1/17. Clinicopathological features of solitary fibrous tumor of the meninges: An immunohistochemical reappraisal of cases previously diagnosed to be fibrous meningioma or hemangiopericytoma.Cases of solitary fibrous tumor (SFT) of the meninges are increasingly being reported. However, the real incidence of SFT among meningeal tumors has yet to be determined. We therefore clinicopathologically re-examined 64 meningeal tumors originally diagnosed to be either fibrous meningioma (FM group, n = 46) or hemangiopericytoma (HPC group, n = 18) while paying special attention to SFT. We thus reclassified one case from the FM group (2%) and one case from the HPC group (6%) to be SFT, both of which showed diffuse CD34-immunoreactivity and dense intercellular reticulin fibers but neither epithelial membrane antigen nor S-100 protein expression. The MIB-1 staining index of these cases were 6. 2% and 3.9%, respectively. The former recurred 15 years after the initial surgery and the patient underwent a second removal of the tumor. The patient has been alive with no evidence of recurrence for 7 years after the second surgery. The latter patient has been alive with no evidence of recurrence for 3 years postoperatively. The results confirmed that the incidence of SFT among meningeal tumors is relatively low, however, because of its clinically indolent nature, a careful histochemical examination is necessary to differentiate SFT from other neoplasms with a more aggressive nature. Our findings emphasize the need to clinically recognize this lesion as a distinct entity.- - - - - - - - - - ranking = 1keywords = antigen (Clic here for more details about this article) |
2/17. Solitary fibrous tumor arising from the falx cerebri--case report.A 50-year-old female was admitted with headache and visual disturbance. neuroimaging demonstrated a well-demarcated large tumor attached to the falx cerebri. The tumor was totally removed by surgery. Histological examination showed that the tumor consisted of spindle cells with no pattern in the collagenous background. Staghorn-like blood vessels were common. Immunohistochemical study showed the tumor cells were strongly positive for CD34 and vimentin, but negative for epithelial membrane antigen. The diagnosis was solitary fibrous tumor arising from the falx cerebri. Solitary fibrous tumor is rare within the cranial cavity, and can be distinguished from meningioma and hemangiopericytoma by the histological, ultrastructural, and immunohistochemical findings.- - - - - - - - - - ranking = 1keywords = antigen (Clic here for more details about this article) |
3/17. A case of metastatic malignant hemangiopericytoma of the ovary: recurrence after a period of 17 years from intracranial tumor.hemangiopericytoma is an uncommon vascular tumor. Primary or metastatic hemangiopericytoma of the ovary is extremely rare. A 48-year-old Japanese woman had a tumor in the neck. Simultaneously, a solid ovarian tumor was detected. She had received treatment for intracranial hemangiopericytoma 17 years previously. For the ovarian tumor, she underwent a total abdominal hysterectomy and bilateral salpingo-oophorectomy. The left ovarian tumor weighed 1510 g and its cut surface was solid without areas of hemorrhage or necrosis. It was microscopically composed of tightly packed tumor cells outside of many vascular vessels. One or two mitotic figures were counted per 10 high power fields. Immunohistochemically, vimentin was expressed but factor-VIII-related antigen, CD 31, and CD 34 were not expressed in the tumor cells. Electron microscopy showed that the tumor cells were grown outside of the endothelium-lined vascular spaces. A discontinuous external basal lamina was also observed. We present a case of metastatic malignant hemangiopericytoma of the ovary from a primary intracranial hemangiopericytoma with a long interval of 17 years.- - - - - - - - - - ranking = 1keywords = antigen (Clic here for more details about this article) |
4/17. Primary synovial sarcoma of the kidney: a case report with literature review.We describe a case of primary renal synovial sarcoma (SS) in a 48-year-old man. The patient presented with hematuria and was found to have a large tumor in his left kidney on computed tomography scan. histology revealed a highly cellular spindle cell neoplasm with minimal pleomorphism. The major differential diagnoses included leiomyosarcoma, hemangiopericytoma, and SS. The presence of focal areas with a biphasic pattern, uniformly positive immunostain for bcl-2, focally positive immunostains for epithelial membrane antigen and cytokeratin, and negative immunostains for CD-34, smooth muscle actin and S-100 established the diagnosis. This was subsequently confirmed by molecular testing for t(X;18) translocation. Since the existence of primary SS in the kidney was first suggested in 1999, to the best of our knowledge a total of 19 cases including the present case have been reported to date. Although primary renal SS is rare, these findings indicate that it should be included in the differential diagnosis of spindle cell tumors of the kidney.- - - - - - - - - - ranking = 1keywords = antigen (Clic here for more details about this article) |
5/17. myofibromatosis-like hemangiopericytoma metastasizing as differentiated vascular smooth-muscle and myosarcoma. Myopericytes as a subset of "myofibroblasts".A thyroid hemangiopericytoma that was resected in a 5-year-old boy recurred insidiously in the larynx 8 years later. Marked cicatricial mucosal inflammation prevented a definitive pathologic diagnosis of recurrence until a nodule grew to obstruct the airway 15 years after initial surgery. After excision of the nodule, a larger sarcomatous metastasis was discovered in the upper esophagus and resected, but the patient eventually succumbed to widespread disease at the age of 20 years. The original tumor contained atypical pericytes and bundles of hyalinizing smooth muscle abutting on "staghorn vessels," a pattern similar to infantile myofibromatosis. desmin immunostaining was negative in the pericytes but positive in smooth-muscle cells dispersed singly as well as in bundles. Both elements reacted strongly for vimentin and the alpha-isoform of actin (alpha-SMA) found in normal smooth muscle and pericytes. A third cell type showing dendritic processes and immunoreactivity for all three antigens was interpreted as a myopericyte. Spindled cells in multiple subsequent mucosal biopsy specimens stained retrospectively also positive for these antigens. Large bundles of vascular smooth muscle surrounded by radiating myocytes characterized the occluding laryngeal nodule. In the esophageal metastasis, which showed no histologic features typical of hemangiopericytoma, numerous mitotically active, small, vimentin , desmin , alpha-SMA cells often maintained shortened processes and tended to form nodular aggregates about capillaries. Single rows of pericytes accreted to endothelial tubes. Ultrastructurally, some cells contained myofilaments and irregular dense material or showed rare cell junctions and variable investment by a basal lamina.(ABSTRACT TRUNCATED AT 250 WORDS)- - - - - - - - - - ranking = 2keywords = antigen (Clic here for more details about this article) |
6/17. A novel case of synovial sarcoma of the kidney: impact of SS18/SSX analysis of renal hemangiopericytoma-like tumors.We report a new case of synovial sarcoma of the kidney. The patient underwent nephrectomy because of a large tumor in the right kidney. The histologic diagnosis was hemangiopericytoma. Less than 1 year after primary surgery the patient was reoperated due to massive local recurrence. histology now revealed a poorly differentiated tumor tissue with hemangiopericytoma-like features. Immunostainings showed immunoreactivity to cytokeratin, epithelial membrane antigen, and vimentin. The tumor was negative to CD34 and factor viii. The tumor cell proliferation, assessed by Ki-67, was high. RT-PCR analysis and sequence analysis demonstrated the presence of SS18/SSX2 fusion gene. review of the histologic specimens from the original tumors confirmed hemangiopericytoma-like morphology. The new diagnosis was poorly differentiated synovial sarcoma. At the time of reoperation, lung metastases were detected radiologically, reflecting a very aggressive phenotype. To our knowledge, this is the third case of poorly differentiated synovial sarcoma of the kidney. Common for all these three cases is the hemangiopericytoma-like histology and a very aggressive clinical behavior. These circumstances accentuate the impact of SS18/SSX analysis in diagnosis of renal hemangiopericytoma-like tumors.- - - - - - - - - - ranking = 1keywords = antigen (Clic here for more details about this article) |
7/17. Meningeal hemangiopericytoma with delayed multiple distant metastases.A 43-year-old housewife suffered from an occipital headache, and brain computed tomography (CT) showed an occipital meningeal tumor. She received a complete tumor excision and the tumor pathology was interpreted as atypical meningioma. Five years later, a subacute left neck pain with radiation to the left arm occurred. A tumor invading the second and third cervical vertebrae with compression on the dural sac was found. angiography revealed hypervascular tumor staining supplied from the left vertebral artery. CT-guided biopsy was performed and nests of atypical spindle cells accompanied by staghorn vascular pattern were revealed histologically. Immunohistochemical studies showed positive vimentin staining but negative reactions to epithelial membrane antigen, cytokeratin low molecular weight, cytokeratin high molecular weight, CD34 and S-100 protein. Estimation of the Ki-67 proliferative (mitotic) index by using MIB-1 monoclonal antibody was 12%. Later on, a systemic survey revealed lesions in the left lung, liver and kidney. The diagnosis was revised to hemangiopericytoma. Distant metastasis is common in this tumor. However, the delayed multiple metastases without local recurrence were relatively rare. The clinical course in this patient also supported that a high mitotic activity may correlate with a poor prognosis even if the pathology is taken from the metastatic tissue, and that long-term follow-up is mandatory. Detailed immunohistochemical staining is helpful in avoiding misdiagnosis of meningioma.- - - - - - - - - - ranking = 1keywords = antigen (Clic here for more details about this article) |
8/17. prenatal diagnosis of a giant congenital primary cerebral hemangiopericytoma.Congenital primary intracranial hemangiopericytomas are exceptionally rare tumors. We present a case of a fetus, with the prenatal sonogram at 33 weeks of gestation revealing a large cerebral tumor. Because of the enlarged head, a cesarean section was performed. The tumor was confirmed by postnatal ultrasound, magnetic resonance imaging (MRI) and biopsy. Elevated intracranial pressure and hemorrhage led to death on the 11th day. autopsy revealed a 10x9 cm large inhomogeneous tumor located centrally, mainly in the posterior fossa. histology showed a hypercellular and hypervascular tumor with extended necrosis and high mitotic rate. The tumor cells were positive for vimentin and CD34 antigens and negative for several neurological markers, desmin and CD31. The diagnosis of a congenital primary cerebral hemangiopericytoma was confirmed.- - - - - - - - - - ranking = 1keywords = antigen (Clic here for more details about this article) |
9/17. Cellular haemangioma. light and electron microscopic studies of two cases.light and electron microscopic studies were conducted on the immature vascular tumors of two infants, containing various stages of differentiation of the blood vessels and both benign haemangioendotheliomas and haemangiopericytomas. We were able to confirm the existence of two kinds of hyperplastic, immature cells i.e. endothelial cells and pericytes in the same tumor. Presence of crystalloid inclusions in the endothelial cells and absence of the weibel-palade bodies, as well as a deficiency in factor viii-related antigen and no tissue fibrinolytic activity, suggested that the endothelial cells in these lesions were immature. Electron microscopic studies appear more decisive in the diagnosis of heterogenous cellular vascular tumors than light microscopy and if available should be used to aid in the final diagnosis. The authors propose that the term cellular haemangioma would be more appropriate in describing this vascular entity.- - - - - - - - - - ranking = 1keywords = antigen (Clic here for more details about this article) |
10/17. meningioma-like tumor of the skin. An ultrastructural and immunohistochemical study.Three unusual cutaneous tumors are described along with ultrastructural and immunohistochemical studies. All lesions were asymptomatic red-brown papulonodules. light microscopic examination revealed a whorled configuration of spindle-shaped cells, some concentrically arranged around blood vessels. Immunohistochemical panels exhibited positive staining only with antibody to vimentin and negative staining with antibodies against S-100 protein, muscle markers, cytokeratin, epithelial membrane antigen, Leu 7, type IV collagen, and factor xiiia, ruling out obvious nevomelanocytic, nerve sheath, meningothelial, smooth muscle, and perithelial differentiation. Electron microscopic examination demonstrated cells producing poorly formed collagen fibrils, sparse collagen fibers, and possessing occasional ill-defined intercellular junctions between their elongated cell processes. This rare tumor is considered to be either an immature fibrohistiocytic or possibly a nerve sheath neoplasm with striking similarities to so-called canine hemangiopericytoma. Because the prominent whorled pattern was reminiscent of meningioma, the lesion was referred to as meningioma-like tumor of the skin.- - - - - - - - - - ranking = 1keywords = antigen (Clic here for more details about this article) |
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