1/38. 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 = blood vessel, vessel (Clic here for more details about this article) |
2/38. True hemangiopericytoma of the nasal cavity.Two cases of nasal tumors with pericytic myoid differentiation are reported. The tumors occurred in a 77-year-old woman and a 60-year-old man as polypoid lesions covered by normal mucosa. Histologically, the tumors were composed of uniform short spindle or stellate cells with indistinct cell borders arranged in narrow and short fascicles. Numerous blood vessels of various sizes were common in both cases. The tumor cells of both cases stained intensely with anti-vimentin and anti-actin antibodies, but not with anti-desmin, CD34, or anti-high-molecular-weight caldesmon antibodies. Ultrastructural examination revealed well-developed actin thin filaments with dense bodies, subplasmalemmal plaques, intercellular junctions, and irregular discontinuous basement membranes. These histopathologic features suggest true pericytic differentiation of the tumors (true hemangiopericytoma), unlike soft tissue-type hemangiopericytoma. Generally, sinonasal hemangiopericytomas are subdivided into soft tissue-type hemangiopericytomas and true hemangiopericytomas identical to the cases presented here. Soft tissue-type hemangiopericytomas are frequently highly aggressive, whereas true hemangiopericytomas show localized benign behavior. Sinonasal true hemangiopericytomas should be strictly differentiated from soft tissue-type hemangiopericytomas.- - - - - - - - - - ranking = 1keywords = blood vessel, vessel (Clic here for more details about this article) |
3/38. Intraocular hemangiopericytoma. A case report.A 55-year-old man presented with a smoothly elevated solid choroidal mass with choroidal detachment in the temporal region of the left eye. Both fluorescein and indocyanine green angiography suggested a vascularized lesion such as an angioma. However, radiographic examination revealed a solid, circumscribed, dome-shaped mass. During a 3-month observation, the mass gradually enlarged and invaded the iris. The possibility of malignant melanoma could not be ruled out. Due to rapid and continued growth of the tumor, the eye was enucleated. Histopathologic examination revealed proliferation of spindle-shaped cells surrounding reticulin-positive vessels, which is characteristic of hemangiopericytoma. To our knowledge, this is only the fourth reported case of intraocular hemangiopericytoma and the first diagnosed in a male patient.- - - - - - - - - - ranking = 0.048454863094371keywords = vessel (Clic here for more details about this article) |
4/38. Juxtaglomerular cell tumor: a clinicopathologic study of four cases and review of the literature.We studied 4 new cases of juxtaglomerular cell tumor and compared their morphologic and immunohistochemicalfeatures with 2 renal hemangiopericytomas and 5 cutaneous glomus tumors. The juxtaglomerular tumors were resectedfrom 2 males and 2 females (mean age at diagnosis, 23 years). Three patients manifested with severe hypertension. Tumors ranged from 2.2 to 8.0 cm and were well circumscribed. The tumors consisted of solid sheets and nodules of variably sized tumor cells with round, oval, and spindled nuclei alternating with edematous microcystic foci. Nuclear atypia, present in all tumors, was a prominent feature in 2. Mitotic activity was not identified. All cases showed hemorrhage, numerous mast cells, and thick-walled blood vessels. Unusual features included coagulative tumor necrosis, a hemangiopericytoma-like vascular pattern, and hyalinized stroma. All tumors were immunoreactive for CD34 and actin. Ultrastructural analysis revealed the presence of rhomboid-shaped renin protogranules. patients were treated by partial or radical nephrectomy and followed up for 14 to 48 months. There were no recurrences or metastases. The characteristic clinical and morphologic features of juxtaglomerular cell tumor permit distinction from renal hemangiopericytoma and other renal tumors.- - - - - - - - - - ranking = 1keywords = blood vessel, vessel (Clic here for more details about this article) |
5/38. 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 = 0.048454863094371keywords = vessel (Clic here for more details about this article) |
6/38. 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 = 0.048454863094371keywords = vessel (Clic here for more details about this article) |
7/38. Solitary fibrous tumor of the oral mucosa--morphological and immunohistochemical profile in the differential diagnosis with hemangiopericytoma.The objective was to investigate two cases of solitary fibrous tumor (SFT) of oral mucosa, emphasizing the differential diagnosis with one case of oral hemangiopericytoma (HPC), in terms of their morphological and immunohistochemical features. solitary fibrous tumors showed cellularity and collagenization varying from area to area, focal perivascular hyalinization, scattered giant nuclei cells and abundant mast cells throughout the tumor. The hemangiopericytoma case exhibited thin-walled and dilated vessels lined with flat endothelial cells, identified by "staghorn appearance". Tumoral cells of solitary fibrous tumor exhibited immunohistochemical positivity for CD34, as well as endothelial cells. The hemangiopericytoma was positive only in endothelial cells. In solitary fibrous tumor, alpha-smooth muscle actin, h-caldesmon and laminin stained the wall vessels. In hemangiopericytoma, on the other hand, the wall vessels were positive only for laminin, which staining was also observed in perivascular tumoral cells. The morphological and immunohistochemical differences observed allowed us to infer these lesions constitute distinct entities.- - - - - - - - - - ranking = 0.14536458928311keywords = vessel (Clic here for more details about this article) |
8/38. 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 = 0.048454863094371keywords = vessel (Clic here for more details about this article) |
9/38. Vanek's tumor (inflammatory fibroid polyp). Report of 18 cases and comparison with three cases of original Vanek's series.Eighteen cases of Vanek's tumors are presented. The patients included nine men and nine women between the ages of 45 and 93 years (mean, 66.2 years). Nine cases were clinically diagnosed as polyps of the gastric antrum, five cases as polyps of the stomach (not otherwise specified), one polyp was located in the ileum and the three remaining polyps in the small intestine (not otherwise specified). The thirteen polyps with available size information measured from 0.4 to 5 cm in the greatest diameter (mean, 2.2 cm). Immunohistochemically, the affections were positive for vimentin (18/18) and CD34 (15/18). All the cases negative for CD34 also lacked concentric onion skin-like formations of the spindle cells around glands and vessels. The different immunophenotype and absence of concentric formations could be explained by the existence of two different lesions commonly designated as Vanek's tumor (inflammatory fibroid polyp) or by the hypothesis of various evolutional stages. In the differential diagnosis, it is important to distinguish namely eosinophilic gastroenteritis, gastrointestinal stromal tumor, inflammatory pseudotumor, hemangioendothelioma, and hemangiopericytoma. In contrast to gastrointestinal stromal tumors, genetically no substitution, deletion, or insertion occurred in c-kit exon 11 in all analyzed samples. Likewise, no deletion or insertion in part of c-kit exon 9 was observed.- - - - - - - - - - ranking = 0.048454863094371keywords = vessel (Clic here for more details about this article) |
10/38. hemangiopericytoma of mesentery: a case report.Mesenteric tumors are rare, most commonly encountered lesions are fibromatoses and leiomyoma. A case of hemangiopericytoma of mesentery in a 38 years old female is reported for its rarity. The classical histological findings and recticulin stain to demonstrate blood vessels & recticulin fibers, encircling individual tumor cells aids in the correct diagnosis.- - - - - - - - - - ranking = 1keywords = blood vessel, vessel (Clic here for more details about this article) |
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