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

This report describes a case of a malignant vascular tumor of the spleen with the morphologic, immunologic, and ultrastructural features observed in splenic sinus-lining cells (littoral cells). Histological examination showed a well-differentiated neoplasm forming ectatic blood channels with intraluminal papillary fronds. Tumor cells displayed malignant nuclear features and hemophagocytosis. Solid neoplastic areas with mitotic figures were present. Ultrastructurally, the tumor cells showed the concomitant presence of lysosomes and Weibel-Palade bodies. Immunohistochemically, the tumor cells were positive for both endothelial (Factor VIII-AG, CD34) and histiocytic markers (cathepsin D, lysozyme, alpha-1-antichimotrypsin). Our results indicate that angiosarcoma may originate from all the vascular compartments of the spleen, including red-pulp sinuses, and may have morphologic and immunophenotypic similarities to littoral cell angioma, a recently described benign vascular tumor of the spleen.
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PMID:Littoral cell angiosarcoma of the spleen. Case report with immunohistochemical and ultrastructural analysis. 757 79

A series of seven cases of a previously unrecognized potentially recurrent tumor occurring in the orbit of adult patients is reported. This lesion shows histologic appearances intermediate between, but distinct from, solitary fibrous tumor and giant cell fibroblastoma of soft tissue. Morphologically it is characterised by a richly vascularized, patternless spindle-cell proliferation containing pseudovascular spaces. Multinucleate giant cells (often of floret type) and cells with large, rounded nuclei are present both in the cellular areas and also lining the pseudovascular spaces. The stroma is variably collagenized or sometimes myxoid. Immunohistochemically, the tumor cells exhibit positivity for vimentin and CD34. Follow-up in five cases (median duration 24 months) revealed local recurrence in one patient and persistent tumor in another. The clinical and morphologic features enable distinction of this lesion from both solitary fibrous tumor and giant cell fibroblastoma, and we suggest the designation "giant cell angiofibroma of the orbit".
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PMID:Giant cell angiofibroma. A distinctive orbital tumor in adults. 757 91

Pulmonary artery angiosarcoma is a rare entity. We report a case of an epithelioid angiosarcoma developing from the right pulmonary artery with pulmonary parenchymal invasion. The patient was a 69-year-old man who presented with massive hemoptysis and shortness of breath. Right middle and lower lobectomies were performed because of uncontrollable bleeding. An angiosarcoma was observed developing from the right pulmonary artery with contiguous spread down smaller artery branches with invasion of the pulmonary parenchyma. Although typical angiosarcomatous areas were observed, the neoplasm was dominated by cells with an epithelioid morphology. Immunohistochemically, the majority of cells stained for endothelial markers factor VIII-related antigen and CD34, but in addition, the cells with an epithelioid morphology stained intensely for cytokeratin. Knowledge of cytokeratin positivity in epithelioid vascular neoplasms is critical to avoid a misdiagnosis of carcinoma, particularly at sites where carcinoma is a much more likely diagnosis.
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PMID:Epithelioid angiosarcoma of the pulmonary artery. 759 Jul 4

We describe a cutaneous angiomyxoma on the head of a 38-year-old man without evidence of Carney's complex. Complete excision of the tumor appeared to be curative. Histologic examination revealed fibroblast-like cells embedded in a well-demarcated, lobulate, mucinous, and vascularized stroma with a delicate reticulin network. Immunohistologically, the stromal cells were consistently positive for vimentin and focally positive for smooth muscle A-actin but were negative for desmin, KP1, MAC387, factor XIIIa, CD34, Leu-7, and S-100. Cutaneous angiomyxoma appears to represent a myofibroblastic neoplasm that should be distinguished from cutaneous focal mucinosis.
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PMID:Cutaneous angiomyxoma: a benign neoplasm distinct from cutaneous focal mucinosis. 761 84

High-dose therapy with stem cell rescue is increasingly being used as a salvage or consolidation therapy for patients with poor-risk malignant disease. The availability of peripheral blood progenitor cells (PBPC) has opened new therapeutic perspectives to alleviate the severe toxicity related to prolonged myelo-suppression. The preferred method of collection is still a matter of much debate. PBPC can be collected in steady state and after chemotherapeutic conditioning, growth factor priming, or both. Usually a heterogeneous population containing both committed progenitors and pluripotent stem cells can be harvested. Studies comparing engraftment after mobilized PBPC with recovery after autologous bone marrow transplantation confirm the beneficial effect on neutrophil and platelet engraftment. The accelerated hematological recovery can be associated with a number of clinical benefits including a reduction of platelet transfusions and shorter hospital stay. Only a few randomized studies are currently available on the long-term outcome after PBPC transplantation. Recent findings on tumor cell mobilization stimulated the development of techniques for tumor cell reduction, based on negative selection ("purging") of tumor cells or positive selection of CD34-positive progenitor cells. Positive CD34 selection is also imperative for successful ex vivo expansion of progenitor cells and gene transfer experiments. The value of PBPC in the field of allogeneic transplantation is currently being examined.
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PMID:An update on peripheral blood progenitor cell transplantation. 763 15

The accurate immunohistochemical diagnosis of epithelioid angiosarcoma--as distinct from carcinomas and other epithelioid neoplasms--is hindered by the lack of endothelial-selective reagents that are both sensitive and specific. To evaluate the potential utility of an "epithelial-specific" and an "endothelial-selective" monoclonal antibody in this differential diagnosis, B72.3 [anti-TAG 72 (tumor-associated glycoprotein-72)] and My 10 [anti-CD34 (the hematopoietic progenitor cell antigen)] were applied to 14 examples of angiosarcoma (seven with an epithelioid phenotype), nine epithelioid hemangioendotheliomas, and eight capillary hemangiomas, together with antibodies to factor VIII-related antigen (F8rag) and cytokeratin (CK), and the lectin Ulex europaeus I (UEA). The results of these analyses were compared with stains fro B72.3, CD34, and Ck in a variety of other epithelioid soft tissue neoplasms, including four epithelioid sarcomas, three epithelioid malignant peripheral nerve sheath tumors, three alveolar soft part sarcomas, four clear cell sarcomas (malignant melanomas of soft parts), five malignant fibrous histiocytomas, and seven epithelioid leiomyosarcomas. The endothelial phenotype of each vascular tumor was supported by staining for either F8rag or UEA in all examples. Only angiosarcomas were reactive with B72.3, including five of seven epithelioid variants. None was positive for cytokeratin. Four epithelioid angiosarcomas were also reactive for CD34, but so were the majority of epithelioid leiomyosarcomas and at least one example each of all other epithelioid soft tissue tumors, except alveolar soft part sarcoma. In contrast, none of the latter tumor types was reactive with B72.3. These data indicate that anti-CD34 is not specific for endothelial tumors, whereas B72.3 reactivity is selective for epithelioid angiosarcomas. Despite published reports to the contrary, no tumor in this series was reactive for cytokeratin. An immunohistochemical panel that includes antibodies to both cytokeratin and B72.3, in addition to other lineage-selective mesenchymal markers, is useful in the diagnostic recognition of epithelioid soft tissue neoplasms.
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PMID:B72.3 and CD34 immunoreactivity in malignant epithelioid soft tissue tumors. Adjuncts in the recognition of endothelial neoplasms. 767 85

The human hematopoietic progenitor cell antigen is known as CD34. This antigen is present on normal bone marrow progenitor cells and vascular endothelial cells. We used the monoclonal antibody anti-CD34 and immunoperoxidase staining techniques to evaluate the expression of CD34 in benign and malignant vascular and spindle cell tumors. All of the 42 vascular lesions, except two of three lesions of intravascular papillary endothelial hyperplasia, demonstrated diffuse membraneous staining of moderate to strong intensity of their endothelial cells. Also, normal placentas (five) showed similar staining. All neurofibromas (12), three of five neuromas, and one of four neurilemmomas revealed moderate to strong, diffuse, membraneous staining. Five of eight piloleiomyomas, two of seven angioleiomyomas, and one of five uterine leiomyomas showed focal to diffuse, and weak to moderate, membraneous staining in the smooth muscle component. Six dermatofibrosarcoma protuberans were studied: generalized, strongly positive membraneous staining was present in four. All specimens showed staining of the normal endothelial cells and the cells surrounding the hair follicles (bulge area), sebaceous glands, and eccrine glands. No staining was demonstrated in any of the following fibrohistiocytic tumors: atypical fibroxanthomas (two), fibrous dermatofibromas (23), giant cell tumor of tendon sheath (one), and hemosiderotic dermatofibromas (18). Melanocytic tumors [Spitz nevi (three) and spindle cell superficial spreading malignant melanoma (one)], Merkel cell carcinomas (six), and spindle cell squamous cell carcinomas (two) did not stain with anti-CD34. Glomus tumors (two) and a hemangiopericytoma were also negative except for their vascular channels.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Expression of the human hematopoietic progenitor cell antigen CD34 in vascular and spindle cell tumors. 751 50

Nerve growth factor, S-100 protein, CD44, and CD34 have unique expressions in or surrounding eccrine coil but are not found in eccrine duct or apocrine gland. We studied 15 cases of cutaneous cylindroma to see if these antigens are found in this neoplasm. All were found in cylindroma to varying degrees. These results link the histogenesis of cylindroma to the eccrine coil. A unique feature of cylindroma is the large number of prominent dendritic cells most likely representing Langerhans cells that permeate the tumor aggregates.
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PMID:Cylindroma expresses immunohistochemical markers linking it to eccrine coil. 768 27

In 91 of 106 adult patients with acute lymphoblastic leukemia (ALL) enrolled in the treatment protocol ALL HOVON-5 between May 1988 and October 1991, the immunophenotype of the leukemia was determined and correlated with clinical characteristics at presentation. The immunological marker analysis was performed in ten laboratories, all members of the Dutch Study Group on Immunophenotyping of Leukemias and Lymphomas (SI-HON). Undifferentiated blasts were found in four patients, 67 had B-lineage ALL, 18 had T-lineage ALL, and two had biphenotypic ALL. The age of T-lineage ALL patients was lower (mean 29.3) than that of B-lineage ALL patients (mean 35.5). Tumor mass, as expressed by leukocyte count, organomegaly, and LDH, was more pronounced in T-lineage ALL. Hemoglobin and platelet count was similar in all (sub)types. CD34 was expressed in 58% of the leukemias, but most frequently in the common B-ALL (70%). Thirteen percent of the leukemias expressed one or more markers not associated with their lineage. In this prospective study immunological data were not evaluable for 15 patients. On four of them data were not available because of dry tap, for six patients the typing was technically insufficient, and for four patients the results were unclassifiable; with one patient the marker analysis was not performed.
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PMID:Acute lymphoblastic leukaemia in adults: immunological subtypes and clinical features at presentation. 768 3

The histogenetic relationship amongst various dendritic cells of the dermis which may express markers including factor XIIIa (FXIIIa) or CD34 remains unclear. In this study we utilized a sensitive indirect immunoperoxidase staining technique to identify CD34 and FXIIIa, as well the monocyte/macrophage markers KP-1 and MAC 387 expression in a variety of cutaneous dermal tumors of mesenchymal origin to see if differential expression of CD34 vs FXIIIa exists. Tumors studied included dermatofibroma (DF) (N = 10), keloid (N = 9), atypical fibroxanthoma (AFX) (N = 3), and dermatofibrosarcoma protuberans (DFSP) (N = 7). DF were all composed of FXIIIa+ spindle-shaped and stellate tumor cells (mean score = 4.9 or > or = 75% FXIIIa+) as previously reported, but these cells rarely (< 10%) expressed CD34. Six of 7 DFSP were found to be > 75% CD34+ and FXIIIa negative, while one DFSP was negative for both CD34 and FXIIIa. In all DFSP, there were trapped FXIIIa+ cells which were distinct from the spindle-shaped tumor cells. AFX showed sparse populations of FXIIIa+ cells in the stroma (mean score = 1.33 or 10-25% positive), which were distinct from the atypical giant cells characteristic of these tumors. Keloid similarly contained trapped FXIIIa+ cells (mean score = 0.44 or < 5% positive) that were distinct from the spindle-shaped fibroblasts of the tumor mass. Dendritic and spindle-shaped cells within these tumors were consistently both KP-1 and Mac-387 negative, while all lesions studied were characterized by scattered round, histiocytic cells which were KP-1+ and/or Mac-387+ irrespective of tumor cell type.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Differential expression of factor XIIIa and CD34 in cutaneous mesenchymal tumors. 768 70


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