of these vessels had their walls permeated by numerous small capillaries. Immunostaining for vascular endothelial growth factor (VEGF), a secreted protein that has been implicated in tumor-associated angiogenesis, demonstrated positive staining in both tumoral and endothelial cells. Tumor cells were also reactive to vimentin and CD34. Focal positivity for CD99 and factor xiiia was also present. flow cytometry yielded a diploid dna histogram with S-phase fraction of 7%. Our findings corroborate those from previously reported cases. They further suggest that angiogenesis and the angiogenic factor VEGF may play a role in the development of this peculiar tumor.- - - - - - - - - - ranking = 0.12771503641533keywords = spindle (Clic here for more details about this article) |
7/153. Choroidal schwannoma: immunohistochemical and electron-microscopic study.Schwannoma (neurilemoma) arising from the ciliary body and choroid is a rare form of intraocular tumor and usually misdiagnosed clinically as amelanotic melanoma. This case report describes a 73-year-old woman who developed a large nonpigmented intraocular tumor of the choroid in the left eye and underwent enucleation with a clinical diagnosis of malignant melanoma. The tumor consisted of spindle-shaped cells with an indefinite cytoplasm and twisted nuclei, which had positive immunoreactivity for S-100 protein, vimentin, glial fibrillary acidic protein and neural cell adhesion molecule. A continuous basal lamina encompassing the tumor cells was demonstrated by immunostaining for laminin and type IV collagen. Ultrastructurally, tumor cells with scant organelles had delicate cytoplasmic processes apposing each other, all indicative of Schwann cell origin. In reexamination of fluorescein angiograms, ultrasonograms and magnetic resonance images, no findings were incompatible with a diagnosis of choroidal melanoma. Histopathological studies showed that the tumor was a schwannoma. At present, we do not have a benchmark for the clinical diagnosis of intraocular schwannoma.- - - - - - - - - - ranking = 0.12771503641533keywords = spindle (Clic here for more details about this article) |
8/153. Malignant peripheral nerve sheath tumor arising in benign ancient schwannoma: a case report with an immunohistochemical study.A rare example of malignant transformation in an ancient schwannoma arising in the right side of the neck of a 51-year-old man without any clinical manifestations suggesting neurofibromatosis is described. The tumor, approximately 4 cm at its largest dimension, was well circumscribed and had a direct connection with the sympathetic nerve. Microscopically, the central portion of the tumor showed features of ancient schwannoma characterized by extensive hyalinization with cystic degeneration, scattered spindle cells with hyperchromatic and tapered nuclei, and some symplastic changes. However, predominantly in the outer portion, a proliferation of spindle-shaped cells with enlarged nuclei was present. The nuclei of these cells showed irregular contours, coarse granular chromatin texture, and conspicuous nucleoli. Mitotic figures and small necrotic foci with scattered apoptotic bodies were also seen. Immunohistochemically, S-100 protein was almost negative in areas consisting of overtly atypical cells where the mitotic index evaluated with MIB-1 antibody was 30.5%. In contrast, S-100-positive bland spindle cells were scattered in an extensively hyalinized area with a labeling index less than 3%. P53 protein was strongly positive in atypical spindle cells. Although it is a very uncommon event, definite nuclear atypia, frequent mitotic figures, and the existence of small necrotic foci should be recognized as indicating a diagnosis of malignant degeneration of benign schwannoma. immunohistochemistry would be useful as an ancillary technique in such a setting.- - - - - - - - - - ranking = 1.6277150364153keywords = spindle cell, spindle (Clic here for more details about this article) |
9/153. Benign esophageal schwannoma: report of a case.We report herein the case of an otherwise asymptomatic 62-year-old woman who was found to have an incidental esophageal lesion during endoscopic follow-up of an unrelated disorder. An esophageal submucosal tumor was diagnosed, and the patient was subsequently monitored on a regular yearly basis. As the diameter of the tumor doubled over a 4-year period, the possibility of a malignant lesion could not be excluded, and she was admitted to our hospital for further investigations. Esophagography, endoscopy, endoscopic ultrasonography, and computed tomography confirmed a submucosal tumor, 35 mm in length, in the thoracic midesophagus. A leiomyoma or leiomyosarcoma was suspected based on the known incidence of such tumors, and tumor enucleation was performed. Gross inspection revealed a solid tumor arising from the wall of the esophagus. Histopathologic examination showed intertwined bundles of spindle cells with spiral-like proliferation, and immunohistochemical studies were positive for S-100 protein, whereby a diagnosis of esophageal schwannoma was established. The patient experienced no postoperative complications, and her clinical course to date has been satisfactory. To date, 2 years 8 months after surgery, she has shown no sign of tumor recurrence and remains in good health.- - - - - - - - - - ranking = 0.5keywords = spindle cell, spindle (Clic here for more details about this article) |
10/153. Primary intracranial malignant schwannoma of trigeminal nerve. A case report with review of the literature.The authors report a rare case of primary intracranial malignant schwannoma of the trigeminal nerve occuring in a 30-year-old woman without von Recklinghausen's neurofibromatosis (VRNF). The tumour arose from the intracranial part of the left trigeminal nerve, without skull base destruction. The tumour was partially removed operatively, followed by focal 50 Gy irradiation, but unfortunately the tumour showed rapid regrowth. A second operation was attempted, but she died of cerebral infarction soon after operation. Histologically, the original tumour was characterized by the presence of foci of extremely high cellularity, pleomorphism and mitosis in an otherwise typical benign schwannoma. Immunohistochemically, the tumour cells were positive for S-100 protein even in the atypical areas, suggesting the tumour to be of Schwann cell origin. However, the recurrent tumour was composed of undifferentiated spindle cells, which were negative for S-100 protein. Thus, it is possible to consider that the S-100 protein expression could reflect the degree of differentiation of schwann cells. Furthermore, the postoperative irradiation might have exacerbated the malignant progression in the present case.- - - - - - - - - - ranking = 0.5keywords = spindle cell, spindle (Clic here for more details about this article) |
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