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Query: UMLS:C0027651 (tumor)
 685,946 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Angiosarcoma of bone is a rare, high-grade sarcoma of vascular origin. This article describes an epithelioid angiosarcoma in the humerus of a 48-year-old man. A multilocular osteolytic lesion with undefined margins and destroyed cortical and medullary bone, associated with a large soft tissue mass was demonstrated radiologically in the proximal metaphysis of the right humerus. The tumor, resected by amputation, was composed mostly of proliferating malignant cells with an epithelioid morphology. It had a predominantly sheet-like growth pattern, and an occasional pseudoglandular or alveolar arrangement, mimicking an adenocarcinoma. The dilated anastomotic vascular spaces lined by epithelioid endothelial cells and the intracytoplasmic lumina/vacuoles that sometimes contained erythrocytes suggested focal endothelial differentiation. On immunohistochemical investigation, many neoplastic cells expressed cytokeratin and endothelial markers: factor-VIII related antigen, CD31, and UEA-I. The ultrastructure of the tumor was consistent with that of an angiosarcoma. Our patient died of disease shortly after the diagnosis, implying an aggressive clinical course. Awareness of the existence of skeletal epithelioid angiosarcoma, combined with the identification of intracytoplasmic lumina, or at least small vasoformative foci, and immunohistochemical positivity for endothelial markers provide the best guide for distinguishing this tumor from metastatic carcinomas.
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PMID:Epithelioid angiosarcoma of bone. 926 37

Thirty-two cases of so-called sclerosing hemangioma of the lung observed by light microscopy were further studied by electron microscopy and/or immunohistochemistry. Three histologic patterns were seen: hemangioma-like, papillary, and solid. The only significant component representing the nature of the lesion is characteristic round cells within the stroma in all these patterns, whereas the surface cells lining the papillary projections or cystic spaces are normal or are hyperplastic bronchioloalveolar cells with a few neuroendocrine cells. Immunohistochemical findings showed that the "stromal cells" (tumor cells) were positive for neuroendocrine markers, namely, chromogranin A (19 of 22 cases), neuron-specific enolase (24 of 24), synaptophysin (six of 10), adrenocorticotropic hormone (14 of 15), growth hormone (14 of 15), calcitonin (11 of 15), and gastrin (11 of 14). Besides, some tumor cells were positive for epithelial membrane antigen (four of four), carcinoembryonic antigen (one of four), and vimentin (one of one). All tumor cells were negative for polyclonal antikeratin antibody (25 cases), AE1 (one case), and AE3 (one case). However, in contrast to the "stromal cells," the surface cells of the cystic spaces stained positively for keratin (25 of 25 cases), AE1 (one of one), AE3 (one of one), epithelial membrance antigen (four of four), and carcinoembryonic antigen (four of four); only a few of them expressed neruoendocrine markers. Both surface and tumor cells were negative for factor VIII-related antigen (25 cases), CD31 (one case), and alpha1-antitrypsin (25 cases). Ten cases further studied by electron microscopy and six examined by ultrastructural morphometry showed that the surface cells were mainly type 2 pneumocytes containing many lamellar bodies in the cytoplasm. Lying among them, neuroendocrine cells were occasionally seen. The stromal tumor cells had no lamellar body, but dense core granules (neurosecretory granules) and microtubules. In six cases, 92.3% (345 of 374) of tumor cells contained neurosecretory granules, which were pleomorphic and 73 to 1056 nm in diameter (mean, 302 nm). Two to 193 (mean, 12) neurosecretory granules were found in each tumor cell. Both immunohistochemical findings and ultrastructural evidence indicate that so-called sclerosing hemangioma of the lung is a benign lesion composed of neoplastic neuroendocrine cells with areas of sclerosis. A suggested name for this tumor is benign neuroendocrine tumor of the lung. The differentiation between this tumor and papillary adenoma, bronchioloalveolar carcinoma, or carcinoid tumor of the lung is discussed.
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PMID:Neuroendocrine differentiation in 32 cases of so-called sclerosing hemangioma of the lung: identified by immunohistochemical and ultrastructural study. 998 55

Polymorphous hemangioendothelioma (PH) is a rare vascular neoplasm occurring in lymph nodes. It has been considered a borderline malignant tumor, mainly because of a local recurrence in one of the three cases described to date. This report adds two additional cases, one in which the tumor was extranodal. An extensive immunohistochemical study and thorough literature review were undertaken. The patients, a 55-year-old man and a 28-year-old man, both asymptomatic, presented with tumors involving a left pulmonary hilar lymph node (3 cm) and the soft tissues of the left paravertebral region (4 cm), respectively. The tumors were composed of an admixture of solid, primitive vascular and ectatic angiomatous components, with both elements formed by uniform, polygonal cells. In one case, the cells marked for CD31 and factor VIII, and the other case was positive for CD34. Neither case marked for epithelial membrane antigen and keratin. One tumor partially replaced a lymph node, and no nodal tissue was identified in the other. Of the three previously reported cases of nodal PH, one had recurring and metastatic behavior. PH is a rare, malignant vascular neoplasm that most frequently involves lymph nodes, but it can also affect extranodal locations.
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PMID:Polymorphous hemangioendothelioma: a report of two cases, one affecting extranodal soft tissues, and review of the literature. 929 85

Kaposiform hemangioendothelioma (KHE) is a rare vascular neoplasm that previously has been described only in children. We report three cases occurring in adults. The patients, two men and one woman, were aged 64, 55, and 48 years, respectively. Lesions arose on the chest wall, the lateral aspect of the neck, and in the groin and buttock, and each was situated in superficial soft tissue. Tumor size ranged from 0.9 to 7 cm. Histologically, in all cases a lobular or nodular growth pattern of densely packed spindle-shaped tumor cells closely associated with small slitlike and sievelike blood vessels was seen. Within one lesion, small nodules of plumper, epithelioid tumor cells were identified. Well-formed capillaries frequently containing fibrin thrombi were observed mainly in the periphery of tumor nodules. Areas of hemorrhage and hemosiderin deposits were observed in two cases. Associated lymphangiomatosis composed of diffusely infiltrating lymphatic spaces of the dermis and subcutis was present in one case. Nuclear atypia was minimal in all cases, and mitotic figures were rare in two cases; in one case up to 6 mitoses in 10 high-power fields were noted focally. Immunohistochemically, well-formed capillaries stained positively for all the vascular markers used; however, endothelial cells lining the small slitlike and sievelike vascular spaces did not stain for von Willebrand factor. At least focally, actin-positive pericytes were seen. Neoplastic spindled cells stained only focally for CD34 and CD31. Two lesions were excised with clear margins; in one case only repeated biopsies were done. Follow-up information between 14 and 28 months revealed no sign of recurrence or metastasis. In adults, the differential diagnosis of KHE comprises especially Kaposi's sarcoma and spindle cell hemangioendothelioma; further differential diagnoses include tufted hemangioma and cellular capillary hemangioma, which occur rarely in adults.
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PMID:Kaposiform hemangioendothelioma in adults. Clinicopathologic and immunohistochemical analysis of three cases. 932 99

Subsets of dendritic cells, fibroblasts which express the human progenitor cell antigen CD34 or histiocytes which express coagulation factor XIIIa (FXIIIa), are present in fat and in collagenous connective tissue. As components of the microvascular unit, these fibrohistiocytic cell subsets may interact during stromal remodeling, repair, and neoplasia. We studied white fat and subcutaneous fatty tumors to determine if CD34 and/or FXIIIa+ "fibrohistiocytic" dendritic cell subsets are involved in their morphogenesis. Three lipomas (L), 1 intramuscular lipoma (IL), 1 myxoid lipoma (ML), 2 pleomorphic lipomas (PL), 2 spindle cell lipomas (SCL), 8 angiolipomas (AN) in 4 patients, 1 atypical lipoma/well-differentiated liposarcoma (AL), 1 de novo dedifferentiated liposarcoma (DL), and 1 recurring atypical myxoid signet ring lipomatous tumor were examined for CD34, FXIIIa and in some cases for CD31, desmin, Ki 67, or S-100. Normal fat has scattered CD34+ dendritic cells and small FXIIIa+ dendritic histiocytes among variably S-100+ adipocytes. The CD34 and FXIIIa+ dendritic cells are more numerous near vessels and within fibrovascular septae. In L and IL, CD34 and FXIIIa+ dendritic cells are activated and some adipocytes express CD34. Mesenchymal areas of SCL, PL, ML, and AL and DL are composed of CD34+ dendritic cells with CD34+ but FXIIIa-negative floret cells in PL or atypical cells in AL and DL. FXIIIa+ dendritic cells are numerous in these lesions, comprising 30-40% of cells in SCL and PL, and 50% in ML, AL, and DL. AN have focal CD34+ interstitial cells and plump FXIIIa+ cells that in one case resembled multivacuolated lipoblasts. The myxoid signet ring lipomatous tumor was CD34 negative with few FXIIIa+ cells. We conclude that subsets of CD34+ and FXIIIa+ dendritic microvascular cells are present in normal fat and proliferate together in various types of lipomas and in at least some dedifferentiated liposarcomas.
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PMID:Fibrohistiocytic differentiation in subcutaneous fatty tumors. Study of spindle cell, pleomorphic, myxoid, and atypical lipoma and dedifferentiated liposarcoma cases composed in part of CD34+ fibroblasts and FXIIIa+ histiocytes. 933 94

Recently, angiogenic properties have been shown in preinvasive cervical lesions. Our goal was to determine the angiogenesis in cervical intraepithelial neoplasia (CIN) and the relationship between microvessel counts, histopathological parameters, and clinical outcome in invasive cervical carcinoma. One hundred thirty-eight cervical specimens were evaluated; among these 20 were designated normal epithelium, 20 low-grade CIN, 40 high-grade CIN, and 58 invasive carcinoma. Histological sections immunostained for CD31 were quantitatively evaluated for microvessel density. The tumor proliferation rate was determined by the Ki-67 Labeling Index. Comparison of microvessel counts from normal epithelium with those from CIN and invasive carcinoma showed significant increases in precancerous lesions and invasive cancer (P < 0.0001). Microvessel density was found to be associated with the overall survival in women with invasive carcinoma (P < 0.01). There was a significant correlation of microvessel density (P < 0.05) with relapse-free survival in patients with regional lymph node metastasis. A Cox stepwise regression analysis revealed microvessel density, together with depth of invasion, regional lymph node status, and vascular invasion, to be a strong independent prognostic indicator for overall survival in patients with clinical stage IB cervical carcinoma.
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PMID:Angiogenesis in cervical neoplasia: microvessel quantitation in precancerous lesions and invasive carcinomas with clinicopathological correlations. 934 52

In this report we describe a metastatic monkey hepatocellular carcinoma (HCC) model in which intravascular metastatic development is clearly evident. The tumor-bearing livers contained intravenous tumor thrombi at different stages of progression within the small branches of the portal vein. These ranged from mural tumor thrombi lined with CD31-positive endothelial cells to tumor thrombi that had completely occluded the vascular lumen. Intravenous tumor expansion was frequently accompanied by the appearance of CD31-positive microvessels within the tumor thrombi and fibrous perivascular thickening, giving rise to isolated tumor nodules within the portal areas. Intravascular expansion of disseminating HCC was also evident within small branches of the pulmonary arteries in the lungs. These findings indicate that metastases of HCC can become established while still at an intravascular stage, suggesting that the direct interaction between tumor cells and parenchymal cells predicted from experimental rodent metastasis models is not a prerequisite for the metastatic development of these tumors.
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PMID:Morphological study of vascular dissemination in a metastatic hepatocellular carcinoma model in the monkey. 936 64

Kaposi's sarcoma-associated herpesvirus (KSHV or HHV8) sequences are present in primary effusion lymphomas (PEL). KSHV+ cell lines have been established from such lymphomas. Here we report the first description of the establishment of a KSHV+, EBV- cell line (BCP-1) from the peripheral blood of a patient with PEL. Using this cell line and a KSHV+, EBV+ PEL cell line (HBL-6) previously established from ascitic fluid, we investigated whether in nonobese diabetic/severe combined immunodeficiency disease (Nod/SCID) mice tumors representing PEL can be established. When injected intravenously (IV) into Nod/SCID mice, BCP-1 and HBL-6 infiltrated organs, with only occasional macroscopic tumor formation. Intraperitoneal injections (ip) led to the development of ascites and diffuse infiltration of organs, without obviously solid lymphoma formation, resembling the diffuse nature of human PEL. To investigate a possible mechanism for the peculiar phenotype of PEL, we examine the presence of adhesion molecules and homing markers on PEL cells before and after growing in mice. Both BCP-1 and HBL-6 cells lack expression of important cytoadhesion molecules including CD11a and CD18 (LFA1 alpha and beta chains), CD29, CD31, CD44, CD54 (ICAM-1), and CD62L and E (L and E selectins).
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PMID:Establishing a KSHV+ cell line (BCP-1) from peripheral blood and characterizing its growth in Nod/SCID mice. 947 33

Microenvironmental conditions within solid tumors can have marked effects on the growth of the tumors and their response to therapies. The disorganized growth of tumors and their attendant vascular systems tends to result in areas of the tumors that are deficient in oxygen (hypoxic). Cells within these hypoxic areas are more resistant to conventional therapies such as radiation and chemotherapy. Here, we examine the hypoxic state of EMT6 mouse mammary tumors and the location of host cells within the different areas of the tumors to determine whether such microenvironmental conditions might also affect their ability to be recognized by the immune system. Hypoxia within tumors was quantified by flow cytometry and visualized by immunohistochemistry using a monoclonal antibody (ELK3-51) against cellular adducts of 2-(2-nitro-1H-imidazol-1-yl)-N-(2,2,3,3,3-pentafluoropropyl)acetam ide (EF5), a nitroimidazole compound that binds selectively to hypoxic cells. Thy-1+ cells, quantified using a monoclonal antibody, were found only in the well-oxygenated areas. The location of these Thy-1+ cells was also examined in EMT6 tumors that had been transfected with the gene for interleukin-2 (IL-2) because these tumors contain greatly increased numbers of host cells. Surprisingly, we found that IL-2-transfected tumors had significantly decreased hypoxia compared to parental tumors. Furthermore, using the fluorescent dye Hoechst 33342, an in vivo marker of perfused vessels, combined with immunochemical staining of PECAM-1 (CD31) as a marker of tumor vasculature, we found increased vascularization in the IL-2-transfected tumors. Thus, expression of IL-2 at the site of tumor growth may enhance tumor immunity not only by inducing the generation of tumor-reactive CTLs but also by allowing increased infiltration of activated T cells into the tumors.
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PMID:Interleukin 2 expression by tumor cells alters both the immune response and the tumor microenvironment. 953 51

To validate the prognostic value of the determination of p53 expression, intratumoral microvessel density (IMD) (a measure of angiogenesis), and the conventional features, we studied 531 patients operated of breast cancer (271 node-positive and 260 node-negative), with a median follow-up exceeding 6 years. IMD was assessed by using the anti-CD31 antibody to identify the microvessels. p53, estrogen receptor (ER) and progesterone receptor (PgR) were determined by immunocytochemistry using the antibodies PAb1801, H-222 Sp2y and KD-68, respectively. The prognostic value of the markers was analyzed by univariate and multivariate statistical analyses. In the overall series p53 expression, IMD, nodal status, ER and PgR were statistically significant prognostic indicators for both relapse-free survival (RFS) and overall survival (OS) in the final multivariate model. Likewise, tumor size and menopausal status were significant prognostic indicators for RFS and OS, respectively. In the subgroup of node-negative patients who did not receive adjuvant therapy only p53, IMD, and tumor size were statistically significant in multivariate analysis. In the subgroup of node-positive patients treated with adjuvant chemotherapy, IMD, the number of involved nodes and PgR were statistically significant in multivariate analysis. In the subgroup of node-positive patients treated with adjuvant tamoxifen, IMD and ER (and the number of involved nodes, only for OS) were statistically significant for both RFS and OS in the final multivariate model. Different markers played a diverse prognostic role in the diverse subgroups studied. Angiogenesis was the sole marker which retained prognostic value in all the sub-groups analyzed. p53 retained significance only in the subgroup of node-negative patients, whilst ER and PgR were statistically significant in the subgroups of node-positive patients treated with adjuvant hormone therapy or chemotherapy, respectively.
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PMID:Prognostic significance of p53, angiogenesis, and other conventional features in operable breast cancer: subanalysis in node-positive and node-negative patients. 953 38


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