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

A retrospective analysis of seven patients with intraventricular neurocytoma is presented. Patient age at diagnosis ranged from 15 to 38 years (mean 24.6 years) and the male:female ratio was 6:1. Raised intracranial pressure due to hydrocephalus was the main cause of the clinical manifestations. An isodense mass with multiple intratumoral cysts and homogeneous contrast enhancement was the characteristic computerized tomography finding. The lesions commonly involved the lateral ventricle with or without extension to the third ventricle. Cerebral angiography showed homogeneous vascular staining in five patients. Magnetic resonance images revealed a mass isointense with the cerebral cortex on both T1- and T2-weighted images. Gadolinium-diethylenetriaminepenta-acetic acid-enhanced images showed homogeneous enhancement. Total removal of the tumor was possible in four patients. Pathologically, six cases were initially diagnosed as oligodendroglioma and the remaining case as ependymoma. However, immunohistochemical studies demonstrated strong positivity for neuron-specific enolase in all seven cases and for synaptophysin in five cases. On electron microscopy, three cases showed well-defined neurosecretory granules and 10-nm microtubules in their cytoplasm and cytoplasmic processes. One patient developed a recurrent tumor 18 months after surgery. The remaining six patients are free of recurrent tumors at 2 to 62 months after surgery. It is suggested that neurocytoma must be included in the differential diagnosis of intraventricular lesions, and that electron microscopic and immunohistochemical studies should be undertaken.
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PMID:Intraventricular neurocytoma: clinicopathological analysis of seven cases. 156 38

We report a case of intracystic papillary carcinoma of the male breast in a 70-year-old male Caucasian. Grossly, the tumor was a cystic lesion measuring 6 cm in diameter. It contained hemorrhagic fluid and a mural nodule with filiform projections. PAS stain with and without digestion revealed small clumps of diastase-resistant material in the cytoplasm of the neoplastic cells. Grimelius stain was positive. Immunoperoxidase stains were negative for neuron-specific enolase, S100 protein, cromogranin and synaptophysin and were positive for carcinoembryonic antigen and epithelial membrane antigen. On ultrastructural examination the neoplastic cells showed membrane-bound, dense-core secretory granules. We believe that this neoplasm, despite negative neuroendocrine markers, is a variant of mammary adenocarcinoma with endocrine differentiation, partly because of the positive Grimelius stain and partly because of the presence of electron-dense granules, which according to some authors represent lactational differentiation.
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PMID:Intracystic papillary carcinoma of the male breast. A case report (histochemical, immunohistochemical and ultrastructural study). 160 58

We describe the case of a 31-year-old woman who was first treated for a pigmented choroid plexus papilloma of the fourth ventricle. Ten year later, she developed a new tumor in the region of the cauda equina. This second neoplasm contained areas of papillary ependymoma that displayed phosphotungstic acid hematoxylin-positive glial fibers and immunoreactivity for glial fibrillary acidic and S-100 proteins. Areas of ependymoma merged with others that displayed the appearance of a paraganglioma, including lobules and nests of chief cells immunoreactive for neuron-specific enolase, synaptophysin, chromogranin, and serotonin. Satellite cells, but not chief cells, stained for glial fibrillary acidic and S-100 proteins. Electron microscopy showed features of both ependymal and paraganglionic differentiation, including intercellular lumina with microvilli, junctional complexes, cell processes with closely packed filaments, and dense core granules. Our case represents a rare example of a cauda equina neoplasm with simultaneous ependymal and paraganglionic differentiation. To our knowledge, this is the first described example of a tumor of this region showing features of both ependymoma and paraganglioma.
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PMID:Cauda equina tumor with ependymal and paraganglionic differentiation. 161 83

Three cases of periventricular neurocytomas are presented. All patients had a large but well-circumscribed, hyperdense tumor with insignificant contrast enhancement in the lateral and third ventricle, causing hydrocephalus. Calcification was present in one patient. Angiography revealed a blush tumor enhancement in two cases. Surgical removal was complete in two patients and incomplete in one. Light microscopy showed a cell pattern that resembled either ependymoma or oligodendroglioma. However, in all cases the tumor was confirmed to be a neurocytoma by immunocytochemical analysis that showed reactivity for synaptophysin and/or neuron-specific enolase in a high percentage of neoplastic cells. With respect to the literature it is concluded that neurocytomas represent an individual pathological entity of supratentorial midline tumors. Complete surgical removal without irradiation is the recommended treatment.
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PMID:Periventricular neurocytoma: a pathological entity. 161 72

This report describes an unusual medullomyoblastoma which developed in the cerebellar vermis of a 6-year-old girl. Histological investigation showed a highly cellular and predominantly undifferentiated tumor. Myogenic differentiation was prominent in clusters of large tumor cells with eosinophilic cytoplasm and immunoreactivity for desmin and myoglobin. Electron microscopy revealed the presence of immature Z-bands. Immunohistochemically, numerous cells showed incipient expression of myoblastic marker antigens, supporting the view that medulloblastomas and related primitive neuroectodermal tumors possess the potential for non-neural differentiation. In addition, there was evidence of advanced neuronal differentiation, with expression of neuron-specific enolase, synaptophysin, retinal S-antigen, and the formation of ganglioid tumor cells. Occassional neoplastic cells expressed glial fibrillary acidic protein without morphologically detectable astrocytic differentiation. Associated with the neoplasm was brain tissue containing clusters of neuronal cells and focal accumulations of immature oligodendroglia-like cells which expressed neuronal marker antigens. This unusual component resembled a hamartomatous lesion and would support the hypothesis that the cerebellar medullomyoblastoma originated from a teratomatous or malformative lesion. Alternatively, this component may constitute the end stage of advanced neuronal differentiation of a primitive neuroectodermal tumor.
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PMID:Cerebellar medullomyoblastoma with advanced neuronal differentiation and hamartomatous component. 166 56

Thirty-five selected intracranial tumors qualifying as primitive neuroectodermal tumors (PNETs) were investigated; these included medulloblastomas, cerebral neuroblastomas, pinealoblastomas, retinoblastomas, polar spongioblastomas, ependymoblastomas. For control purposes 11 tumors, including glioblastomas (small cell, spongioblastic variants), one anaplastic astrocytoma (astroblastic component), anaplastic oligo-astrocytomas, gangliogliomas, one primary melanoblastoma, and one pineal germinoma, were also studied. Six neuronal markers, i.e., synaptophysin, chromogranin A, neuron-specific enolase (NSE), neurofilament protein (NFP) (160 kDa, 200 kDa, 70 and 200 kDa), and six other markers (glial fibrillary acidic protein, S-100 protein, vimentin, myoglobin, desmin, cytokeratin) were investigated immunohistochemically. A certain recapitulation of the ontogenetic development of neuronal differentiation in PNETs is given by the fact that chromogranin A immunoreactivity can regularly be seen already in poorly differentiated neurons and synaptophysin in well-differentiated ones. Immunostaining for NFPs showed different results depending on the subunit investigated. NSE reaction gave different results even within the single tumor groups. This study is, to the best of our knowledge, the first attempt to evaluate and compare, by combined morphological and immunohistochemical methods, PNETs without and with different stages of cellular differentiation with the stepwise differentiation of the human embryonic neuroectoderm.
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PMID:Immunohistochemical characterization of primitive neuroectodermal tumors and their possible relationship to the stepwise ontogenetic development of the central nervous system. 2. Tumor studies. 166 31

A new permanent cell line (GRU-1) derived from the lymph-node metastasis of a human epithelioid sarcoma was established in tissue culture. Immunohistochemically, the original tumor had exhibited an intriguing potential for multidirectional differentiation with features of mesenchymal, epithelial and neural differentiation, evidenced by the co-expression of vimentin, cytokeratins and neurofilament proteins, respectively. This capability for multidirectional differentiation was fully preserved in the cultured cells. GRU-1 tumor cells proved to be uniformly positive for vimentin and a considerable proportion of the tumor cells exhibited a positive reaction for cytokeratins and neurofilament proteins. The neural markers neuron-specific enolase (NSE) and synaptophysin were observed in a small proportion of GRU-1 cells. Ultrastructurally, GRU-1 cells showed desmoplastic activity in vitro, being enmeshed by collagen fibrils. DNA distribution, as studied by flow cytophotometry, revealed DNA-diploidy (DNA index = 1) and a G0/G1-proportion of 70.5%. After heterotransplantation in nude mice, GRU-1 tumor cells expressed vimentin and cytokeratin only, whereas the neural markers could not be further demonstrated.
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PMID:Multidirectional differentiation in a newly established human epithelioid sarcoma cell line (GRU-1) with co-expression of vimentin, cytokeratins and neurofilament proteins. 168 30

We studied eight clear cell tumors of the lung (CCTL) to better define their clinical, immunohistochemical, and ultrastructural features, and to clarify their distinction from other neoplasms, particularly metastatic renal cell carcinoma. Patients ranged in age from 31 to 67 years (mean, 51 years). Seven patients had clinically benign, asymptomatic lesions measuring less than 2 cm in diameter that were devoid of necrosis. The eighth patient had a symptomatic, partially necrotic CCTL 4.5 cm in diameter that metastasized to the liver and peritoneum; the patient died of tumor 17 years after diagnosis. Ultrastructural study of seven CCTL showed interdigitating cell processes (all cases), primitive cell junctions (five of seven cases), intracytoplasmic glycogen (all cases), and rare dense core granules (two of seven cases). Immunohistochemically, paraffin-embedded sections from all eight CCTL were negative for cytokeratin (CK), epithelial membrane antigen (EMA), chromogranin, and vimentin. Focal staining was seen for S-100 protein (three of eight cases), neuron-specific enolase (three cases), synaptophysin (one case), and Leu 7 (one case). Although these findings suggest that at least some CCTL exhibit neuroendocrine differentiation, the tumor's histogenesis remains uncertain. Of more practical importance, the combined absence of CK, EMA, and vimentin in formalin-fixed, paraffin-embedded CCTL virtually precludes confusion with renal cell carcinoma. Although traditionally considered benign, CCTL larger than 2 cm that are symptomatic, and focally necrotic should be regarded as potentially malignant neoplasms.
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PMID:Clear cell tumor of the lung. A clinicopathologic, immunohistochemical, and ultrastructural study of eight cases. 202 21

A histologic and immunohistochemical study was carried out in 23 unselected nonantral gastric carcinoids and their precursor lesions classified according to Solcia et al. None of the patients showed Zollinger-Ellison syndrome. Two variants of carcinoids showing distinctive pathologic and pathogenetic characteristics were identified on the basis of presence or absence of associated chronic atrophic gastritis type A (A-CAG). Chronic atrophic gastritis type A was found in 19 cases showing either single or multiple neoplasms, tumor extension limited to the mucosa or submucosa, consistent endocrine cell precursor changes in extratumoral mucosa, and consistent hypergastrinemia and/or G cell hyperplasia. Associated precursor lesions were only hyperplastic in all but two cases with single carcinoids whereas they were also dysplastic in all but one case with multiple carcinoids. The four tumors arising in nonatrophic mucosa were all single, more aggressive, and not associated with extratumoral endocrine cell proliferations or with signs of gastrin hypersecretion. Tumor cells were diffusely immunoreactive for chromogranin A and synaptophysin but usually negative for chromogranin B or HISL-19. Scattered serotonin cells were found in ten carcinoids. They were more frequent in infiltrating than in intramucosal tumors as were the less represented pancreatic polypeptide cells whereas the reverse was found for alpha-subunit-containing cells. These results are of relevance for tumor pathogenesis and may provide the rationale for a less aggressive therapeutic approach in the patients.
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PMID:Gastric carcinoids and their precursor lesions. A histologic and immunohistochemical study of 23 cases. 170 55

We studied by immunohistochemistry 26 retinoblastomas in situ using monoclonal antibodies specific for the neuron-associated class III beta-tubulin isotype (h beta 4), microtubule-associated protein 2 (MAP2), and synaptophysin. Anti-h beta 4 and anti-MAP2 immunostaining was consistently obtained in the Flexner-Wintersteiner rosettes, in fleurettes, in Homer Wright (neuroblastic) rosettes, and also variably among poorly differentiated tumor cells. A similar pattern of antisynaptophysin immunopositivity was seen, but was especially pronounced in the adluminal borders of cells forming the Flexner-Wintersteiner rosettes. The demonstration of h beta 4, MAP2, and synaptophysin epitopes in poorly differentiated and maturing neoplastic phenotypes in retinoblastomas attests to the neuronal character of this embryonal tumor. Immunoreactivity toward h beta 4 and MAP2 epitopes by poorly differentiated neoplastic cells may indicate early neuronal commitment in retinoblastoma. The consistent immunostaining of Flexner-Wintersteiner rosettes with monoclonal antibodies to h beta 4 and MAP2 is in keeping with the previous ultrastructural documentation of microtubules with a neuronal-like spatial organization present in the cells of these structures.
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PMID:Neuron-associated class III beta-tubulin isotype, microtubule-associated protein 2, and synaptophysin in human retinoblastomas in situ. Further immunohistochemical observations on the Flexner-Wintersteiner rosettes. 170 86


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