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

Mesenchymal chondrosarcoma is an uncommon small-cell neoplasm of bone and soft tissue, the chondrogenic nature of which has been generally accepted. However, the phenotypic attributes of the small-cell population in this neoplasm have not been well characterized, and its relationship to "precartilage mesenchyme" remains unclear. In an attempt to address this issue, we performed an immunohistochemical analysis of nine cases, using antibodies to vimentin, S100 protein, Leu-7 antigen, neuron-specific enolase, synaptophysin, desmin, muscle-specific actin, cytokeratin, and epithelial membrane antigen, and the avidin-biotin-peroxidase complex (ABC) method. The small cells of mesenchymal chondrosarcoma failed to express S100 protein, whereas all components of the tumors (small cells, lacunar chondroblasts, and chondroid matrix) stained for Leu-7 antigen in six cases. Neuron-specific enolase was identified in the small cells of four cases and in the lacunar cells of seven. None contained desmin, actin, cytokeratin, epithelial membrane antigen, or synaptophysin. The immunophenotype of mesenchymal chondrosarcoma resembled that of embryonic cartilage and thus did not contradict the premise that this tumor was the neoplastic counterpart of fetal chondroid tissues. However, immunohistologic studies are not overly helpful in the differential diagnosis between mesenchymal chondrosarcoma and other small round cell lesions.
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PMID:Mesenchymal chondrosarcoma. An immunohistochemical study. 220 75

We describe a giant cell tumor of the pancreas composed of a mixture of osteoclastic and pleomorphic cell types. This rare tumor had a unique immunohistochemical profile. Both types of tumor giant cells stained for vimentin, alpha-1-antitrypsin, alpha-1-antichymotrypsin, synaptophysin, muscle actin, and neuron-specific enolase, but not for epithelial markers. Electron microscopy showed cells which resembled primitive fibroblasts and osteoclast with no epithelial features. These findings are most consistent with mesenchymal differentiation. The extensive homologies in immunohistochemical staining of both osteoclastic and pleomorphic giant cells in this case indicates that these cells are histogenetically related.
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PMID:Giant cell tumor of the pancreas of mixed osteoclastic and pleomorphic cell type: evidence for a histogenetic relationship and mesenchymal differentiation. 222 26

A one year old boy was found to have a large tumor encompassing the pineal region and extending towards the third and lateral ventricles and quadrigeminal plate. The tumor was composed mostly of small, undifferentiated cells. Some small cells were arranged in Flexner-Wintersteiner rosettes and a few displayed fleurettes. The tumor contained immature cartilage and skeletal muscle and numerous clusters of pigmented epithelial-like cells which, histologically, resembled those found in melanotic neuroectodermal tumors of infancy (retinal anlage tumors) and retinal or ciliary epithelium. Immunologic stains demonstrated neurofilaments synaptophysin and retinal S-antigen in some of the small cells and transthyretin in some of the epithelial-like cells. The findings indicate that certain primary pineal parenchymal tumors have features in common with tumors of the ocular medullary epithelium.
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PMID:Primitive pineal tumor with retinoblastomatous and retinal/ciliary epithelial differentiation: an immunohistochemical study. 226 1

Merkel cells are clear oval cells in the epidermis and outer root sheaths of hair follicles, which are probably of epithelial origin, share ultrastructural features with neuroendocrine cells, and are found in association with touch receptors. In the eyelid, they occur singly in the epidermis and external root sheaths of hairs and eyelashes, and in specialized touch spots alternating with eyelashes. Their typical electron microscopical and antigenic features include dense-core granules, intranuclear rodlets, spinous processes, and a positive reaction for specific cytokeratins, epithelial membrane antigen, neuron-specific enolase, chromogranin and synaptophysin. Merkel cell carcinoma probably develops from precursor cells which give rise to keratinocytes and Merkel cells, and nearly one out of ten Merkel cell carcinomas occur in the eyelid and periocular region. They tend to be bulging lesions near the lid margin of elderly patients, reddish in color, and erythematous with telangiectatic vessels. The diagnosis is based on the frequent presence of neurofilaments and paranuclear aggregates of intermediate filaments in addition to features typical of normal Merkel cells. The tumor often mimics lymphoma or undifferentiated carcinoma and frequently invades lymphatic vessels. One third of Merkel cell carcinomas recur, almost two thirds give rise to regional node metastases, and up to one half metastasize widely and result in death. Initial treatment should be prompt and aggressive, with wide resection and routine postoperative irradiation. Although metastatic lesions often respond to radiation therapy and cytostatic drugs, these treatments are mainly of palliative value.
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PMID:The Merkel cell and associated neoplasms in the eyelids and periocular region. 227 47

The nuclear DNA content of 17 pancreatic neuroendocrine tumors was measured from paraffin-embedded tissue with flow cytometry. The tumors were classified by immunostaining with antisera for synaptophysin, insulin, gastrin, glucagon, pancreatic polypeptide, somatostatin, and vasoactive intestinal polypeptide. Eight (47%) of the 17 tumors were aneuploid, and two (12%) were multiploid (had two aneuploid stemlines of cells). Seven of the eight insulinomas, one of the four gastrinomas, and two of the four nonspecified neuroendocrine tumors had an abnormal nuclear DNA content. The DNA indices of the aneuploid and multiploid cases ranged from 1.13 to 1.93, and three cases had a DNA index greater than 1.50. During the follow-up for up to 16 years (mean, 7 years), one patient with diploid nonspecified tumor died of the disease, another patient with a multiploid gastrinoma had metastatic disease develop, and a third patient with a multiploid nonspecified tumor was alive with the disease. The authors conclude that many neuroendocrine tumors of the pancreas have an abnormal nuclear DNA content as measured by DNA flow cytometry. DNA multiploid pancreatic neuroendocrine tumors may be associated with a less favorable clinical course, but this needs to be confirmed in additional studies.
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PMID:DNA ploidy in pancreatic neuroendocrine tumors. 234 35

The authors report the clinical, radiological, and pathological findings in three cases of paraganglioma of the cauda equina. In one case, magnetic resonance imaging and neurochemical study results are described. No specific identifying features were encountered either clinically or radiologically that were helpful in making a distinction between this and other more common tumors at this site such as ependymoma or neurofibroma. At surgery, these neoplasms were well-circumscribed red fleshy tumors. Histological examination of one paraganglioma showed a superficial resemblance to ependymoma, and this may be particularly true on initial assessment by frozen section or smear. The use of electron microscopy and immunohistochemical demonstration of synaptophysin in these tumors allowed a confident diagnosis to be made. Neurochemical assessment in one case showed very high levels of serotonin and a turnover of dopamine similar to that of human cerebral cortex. Paraganglioma of the cauda equina is an uncommon tumor with just over 50 cases reported in the world literature. The clinical course of these tumors is benign and they should be completely removed at surgery to prevent later recurrence.
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PMID:Paraganglioma of the cauda equina. Report of three cases. 238 84

Seven cases of alveolar soft part sarcomas (ASPSs) were studied immunohistochemically for the presence of a number of differentiation markers in an attempt to define the cellular nature of this tumor. Desmin-positive tumor cells were found in three and muscle actin-positive cells in four cases when studied in formaldehyde-fixed and paraffin-embedded material. In one case studied in frozen sections, focal desmin positivity but no other intermediate filaments were found. Immunostaining for synaptophysin, a general neuroendocrine marker, was negative in all cases. All tumors were positive with a monoclonal antibody NK1C3, which consistently stains melanomas, and three cases showed significant numbers of S-100 protein-positive tumor cells, but immunostaining with HMB-45, a melanoma-specific monoclonal antibody, was negative in all cases. However, several rhabdomyosarcomas studied for NK1C3 and S-100 protein for comparison were also at least focally positive. Electron microscopic examination, performed in three cases, showed uniform paucity of all kinds of filaments in the tumor cells of ASPS, and it specifically failed to reveal any signs of smooth or striated muscle cell differentiation. Thus, the results of the present study do not unequivocally define the nature of ASPS but speak against its paraganglionic character and present evidence for muscle cell differentiation.
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PMID:Alveolar soft part sarcoma. Immunohistochemical evidence for muscle cell differentiation. 207 82

The various classifications of brain tumors are characterized by a rather disturbing diversity of tumor designations. This diversity results from the heterogeneity of human brain tumors, but also from the lack of knowledge about the histogenesis of many of these tumors. The histogenesis of some of the different types of tumor could be resolved by the application of electron microscopical studies. New aspects are gained from immunohistochemical investigations using mono- and polyclonal antibodies against intermediate filaments (GFAP, vimentin, cytokeratins), neuron-specific enolase (NSE), protein S-100, carcinoembryonic antigen (CEA), myelin-associated glycoprotein (Leu 7), synaptophysin and nuclear proliferating antigen (Ki-67). The present paper gives a survey on how immunohistochemistry can be advantageously used in the diagnosis of brain tumors.
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PMID:[Immunopathology of brain tumors]. 244 48

Fifty-four formalin-fixed and paraffin-embedded intraocular retinoblastoma specimens and three human eyes enucleated because of orbital tumors were studied for the presence of synaptophysin, a neuron-associated integral membrane glycoprotein of presynaptic vesicles, by using the monoclonal antibody SY38. Normal human brain was used as control. In the human retina, synaptophysin-like immunoreactivity was present in both plexiform layers, but could not be detected in neuronal perikarya. However, in reactive retinas present in retinoblastoma eyes, synaptophysin was often observed in perikarya and processes of photoreceptors. Positive neoplastic cells were found in 45 of the 54 retinoblastomas. Differentiated tumors tended to contain greater numbers of positive cells than undifferentiated ones, a third of which were entirely negative. Identical immunoreactivity was seen in frozen specimens from human retina and from three retinoblastomas. Using Western blotting, a major polypeptide comigrating with human brain synaptophysin was detected in human retina, and a similar but slightly slower migrating band in retinoblastoma. The results support a primarily neuronal origin for this tumor and point to the possibility that synaptic elements, previously observed in a few cases, may be more frequent in retinoblastoma than had been thought.
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PMID:Synaptophysin in the human retina and retinoblastoma. An immunohistochemical and Western blotting study. 246 54

Twenty-nine paragangliomas of the head and neck region including 20 glomus jugulare (GJ) and nine carotid body (CB) tumors were evaluated for the presence of neuroendocrine and intermediate filament antigens. Immunohistochemistry on formalin-fixed, paraffin-embedded tissue was used to identify: S-100 protein (S-100); neuron-specific enolase (NSE); chromogranin A (CHA); serotonin (SER); synaptophysin (SYN); cytokeratin (CK); neurofilament (NF); desmin (DES); vimentin (VIM); and glial fibrillary acidic protein (GFAP). S-100 protein staining of sustentacular cell nuclei and cytoplasm was found in all tumors and was present in chief cells in 4 of 20 GJ and 3 of 9 CB tumors. All tumors stained with at least three neuroendocrine markers (29 of 29 NSE, 28 of 29 SYN, 26 of 29 CHA, 25 of 29 SER). CK was detected in 2 GJ and 1 CB tumor using anticytokeratins AE 1/3 and CAM 5.2. Neurofilament protein could not be demonstrated in fixed material, and all tumors were negative for GFAP and desmin. Vimentin was inconsistently detected in chief and sustentacular cells. We conclude that, in formalin-fixed material, paragangliomas have S-100 protein staining of sustentacular cells with chief cells containing antigens associated with neuroendocrine differentiation. The presence of CK in some paragangliomas is consistent with recent tissue culture studies demonstrating immunoblot confirmation of CK in pheochromocytomas and represents a potential source of immunohistologic misinterpretation in diagnosis, unless a panel of markers is utilized.
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PMID:Paragangliomas of the head and neck: immunohistochemical neuroendocrine and intermediate filament typing. 246 85


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