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

We report three cases of epithelioid hemangioma of small tubular bones in women aged 20, 24, and 50 years. In two patients, the tumor appeared during or shortly after pregnancy. We studied clinical data, radiographs, and hematoxylin- and eosin-stained slides, and we performed immunohistochemical and flow cytometric DNA analysis. The tumor was in distal phalanges of the fingers in two patients and in metatarsal bone in one. Cortical bone destruction with infiltration of the surrounding soft tissue was seen in all of the patients. Light microscopic examination showed characteristic morphology, highlighted by epithelioid endothelial cells with different degrees of vasoformativity. Immunohistochemically, the epithelioid cells showed strong positive reaction for Factor VIII in all three patients, for CD31 in two, and for CD34 in one. Ulex europaeus antigen and keratins were negative. Laminin and collagen IV delineated innumerable predominantly abortive vascular structures, which were encircled by cells that presumably were pericytic and that were positive for smooth muscle actin. A relatively high degree of immunostaining for proliferating cell nuclear antigen and Ki67 contrasted with the low mitotic rate and low percentage of cells in S phase. Progesterone and estrogen receptors were negative. Epithelioid hemangiomas of small tubular bones are rare lesions that are characterized by early bone destruction and infiltration of soft tissues. Their association with pregnancy may be fortuitous; if any gestation-related proliferative stimulation exists, it does not seem to be mediated through steroid receptors.
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PMID:Epithelioid hemangioma of small tubular bones: a report of three cases, two of them associated with pregnancy. 887 23

Angiosarcomas rarely develop within a peripheral nerve or a peripheral nerve sheath tumor. We describe an epithelioid angiosarcoma that arose in a benign schwannoma (neurilemoma) of the right thigh in a 65-year-old man who did not have von Recklinghausen's disease. Histologically, the resected tumor was a high-grade undifferentiated sarcoma that was predominantly arranged in solid sheets or nests and composed of epithelioid cells. The endothelial origin of the tumor was suggested by Factor VIII R-ag, Ulex europaeus-I, CD34, CD31, BNH9, and vimentin immunoreactivity, along with the ultrastructural evidence of occasional Weibel-Palade bodies. In this location, epithelioid angiosarcoma should be distinguished from malignant transformation of a schwannoma with epithelioid changes. This observation stresses the importance of immunohistochemical and ultrastructural analysis in the differential diagnosis of vascular tumors with features of epithelioid sarcoma.
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PMID:Angiosarcoma arising in a solitary schwannoma (neurilemoma) of the sciatic nerve. 889 47

The L1 adhesion molecule is a member of the immunoglobulin (Ig) superfamily initially identified in the nervous system which contains six Ig-like domains. Besides the known L1-L1 homotypic interaction, L1 was recently shown to bind to very late antigen (VLA)-5 in the mouse and alpha v beta 3 in the human. The sixth Ig domain is critical for this function. We now demonstrate that human CD4+ peripheral blood T lymphocytes, monocytes and B lymphocytes, but not CD8+ T lymphocytes, express L1. When compared to the expression of CD31, another ligand for alpha v beta 3 on T lymphocytes, only a small proportion of cells were CD31+L1+ double positive. L1 was also detected on the surface of human monocytic and lymphoid tumor lines and was shown to have a molecular mass of approximately 220 kDa, similar to the molecule present on neuroblastoma cells. The function of the sixth Ig domain of human L1 as an integrin ligand was also investigated. Using an RGD-containing peptide derived from the sixth Ig domain as well as a fusion protein of the sixth Ig domain of L1 and the Fc portion of human IgG1 (6.L1-Fc), we demonstrated the binding of human MED-B1 (alpha v beta 3hi, alpha 5 beta 1lo) tumor cells and this binding was blocked by alpha v-specific mAb. In contrast, human Nalm-6 cells (alpha v beta 3lo, alpha 5 beta 1hi) did not bind to the 6.L1-Fc fusion protein. MED-B1 cells could also be stained with the 6.L1-Fc fusion protein. Our results suggest that human L1 binds predominantly to alpha v beta 3 and that its presence on leukocytes could be important for adhesion and migration.
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PMID:L1 adhesion molecule on human lymphocytes and monocytes: expression and involvement in binding to alpha v beta 3 integrin. 889 67

Tumor vascularity has been reported to be a prognostic factor in solid tumors. We studied the prognostic value of tumor vascularity in 19 primary stage I skin melanomas. Only intermediate-thickness melanomas (0.76-4.00-mm thick) were studied. They were treated surgically to provide two groups of patients. The first group of 11 patients had no evidence of metastases after a follow-up of a mean period of 72.36 months, whereas the second one developed metastases in a mean period of 46.87 months. The two groups were matched for important prognostic factors including tumor thickness, sex, and age. Vascularity was quantified by a morphometric stereological analysis on paraffin sections stained with anti CD31 monoclonal antibody. The percentage of vascular area was significantly higher in the metastasizing group than in the nonmetastasizing one. Our study suggests that increased vascularity may have a prognostic significance in intermediate-thickness melanoma.
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PMID:Tumor vascularity as a prognostic indicator in intermediate-thickness (0.76-4 mm) cutaneous melanoma. A quantitative assay. 890 93

Tissue transglutaminase (tTG) is postulated to play a role in apoptosis, cell adhesion, metastasis, and extracellular matrix (ECM) assembly. In this study, the distribution and expression of tissue transglutaminase was investigated in normal human mammary tissue and in intraductal and invasive human breast cancer by immunohistochemistry and in situ hybridization. Frozen and formalin-fixed paraffin-embedded sections of normal, intraductal, and invasive human breast carcinoma were examined with an avidin-biotin complex immunoperoxidase method for tTG antigen and by in situ hybridization to determine the cell types expressing tTG mRNA. The expression of tTG in normal and malignant mammary epithelium in culture was evaluated by quantitative immunoblot analysis. Low-level expression of tTG was found in normal tissues with the antigen located in the ECM surrounding the ducts and in the endothelium. In intraductal cancer, there was a marked increased expression of the tTG antigen, and the increased staining was found in the ECM and was also localized in a distinct pattern at the boundary between the in situ tumor cells and the normal tissue. Further immunohistochemical analysis revealed that the cells in this boundary also stained for the endothelial cell markers CD31, CD34, and von Willebrand factor. In invasive tumors, the tTG antigen was no longer localized to the normal tissue/tumor boundary but dispersed around the tumor cells. In situ hybridization studies revealed three distinct compartments of tTG synthesis: (a) tumor cells, (b) endothelial cells, and (c) stromal cells. In addition, normal and malignant epithelial cells in culture expressed variable amounts of tTG, and the expression of tTG in these epithelial cells was at least 17-fold less than endothelial cells. The up-regulation of tTG in intraductal and invasive human breast cancer and its localization to the ECM and neovasculature suggest that tTG may regulate tumor growth and metastasis.
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PMID:Tissue transglutaminase expression in human breast cancer. 894 Dec 10

Malignant endothelial neoplasms involving the serous membranes are rare, and only a few cases have been documented. We report 14 patients with epithelioid hemangioendothelioma (EHE) or epithelioid angiosarcoma (EA) diffusely involving the pleural, peritoneal, or pericardial cavities, resulting in a picture closely resembling mesothelioma. The mean age at diagnosis was 52 (range, 34-85). The patients included two women and one man with peritoneal tumors, eight men with pleural tumors, and three men with pericardial tumors. A shared histological appearance was a diffuse sheet-like and clustered pattern of tumor growth with variable degrees of vascular differentiation. A tubulopapillary growth pattern, often seen in mesothelioma, was prominent in four cases. Nine cases showed a variable number of spindle cells, some neoplastic, others reactive, focally producing a biphasic growth pattern, further suggesting mesothelioma. Initial interpretations included mesothelioma, adenocarcinoma, and, in one case with prominent spindle-cell components, leiomyosarcoma. Immunohistochemically, strong vimentin staining and negative or weak to moderate cytokeratin staining were observed in all 14 cases. The tumor cells coexpressed at least two of the four endothelial markers used in the study (CD31, CD34, von Willebrand factor, and Ulex europaeus agglutinin-I [UEA-I)]. Detection of abortive vessel formation was facilitated by staining for collagen type IV. Markers of mesothelial, epithelial, muscular, and neuronal differentiation were all negative in the subset of cases studied. As a control group, 39 mesotheliomas and more than 60 adenocarcinomas of various origins were studied using the same antibody panel. This group revealed strong keratin staining, moderate or negative vimentin staining, and no expression of any of the endothelial-lineage markers, with the exception of positive staining for UEA-I in occasional adenocarcinomas. Clinically, these endothelial tumors were highly aggressive; 12 patients presented with disseminated disease, and most died within months of the initial presentation. These findings indicate that, although uncommon, EHE/EA should be included in the differential diagnosis of serous membrane neoplasms with histological and clinical features of malignant mesothelioma. The diagnosis of an endothelial neoplasm can be suspected by the presence of abortive vessel formation and by the strong expression of vimentin, with absent or low-level expression of cytokeratin. The demonstration of immunoreactivity for two or more endothelial-associated markers is essential in confirming the diagnosis.
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PMID:Malignant vascular tumors of the serous membranes mimicking mesothelioma. A report of 14 cases. 894 35

The binding of urokinase-type plasminogen activator (u-PA) to a specific cell surface receptor (uPA-R) has been shown to enhance plasminogen activation, a process involved in extracellular matrix degradation and cell migration during angiogenesis and tumor growth. We investigated the expression of u-PA and uPA-R in renal cell carcinomas (n = 11). By immunohistochemistry using monoclonal and polyclonal anti-uPA-R antibodies, we found that tumoral capillary endothelial cells (von Willebrand factor and CD31 positive cells) overexpressed uPA-R, whereas vascular endothelial cells of the normal human kidney do not. In addition, tumor-associated macrophages (CD68-positive cells) strongly expressed uPA-R. In contrast, few tumoral cells and stromal fibroblasts expressed uPA-R. By in situ hybridization using a cDNA S35-labeled probe specific for uPA-R, we confirmed the local expression of uPA-R messenger RNA. We also detected the induction of u-PA in tumoral capillary endothelial cells and in tumor-associated macrophages. In two cases, tumoral cells themselves were also stained by anti-u-PA antibodies in focal areas. Finally tissue-type plasminogen activator (t-PA) was also overexpressed by tumoral capillary endothelial cells as compared with endothelial cells of normal human kidney vessels. These findings indicate an active invasive phenotype of endothelial cells in renal cell carcinoma and suggest a role for the plasminogen activation system in tumoral angiogenesis and invasion.
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PMID:Endothelial and macrophage upregulation of urokinase receptor expression in human renal cell carcinoma. 902 4

Thallium chloride 201Tl combined with SPECT was performed in a series of 29 patients with neuroradiological evidence of vestibular schwannoma (VS). The relative tumor uptake (U) and relative tumor concentration (C) of the radiotracer 201Tl was determined, and the cerebellum served as a reference. The relative tracer concentration and uptake were correlated to tumor volume determined by gadolinium DTPA enhanced MR, to prediagnostic duration of symptoms, to tumor vascularity expressed by the average number of intratumoral vessels using the endothelial marker CD31, and to the proliferative activity in the tumors expressed by positive staining with the monoclonal antibody MIB-1 for Ki-67. A positive 201TI enhancement was detected in 17 tumors (n = 17). Tumors U and C were statistically unrelated to tumor volume (p = 0.236 and p = 0.439). SPECT demonstrated all tumors > 0.8 cm3, but it had its limitation as a diagnostic modality of small intracanalicular tumors, when compared with gadolinium DTPA enhanced MR. Relating U and C in all tumors (n = 29) and the prospectively registered data on the prediagnostic duration of symptoms, a statistical significance was found (p = 0.012 and p = 0.015). No statistically significant correlation was observed between U and C and the proliferative activity of the tumors expressed by positive staining with the monoclonal antibody MIB-1 for Ki-67 (p = 0.063 and p = 0.086). A statistically significant correlation was noted between C and U in the operated group (n = 12) and tumor vascularity expressed by the average number of the intratumoral vessels (p = 0.003 and p = 0.014). SPECT was found to be superior to MR in determining VS growth potentials as it expresses tumor vascularity, which is essential for tumor growth. It seems that we now have an in vivo functional radiological modality capable of providing data on VS vascularity and determination of growth potential in the individual tumor. A high radioactive tracer uptake in the tumor corresponded to high tumor vascularity, indicating a high growth rate and vice versa.
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PMID:Thallium chloride 201Tl combined with single photon emission computed tomography (SPECT) in the evaluation of vestibular schwannoma growth. 903 78

Eighteen examples of an unusual malignant soft-tissue neoplasm, the morphology of which ranged from that of "atypical" epithelioid sarcoma to that of a rhabdoid tumor or undifferentiated carcinoma (with transitional forms) are described. Patients included 11 males and seven females; their median age was 35.5 years with most patients aged 20 to 40 years. Development of a mass was the main presenting symptom. Six tumors developed in the pelvis and perineal region, four in the pubic region and vulva, three in the buttocks, one in the deep soft tissues of the left hip, one on the penis, one in left forearm, one in left axilla, and one on the occiput. Tumor size ranged from 1 to 20 cm (median, 4 cm). On microscopic examination, the tumor cells invaded the subcutaneous or deep soft tissues, had prominent epithelioid or rhabdoid features, had marked cytologic atypia, and grew in a multinodular pattern in half of the cases. Areas of necrosis were often seen. A granuloma-like pattern reminiscent of that observed in classic epithelioid sarcoma was observed in only two cases. Immunohistochemically, positivity for cytokeratin, epithelial membrane antigen, and vimentin was seen in all but one of the cases. Of 16 cases, 10 and eight tumors reacted with desmin and CD34, respectively; five of 15 reacted at least focally with smooth-muscle actin, whereas three of 13 and one of 10 reacted for HMB-45 and carcinoembryonic antigen, respectively. S-100 protein and CD31 yielded negative results. Seven tumors were investigated at the ultrastructural level, four of which showed prominent intracytoplasmic intermediate filament aggregates, often accumulating into paranuclear whorls, which is in keeping with the rhabdoid phenotype. Five tumors showed features of epithelial differentiation (i.e., tonofilament-like structures or desmosomes or both), whereas one tumor displayed features of myofibroblastic differentiation. Differential diagnoses include mainly conventional epithelioid sarcoma, extrarenal malignant rhabdoid tumor, epithelioid malignant peripheral nerve sheath tumor, melanoma, rhabdomyosarcoma, and undifferentiated carcinoma. Follow-up information on 14 patients (range, 4 months to 8 years; median, 19 months) revealed local recurrence in one case and metastatic dissemination in six patients, leading to death in five. In our opinion, the above-described neoplasms represent a usually "proximal-type" of epithelioid sarcoma. In contrast to the conventional, "distal-type" epithelioid sarcoma, the proximal variant is characterized by a predominantly large-cell, epithelioid cytomorphology, marked cytologic atypia, frequent occurrence of rhabdoid features, and lack of a granuloma-like pattern in most cases. It appears to be somewhat more aggressive (or at least metastasizes earlier) than usual epithelioid sarcoma.
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PMID:"Proximal-type" epithelioid sarcoma, a distinctive aggressive neoplasm showing rhabdoid features. Clinicopathologic, immunohistochemical, and ultrastructural study of a series. 904 79

CD44 variants carrying sequences encoded by exon v6 are preferentially expressed in metastatic animal cancer cell lines. CD44v6 overexpression correlates tumor dedifferentiation and progression in some human carcinomas, but the relationship of CD44v6 overexpression with metastatic behavior of tumor observed in animal models is controversial, particularly in breast carcinomas. The discrepancies probably result from analytical bias. We investigated CD44v6 and CD44s expression in 218 frozen samples of primary breast carcinomas. Immunocytochemical procedure was performed under optimal technical conditions using commercially available 2F-10 monoclonal antibody (MAb), a microprocessor-controlled automated device (Ventana Medical Systems, Tucson, AZ), and quantitative evaluation of results by processing digitized-colored microscopic images (SAMBA, Grenoble, France). CD44v6 expression in tissue sections was shown to be independent of the patient age, tumor size, histological types and grades, and the lymph node status. CD44v6 expression was also independent of the expression of molecules endowed with poor prognostic significance detected by MAbs (anti-p53, anti-c-erb B-2 protein, MIB1) on consecutive sections. No significant relationship could be evidenced either between CD44v6 expression, and CD31 involved stromal angiogenesis and cathepsin D. Finally, CD44v6 was independent of markers of hormone dependence (estrogen and progesterone receptors, pS2) and of multidrug resistance (P-glycoprotein). Similar results were observed with anti-CD44s. We conclude that the true prognostic significance of CD44v6 overexpression still remains to be shown under rigorous technical conditions (frozen samples, well-documented MAbs, and optimal standardization of procedure using automation and quantitative analysis) providing data appropriate for further correlation with long-term patient follow-up.
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PMID:Automated and quantitative immunocytochemical assays of CD44v6 in breast carcinomas. 904 92


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