Search results for "sarcoma"

Value of nude mice xenografts in the expression of cell heterogeneity of human sarcomas of bone and soft tissue.

1988

Summary Nude mice xenotransplants have been performed on human primary sarcomas of bone and soft tissues in order to delve into the cell heterogeneity of these neoplasms. Particular emphasis has been given to the group of small round blue cell sarcomas (Ewing's sarcomas and peripheral neuroectodermal tumors). Out of 31 xenotransplanted sarcomas, 16 cases have grown positively, and many of them continue to be transferred into nude mice on a regular time basis, being presently considered as fully established nude lines. Here we report the results of such a system, which has been followed with optical, electron microscopical, immunohistochemical and cytogenetic techniques. Osteosarcomas make u…

Gliofibromas (including malignant forms), and gliosarcomas: a comparative study and review of the literature

1993

The presence of connective tissue elements in gliomas necessitates in every case a thorough analysis of the character and derivation of such elements to allow the formulation of an appropriate diagnosis. Four cases are presented in this paper. In cases 1 and 2 (anaplastic astrocytomas in two children, 9 and 4 years old, respectively) all the neoplastic elements were astrocytes and their ability to produce or indirectly promote the production of reticulin and collagen fibers accounted for the presence of such elements in close association with the tumor cells. The term "gliofibroma" has been coined for such tumors, but "desmoplastic astrocytoma", (low grade or anaplastic) or in highly malign…

A tissue microarray study of osteosarcoma: histopathologic and immunohistochemical validation of xenotransplanted tumors as preclinical models.

2010

Osteosarcomas (OS) are aggressive neoplasms with a wide range of morphologic patterns.OS cases (primary and xenotransplanted) with paraffin blocks available were collected and included in tissue microarrays (TMAs). A morphologic evaluation including the different passages in mice was carried out according to the new WHO criteria. In addition, TMAs were analyzed with a wide panel of immunohistochemical (IHC) markers (osteonectin, osteocalcin,cytokeratin, S100, Sox-9, Ki-67, Bcl-2, p53, p16, survivin, CD99, and caveolin-1).A total of 61 cases were collected. The distribution of the cases according to the histopathologic pattern was: 38 osteogenic OS, 8 primary chondrogenic OS, 2 primary telan…

Hypoxyradiotherapy: lack of experimental evidence for a preferential radioprotective effect on normal versus tumor tissue as shown by direct oxygenat…

1998

Abstract Aim : In order to investigate possible pathophysiological mechanisms underlying the postulated preferential protective effect of hypoxia on normal tissue during radiotherapy, the impact of acute respiratory hypoxia (8.2% O 2 + 91.8% N 2 ) on tissue oxygenation was assessed. Methods : Tumor and normal tissue oxygenation was directly determined using O 2 -sensitive electrodes in two experimental rat tumors (DS and Yoshida sarcomas) and in the normal subcutis of the hind foot dorsum. Results : During respiratory hypoxia, arterial blood O 2 tension (pO 2 ), oxyhemoglobin saturation and mean arterial blood pressure decreased. Changes in the arterial blood gas status were accompanied by …

Slow-growing angiomatous lesions on the limbs.

2014

Mesenchymal chondrosarcoma of maxilla : a rare case report

2010

Mesenchymal chondrosarcoma (MC) is a rare variant of chondrosarcoma (CS) that accounts for upto 3-9% of all CS and has high predilection for the head and neck region. It is usually seen in younger age group compared to conventional CS and maxillary anterior alveolus is the most common site. The tumor is most unusual as it has been described as a particularly aggressive neoplasm with a high tendency for late recurrence and delayed metastasis. It is a biphasic tumor with areas comprising of spindle cell mesenchyme interspread with areas of chondroid differentiation. A 75 year old male presented to us as a painless mass in maxilla. Contrast enhanced computed tomography (CECT) revealed a lytic …

Biphasic dermatofibrosarcoma protuberans with a labyrinthine plexiform high‐grade fibrosarcomatous transformation

2013

Several variants of dermatofibrosarcoma protuberans, a low-grade superficial sarcoma, are well recognized. The most prognostically important is the fibrosarcomatous variant. We report a case of biphasic dermatofibrosarcoma protuberans in which the high-grade component exhibited a previously undescribed plexiform pattern. A clinicopathological study complemented with immunohistochemical, ultrastructural, reverse transcription polymerase chain reaction and fluorescence in situ hybridization analyses of this unique case. Histopathologically, a conventional low-grade dermatofibrosarcoma protuberans was admixed with intratumoral high-grade areas showing a striking labyrinthine plexiform pattern …

Incidence of childhood cancer of the head and neck in Germany.

2007

Background: Only very limited data are available in the literature on the incidence of childhood cancer of the head and neck worldwide. Methods: Based on data obtained from the national German Childhood Cancer Registry, a total of 370 malignancies of the head and neck in children under the age of 15 (199 boys and 171 girls), which were reported to this institution between 1994 and 2003, were analysed in this study. Results: The overall incidence of malignancies of specific sites of the head and neck in Germany is 4.48 per 100000 children. The most frequently observed entities, representing primary tumours, are soft tissue sarcomas (0.39/100000), lymphomas (0.09/100000) and thyroid carcinoma…

Childhood cancer and residential radon exposure - results of a population-based case-control study in Lower Saxony (Germany)

1999

A population-based case-control study on risk factors for childhood malignancies was used to investigate a previously reported association between elevated indoor radon concentrations and childhood cancer, with special regard to leukaemia. The patients were all children suffering from leukaemia and common solid tumours (nephroblastoma, neuroblastoma, rhabdomyosarcoma, central nervous system (CNS) tumours) diagnosed between July 1988 and June 1993 in Lower Saxony (Germany) and aged less than 15 years. Two population-based control groups were matched by age and gender to the leukaemia patients. Long-term (1 year) radon measurements were performed in those homes where the children had been liv…

Splenic blood flow and intrasplenic flow distribution in rats

1977

In 75 rats, anesthetized with pentobarbital and breathing spontaneously, regional splenic blood flow (rSBF) was measured by means of the85Kr(β)-clearance technique after an intraaortic slug injection of the dissolved indicator. In the normal and undisturbed spleen in situ rSBF is linearly related to the mean arterial blood pressure (MABP) within the range of 30–140 mm Hg. Mean rSBF is 0.71 ml/g/min, the mean arterial blood pressure being 105 mm Hg. In normal rats rSBF decreases significantly with increasing body weight or age. After total obstruction of the open circulation by application of rigid spherocytes, mean rSBF is reduced to 0.26 ml/g/min and is independent of the mean arterial blo…