1/60. Midline cerebellar cystic schwannoma : a case report.An extremely unusual case of a cystic schwannoma in the region of the inferior vermis and posterior to the fourth ventricle in a fifteen year old boy is reported. The cystic tumour caused partial obstruction to the outflow of cerebrospinal fluid from fourth ventricle and resulted in development of supratentorial hydrocephalus. On investigations, the schwannoma simulated a Dandy-Walker cyst. The boy presented with symptoms of increased intracranial pressure. On surgery, the lesion was not arising from any cranial nerve, nor was it attached to brain parenchyma, blood vessel or to the dura. The possible histogenesis of the cystic schwannoma in a rare location is discussed.- - - - - - - - - - ranking = 1keywords = blood vessel, vessel (Clic here for more details about this article) |
2/60. 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 = 0.59975666016462keywords = vessel (Clic here for more details about this article) |
3/60. Laparoscopic resection of a retroperitoneal schwannoma.Although laparoscopic surgery for retroperitoneal diseases has been widely performed, there are few reports of laparoscopic resection for retroperitoneal tumors. We present the case of a 5-cm retroperitoneal tumor compressing the right common iliac vein and inferior vena cava that was successfully resected using a laparoscopic technique. dissection between the tumor and the large vessels was performed safely using a harmonic scalpel and an ultrasonic surgical aspirator. Histopathology of the resected tumor showed a benign schwannoma. Laparoscopic surgical techniques should be considered for treatment of selected retroperitoneal tumors.- - - - - - - - - - ranking = 0.19991888672154keywords = vessel (Clic here for more details about this article) |
4/60. Degenerated neurilemoma (ancient schwannoma).We report a case of degenerated neurilemoma in a 65-year-old Japanese woman. A tumor in the right thigh histopathologically showed a mixture of Antoni type A and B patterns, and contained prominent blood vessels with hyalinized walls, but no calcification. The tumor cell nuclei of middle areas were large, hyperchromatic and often multilobed but lacked mitotic figures. The mucinous areas had few tumor cells. Antoni type A and B areas were S-100 protein positive, while mucinous areas and hyalinized vessels were negative.- - - - - - - - - - ranking = 1.1999188867215keywords = blood vessel, vessel (Clic here for more details about this article) |
5/60. Mediastinal neurilemmoma complicated with spinal subarachnoid hemorrhage.A 28-year-old woman suffered severe back pain and headache during exercising on three occasions during the prior two-month period. On admission, the physical examination revealed symptoms of meningeal irritation, nuchal rigidity, severe headache, continuous nausea, and vomiting. Cerebral computed tomography of the intracranial subarachnoidal space revealed no subarachnoid hemorrhage. Her cerebrospinal fluid was bloody. Spinal magnetic resonance imaging identified a posterior mediastinal tumor adherent to the left side of the 5th thoracic vertebra and an abnormally expanded blood vessel near the mediastinal tumor. In addition, a high signal intensity lesion appeared to be present on the surface of the spinal cord. A mediastinal neoplasm was removed through standard thoracotomy. During surgery, marked enlargement was noted in some veins (hemiazygos and 5th intercostal veins) which apparently had been constricted by the mediastinal tumor. Surgical and radiological findings suggested a relationship between the constricted venous return due to the tumor and the patient's spinal subarachnoid hemorrhage.- - - - - - - - - - ranking = 1keywords = blood vessel, vessel (Clic here for more details about this article) |
6/60. Anterior abdominal wall malignant peripheral nerve sheath tumor in an infant.Malignant peripheral nerve sheath tumors (MPNST), also known as malignant schwannomas, are highly malignant lesions that tend to arise in the head and neck region or on the extremities, and only rarely in the retroperitoneum. These tumors are not common in children. Almost 50% of cases are associated with neurofibromatosis. When these neoplasms arise in the retroperitoneum, they usually are difficult to diagnose and to treat. Although various radiologic imaging methods are helpful for identifying some features of the mass, definitive diagnosis requires histologic examination and immunohistochemical staining. After treatment, the tumor recurs in 25% of patients. Five-year survival rates as high as 80% have been reported. Total excision, lack of invasion of surrounding tissues and vessels, and absence of neurofibromatosis, are features associated with better outcome. The authors present the case of a 1-month-old boy who had malignant schwannoma diagnosed in a unique location over the peritoneum of the anterior abdomen. The location and rapid growth of the tumor permitted early identification and total excision. J Pediatr Surg 36:1866-1868.- - - - - - - - - - ranking = 0.19991888672154keywords = vessel (Clic here for more details about this article) |
7/60. Intramedullary ancient schwannoma of the cervical spinal cord: case report and review of literature.We report a rare case of intramedullary ancient schwannoma of cervical spinal cord in a 68 year old patient. About 49 cases of intramedullary schwannomas and neurofibromas have been reported in the literature but to our knowledge there is no report of the 'ancient' variety of intramedullary schwannoma. The cell of origin of these tumours is the schwann cell, which normally does not exist in the parenchyma of the central nervous system. Many theories have been advanced to explain this paradox. According to one theory, these tumours arise from the perivascular nerve plexus of the pial vessels. This plexus was found mostly to exist along the branches of the anterior spinal artery. In our case, the tumour was supplied by two branches of the anterior spinal artery, which may add further support to the above theory.- - - - - - - - - - ranking = 0.19991888672154keywords = vessel (Clic here for more details about this article) |
8/60. March 2002: 28-year-old woman with neck and back pain.Following a car accident a 28-year-old female, complained of a sharp pain of the anterior and posterior base of the neck on expiration and with exertion. Subsequently, she noticed a feeling of discomfort in her back when lifting her arm above her head. Imaging studies revealed a tumor mass involving the third intercostal nerve on the right side of T2. The differential diagnosis included neurofibroma and neurilemmoma. This was followed annually and five years later an increase in size warranted a transthoracic, transpleural removal en bloc of this lesion. At surgery, a 3 cm soft tissue tumor engulfed the third intercostal nerve and extended into the third intervertebral foramen where the proximal part of the nerve root was enlarged. The right third intercostal nerve was dissected and removed along with the tumor, after negative nerve stimulation. Histopathological examination showed multiple enlarged coalescent lymphoid follicles with an onion skin appearance of tight concentric layering of small, uniform mature lymphocytes at the periphery, arranged in a targetoid fashion with broad mantle zones and relatively small germinal centers. The germinal centers of variable size included hyalinized blood vessels. Lollipop follicles were seen. The interfollicular stroma showed numerous hyperplastic collagenized capillaries within an inflammatory background. However, the perinodal soft tissue was replaced by numerous inflammatory cells, primarily lymphocytes. The final diagnosis was Castleman's disease, hyaline vascular type. Castleman's disease can mimic various tumors and because Castleman's disease is a rare reactive entity, its diagnosis is generally overlooked by radiologists and clinicians. It is likely that this mass arose from one of the posterior intercostal lymph nodes, situated in the paravertebral region, however the capsule was not readily seen and the sinuses were not apparent. Almost all previous cases of Castleman's disease, hyaline vascular type were described in the anterior mediastinum. Hyaline vascular Castleman's disease usually does not invade and replace neighboring structures. This case is unique because of its location and the local invasion of adjacent structures.- - - - - - - - - - ranking = 1keywords = blood vessel, vessel (Clic here for more details about this article) |
9/60. Pituicytomas, a mis-diagnosed benign tumor of the neurohypophysis: report of three cases.Pituicytoma is a rare benign primary tumor of the neurohypophysis, occurring in the sellar and suprasellar spaces. We report here three new cases with immunohistochemical and electron microscopic study. Particular attention was paid to the expression of some cell adhesion molecules. These tumors were characterized by bundles of elongated cells strongly immunoreactive to anti-vimentin, S-100 protein, neural cell adhesion molecule and neuron-specific enolase antibodies. glial fibrillary acidic protein (GFAP) was not recorded. It expressed the very late antigen alpha2 (VLAalpha2), but not VLAalpha5, and lacked epithelial markers expression (epithelial membrane antigen, E-cadherin), and specific neuronal markers (synaptophysin, chromogranin, neurofilament). Staining for pituitary hormones was negative. At the ultrastructural level, tumor/blood vessel basal lamina and cytoplasmic intermediate filaments were observed but desmosome or pericellular basal lamina were lacking. In one case few secretory granules were recorded. Differential diagnoses include granular cell tumors, pilocytic astrocytomas and spindle cell tumors such as solitary fibrous tumors, fibroblastic meningiomas and schwannomas. However, the unique pattern of antigenic expression and ultrastructural features of pituicytomas distinguish this rare tumor. As a subpopulation of pituicytes (which are distinctive glial cells of the neurophypophysis), some pituicytomas do not expressed GFAP. This suggests that pituicytomas presumably arise from pituicytes at various stages of their differentiation.- - - - - - - - - - ranking = 1keywords = blood vessel, vessel (Clic here for more details about this article) |
10/60. Retroorbital hemangiopericytoma and cavernous sinus schwannoma--case report.An 18-year-old male presented with severe proptosis and blindness in the right eye. neuroimaging revealed a large and hypervascular tumor in the right retrobulbar region and a large tumor in the left cavernous sinus. angiography showed the right tumor was extensively vascular, fed by a hypertrophic ophthalmic artery, and the left tumor was moderately vascular, fed by a large middle meningeal artery. Following embolization of the feeder vessels, the right retrobulbar hemangiopericytoma and the left cavernous sinus schwannoma were uneventfully and successfully resected. Such combinations of different pathological lesions present unusual therapeutic challenges.- - - - - - - - - - ranking = 0.19991888672154keywords = vessel (Clic here for more details about this article) |
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