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

Eight cases of central neurocytomas were studied by immunohistochemistry and electron microscopy. Seven tumors were located in the lateral ventricles and one in the subependymal region. All but one patient had a favorable postoperative course. The tumors were composed of small uniform cells possessing amitotic round nuclei with frequent perinuclear halos, a few Homer Wright rosettes and no ganglion cells; an appearance resembling that of oligodendroglioma. Immunohistochemical studies disclosed neuron-specific enolase and Leu-7 positivity in all tumors, S-100 protein-positive cells were found in six, while glial fibrillary acidic protein--and vimentin-positive cells were confined to the blood vessels. Myelin basic protein as well as neurofilament were not detected in the tumors. Synaptophysin-positive areas were seen in one tumor. Ultrastructural examination showed distinctive neuronal tumor cells which had a cytoplasm with sparse dense-core vesicles and thin cell processes containing parallel microtubules. They were classified into three different types of tumor cells according to the extent of differentiation. The most consistent finding for histological diagnosis was the presence of typical or abortive synapses with clear and dense-core vesicles. Additionally, synaptophysin may be a specific marker for some central neurocytomas.
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PMID:Central neurocytoma: immunohistochemical and ultrastructural study. 202 45

A surgically resected medulloblastoma of the left cerebellum in a 42-year-old man contained numerous mature fat cells; many of these adipocytes expressed glial fibrillary acidic protein (GFAP), S-100 protein, and vimentin as seen by immunocytochemistry. The cellular parts of the tumor showed varying immunoreactivities for GFAP, S-100 protein, neuron-specific enolase, and synaptophysin. It is concluded that this tumor exhibits a unique spectrum of differentiation along multiple lines, including transformation of neuroectodermal cells to fat cells. The significance of this new type of differentiation in primitive neural tumors remains to be elucidated.
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PMID:Lipomatous differentiation in a medulloblastoma. 202 51

We report a case of metastatic thymic neoplasm occurring in a 62-year-old Caucasian man. The tumor was polymorphic, with intimately admixed carcinoid, sarcomatous and undifferentiated components. Sarcomatous cells were spindle-shaped and immunoreactive for vimentin, actin and desmin. Carcinoid cells reacted for cytokeratin as well as with a panel of general neuroendocrine markers, including chromogranins A and B, synaptophysin, protein gene product (PGP) 9.5, neuron specific enolase (NSE), Leu 7 and Grimelius' silver. The endocrine nature of the latter cells was confirmed by ultrastructural evidence of abundant electron-dense granules 100 to 300 nm in size. Among the various hormones investigated immunohistochemically only the alpha chain of human chorionic gonadotropin (alpha-hCG) was detected in tumor cells. The neoplasm recurred after surgical resection and caused a typical carcinoid syndrome with skin flushing and increased urinary 5-hydroxyindolacetic acid (5-HIAA). The diagnosis of multidirectional thymic carcinoma with two lines of differentiation, of carcinoid and sarcomatoid type, was made.
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PMID:Multidirectional carcinoma of the thymus with neuroendocrine and sarcomatoid components and carcinoid syndrome. 206 96

Three patients with histopathologically proven orbital metastatic lesions from a carcinoid tumor are reported. Computed tomography (CT) disclosed a well-circumscribed orbital mass in two of three cases. Each tumor was studied by both light and electron microscopy as well as immunohistochemistry and DNA flow cytometry. A review of the literature discloses the relatively rare occurrence of carcinoid tumors metastasizing to the eye and orbit. With the exception of one case, the reported metastatic carcinoid tumors to the uvea all developed from primary bronchial carcinoids. In contrast, the vast majority of the reported orbital metastases arose from ileal carcinoids. Immunohistochemical markers such as chromogranin A, synaptophysin, and serotonin have proven to be useful diagnostic tools in evaluating carcinoid tumors. Furthermore, DNA flow cytometry may be of prognostic value in patients with metastatic carcinoid tumor.
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PMID:A clinicopathologic study of three carcinoid tumors metastatic to the orbit. Immunohistochemical, ultrastructural, and DNA flow cytometric studies. 210 98

In the past, contradictory results have been reported concerning the specificity of neuronal or glial cell markers. However, we have investigated this aspect in a large group of more than 550 brain tumors (among them 60 medulloblastomas). These contradictions can easily be explained by considering two basic facts. First, every neoplastic cell population, especially in embryonic tumors, diffusely infiltrates the brain tissue: non-neoplastic cells, intermingled with tumor cells, can therefore give rise to immunohistochemical and histogenetic misinterpretations. Second, different cell markers can be expressed by one and the same cell (e.g., GFAP, NSE, vimentin), making nosological interpretation of the tumor difficult, impossible, or at best rather subjective. Clear-cut marker positivity is mostly found in the differentiated tumors for which the nosological classification is already clear by the usual histological methods. Only synaptophysin seems to be a reliable marker for neurogenic cells. In embryonic brain tumors (so-called PNET), no correlations between the presence of a given cell marker and the biological behavior of the tumor have so far been detected.
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PMID:Immunohistochemistry in childhood brain tumors: what are the facts? 211 27

A simplified method of processing of fine needle aspirates for paraffin miniblocks suitable for both morphologic and immunocytochemical evaluation is described. Aspirates were fixed in ethanol at 4 degrees C, dehydrated in acetone and xylene and embedded in paraffin (58 degrees C). All steps were carried out in a single Eppendorf centrifuge tube; the total process took less than four hours. Deparaffinized sections were stained using the alkaline phosphatase-antialkaline phosphatase technique with monoclonal and conventional antibodies helpful in the differential cytologic diagnosis of alcohol-fixed aspiration biopsy specimens. Antibodies to keratin, vimentin, desmin, neurofilaments, glial fibrillary acidic protein, leukocyte-common antigen, synaptophysin and immunoglobulin kappa and lambda light chains reacted positively on the miniblock material. Since the paraffin miniblocks combine the histologic pattern of the tumor with the differentiation-specific information provided by immunocytochemistry, their use can improve the accuracy of tumor typing in aspirates.
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PMID:Immunocytochemistry on fine needle aspirates in paraffin miniblocks. 214 Apr 87

Biopsy specimens obtained from eight patients with lung cancer were tested for content of somatostatin receptors by autoradiography. Somatostatin receptors were detected in two of three patients with small cell lung cancer (SCLC) but in none of five patients with non-small cell lung cancer (NSCLC) including adenocarcinoma (two), squamous cell carcinoma (two), and bronchoalveolar carcinoma (one). In those with SCLC, specific somatostatin receptor binding was evidenced only in tumor foci and not in surrounding stroma or normal lung parenchyma. Further tissue characterization by immunoperoxidase staining with the pancytokeratin monoclonal antibody, mAB-lu-5, revealed labeling to all of the NSCLC but to none of the SCLC specimen. Selective immunoreactivity was detected in both the SCLC and the NSCLC specimen to chromogranin and neuron-specific enolase (NSE) whereas none of the specimen had detectable immunostaining to somatostatin, bombesin, serotonin, adrenocorticotropic hormone, neurofilament, calcitonin, and synaptophysin. The identification of somatostatin receptors in primary human lung cancer may have a bearing on the biology of this disease and perhaps on the clinical application of somatostatin analogues in patients with SCLC.
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PMID:Identification of somatostatin receptors in human small cell lung carcinoma. 217 45

To further characterize the clinicopathologic spectrum of colorectal neuroendocrine neoplasia, 24 carcinomas with neuroendocrine differentiation were subtyped as either small cell neuroendocrine, oat cell variant (six cases), small cell neuroendocrine, intermediate variant (16 cases), or moderately differentiated neuroendocrine carcinoma (two cases). Five oat cell variants, 14 intermediate variants, and two moderately differentiated tumors were studied with antibodies to cytokeratin, vimentin, epithelial membrane antigen (EMA), neuron-specific enolase (NSE), chromogranin (CRG), synaptophysin (SYN), neurofilament, S-100 protein, carcinoembryonic antigen (CEA), and Leu-7. All tumors were immunoreactive for cytokeratin and the majority were also positive for EMA and NSE. Positivity for specific neuroendocrine markers was uncommon, with SYN reactivity noted in one oat cell variant and four intermediate variants, and CRG positivity observed in four intermediate variants and one moderately differentiated tumor. Ultrastructural analysis of four oat cell, eight intermediate, and one moderately differentiated tumor revealed neurosecretory-type, dense-core granules in all lesions, except two oat cell variants studied from paraffin-retrieved material. Hepatic and regional lymph node metastases were noted in five of six oat cell, eight of 16 intermediate, and two of two moderately differentiated tumors. Of 17 patients with follow-up (four oat cell, 11 intermediate, and two moderately differentiated tumors), only two individuals were alive after 1 year. There were no detectable differences in survival or response to treatment between morphologic subtypes. The prognosis of colorectal neuroendocrine carcinoma appears worse than for adenocarcinoma of comparable stage. Their distinction is thus warranted, especially in regard to the intermediate variant and moderately differentiated tumors, which may be potentially misinterpreted as forms of adenocarcinoma.
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PMID:Neuroendocrine carcinoma of the colon and rectum. A clinicopathologic, ultrastructural, and immunohistochemical study of 24 cases. 217 27

A continuous tumor cell line (LAP-35) was established from a primitive neuroectodermal tumor of bone from the right tibia of a 12-year-old female. The neural character of the cell line was documented by the spontaneous growth of neurites and by the presence of several neural markers, including neuron-specific enolase (NSE), S-100 protein, neurofilaments, chromogranin A, synaptophysin and positivity to monoclonal antibodies UJ127.11, UJ13A, UJ181.4. Cell-sorter analysis showed a high expression of nerve growth factor receptor (NGFr) and major histocompatibility complex class I-related molecules. A unique cytogenetic profile was observed, including a reciprocal chromosomal translocation (rct) 11:22 (q24;q12), typically associated with Ewing's sarcoma and neuroepithelioma, and deletion of the short arm of chromosome 1 (lp-), otherwise a feature of neuroblastoma. N-myc proto-oncogene was neither amplified nor expressed, whereas the expression of c-myc was documented by northern blot analysis. These features distinguish this new cell line from previously reported neuroectodermal cell lines, identifying LAP-35 as a unique model of a group of neural bone tumors that share characteristics of neuroblastoma as well as neuroepithelioma.
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PMID:Establishment and characterization of a primitive neuroectodermal tumor of bone continuous cell line (LAP-35). 217 80

Three patients with a recently described tumor of neuronal origin, intraventricular neurocytoma, are presented. These tumors occur as intraventricular lesions in young patients, and the prognosis after surgical treatment is favorable. The initial pathological diagnosis of intraventricular neurocytoma may be difficult because of the striking resemblance of these tumors to oligodendroglioma and, to a lesser extent, ependymoma on light microscopic examination. Despite the use of wide-ranging panels of monoclonal antibodies, previous authors have not found any characteristic immunohistochemical staining patterns, but in our three patients, the use of synaptophysin, glial fibrillary acidic protein, and Leu-7 demonstrated staining patterns that may be useful in the diagnosis of this tumor. The monoclonal antibody Ki-67 was used to stain one tumor and showed a low cell proliferation rate. We have reviewed the clinical, radiological, and pathological features of these 3 patients and 17 previously described patients in an attempt to determine the important diagnostic features of intraventricular neurocytoma. Intraventricular neurocytoma should be considered in any young patient with symptoms of raised intracranial pressure and radiological evidence of an intraventricular lesion. Pathological diagnosis requires the use of electron microscopy to show features of neuronal differentiation; however, immunohistochemical demonstration of a neuronal phenotype is also a useful adjunct to diagnosis. Failure to use specialized techniques for pathological diagnosis will lead to misdiagnosis of these lesions as oligodendrogliomas, as was the initial diagnosis in 2 of our patients before review.
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PMID:Intraventricular neurocytoma: a clinical and pathological study of three cases and review of the literature. 219 40


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