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

Experiments were performed to study the earliest changes and their sequence in the development of malignant tumors following implantation of 10 mg of nickel subsulfide (Ni3S2) into the right quadriceps muscle of seven male Fischer rats. Biopsies were performed when nodules reached one to three mm, and, later, when they were five to seven mm, and, finally, at sacrifice, to confirm the fully developed tumor pattern. Light microscopy of the earliest samples showed groups of cells clumped and scattered among degenerating muscle fibers. Mitoses were seen and inflammatory cells were not a feature. Electron microscopy showed individual degenerating muscle fibers, but also cells with characteristic features of myofibroblasts. In many cells osmium, dense fragments suggestive of crystalline material, were seen in the cytoplasm and nuclei. In the second set of biopsy material, myofibroblasts with well defined and dilated rough endoplasmic reticulum, intracellular membrane-bound collagen, and microfilaments with focal "dense bodies" were numerous. Mitoses were frequent. Immunohistochemistry showed strongly positive reaction to Vimentin and muscle-specific Actin in the tumor cells. In the fully developed tumors, the previously described typical storiform cell pattern with spindle and spheroidal cells with frequent mitoses was seen. Vimentin and muscle-specific Actin stains were strongly positive. The long latent period, the evidence of cell degeneration, necrosis, foreign material (probably of nickel composition), cell invasion, and subsequent rapid myofibroblast-type cell development, proliferating to malignant tumors highly suggestive of malignant fibrous histiocytoma, seem to suggest an epigenetic form of carcinogenicity of cytotoxic variety. Whether the tumor cells derive from transformed myofibrils or from activated pluripotential mesenchymal cells, or from both, remains in doubt.
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PMID:The mechanism of malignant tumor induction by nickel subsulfide. 246 16

Twenty-five rhabdomyosarcomas (RMSs), including 12 alveolar and 13 embryonal types, were immunohistochemically studied for the presence of different classes of intermediate filament proteins and muscle actins (MAs). For the most part, formaldehyde-fixed and paraffin-embedded tissue was used in immunostaining. All RMSs showed desmin and MAs, usually in a major portion of tumor cells. The number of MA-positive cells was sometimes higher than that of desmin-positive cells. Vimentin was present in all tumors studied in frozen sections. Eight of 12 alveolar RMSs showed small number of cytokeratin-positive neoplastic cells. Cytokeratin-positive cells were present less commonly in embryonal RMS (3/13 cases). The 68-kD neurofilament protein was found in frozen sections of two embryonal RMSs. The cytokeratin and neurofilament immunostaining could be reproduced by immunofluorescence technique. In addition, we studied three childhood sarcomas, which showed abundant desmin and MA immunostaining but did not conform to the ultrastructural criteria of RMS. Scattered cytokeratin-positive cells were found in two of these tumors, and neurofilaments were found in the two cases for which frozen sections were available. The results show that typical RMS may demonstrate immunohistological pleomorphism with cytokeratin and neurofilament immunoreactivity suggesting the presence of multidirectional differentiation. In addition, there are tumors that by morphology look like RMS and have muscle cell markers but cannot be verified as RMS by electron microscopy; also, these tumors seem to show immunohistological pleomorphism. The presence of nonmyoid markers in RMS should be considered when making immunohistological diagnosis of soft tissue sarcomas.
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PMID:Immunohistochemical spectrum of rhabdomyosarcoma and rhabdomyosarcoma-like tumors. Expression of cytokeratin and the 68-kD neurofilament protein. 246 53

Immunohistochemical analysis of 30 paraffin-embedded astrocytic neoplasms was performed to correlate the expression of intermediate filament proteins with histologic subtype. Each tumor was studied with monoclonal antibodies to keratin, vimentin, desmin, 200-kd neurofilament protein, and glial fibrillary acidic protein (GFAP). Immunoreactivity with the anti-keratin monoclonal antibodies AE1 and AE3 was demonstrated in 24 cases (80%) including 4 of 6 (66%) well-differentiated astrocytomas (WDAs), 10 of 12 (83%) anaplastic astrocytomas (ANAs), and 10 of 12 (83%) glioblastomas multiforme (GBMs). These cases were further studied with the monoclonal antikeratin antibodies 34 beta E12 and 34 beta H11. Of the 24 AE1/AE3-positive cases, 14 (58%) reacted with 34 beta E12. None of the cases was reactive with 34 beta H11. Vimentin expression was demonstrated in 24 cases (80%), including 2 of 6 (33%) WDAs, 11 of 12 (92%) ANAs, and 11 of 12 (92%) GBMs. Coexpression of keratin and vimentin was observed in 20 cases (67%), including 2 of 6 WDAs, 9 of 12 (75%) ANAs, and 9 of 12 (75%) GBMs. Immunoreactivity with GFAP antibody was present in all 30 (100%) cases, but none of the tumors was reactive with antibodies to desmin or 200-kd neurofilament protein. These findings demonstrate that expression of both keratin and vimentin intermediate filaments is common in astrocytic neoplasms regardless of histologic grade.
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PMID:Intermediate filament expression in astrocytic neoplasms. 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

Six cases of adenoid cystic carcinoma (ACC) of the breast were reviewed. Immunohistochemical studies were carried out for actin, S-100 protein, EMA, keratin, CEA, vimentin, NSE, alpha-lactalbumin, and lysozyme. Fine needle aspiration biopsy smears of five patients were also reexamined. Patients were treated by tumorectomy, quadrantectomy, or modified radical mastectomy. Axillary dissection was carried out in five cases, with negative lymph nodes in all. Five patients are alive without evidence of disease from 1 year 10 months to 13 years 4 months following surgery. One patient died 7 1/4 years after mastectomy, without evidence of disease. Histologically, a diagnostic biphasic cellular pattern was seen in all cases. In addition, several unusual features were encountered in some cases: squamous metaplasia, stromal myxoid pseudocartilaginous foci, and well-formed neoplastic ducts. Actin and/or S-100 protein were variably positive in all cases. The reaction was usually present in occasional basaloid cells predominantly at the periphery of neoplastic structures. Keratin, EMA, and CEA immunostaining disclosed ductal type cells in all cases. Vimentin was positive in four cases, usually in many basaloid cells. Aspiration cytology was suspicious in two cases and yielded a definitive diagnosis of ACC in three cases. Cytologic diagnosis was based on cellular morphology and on the presence of characteristic globoid structures. Immunohistochemical results show that in ACC dual myoepithelial-ductal differentiation occurs but is relatively limited. Most of the tumor cells are not differentiated ("indifferent" cells) and often express strong vimentin positivity. Such cells are regarded as precursor cells for either differentiated element. Unusual metaplastic changes in breast ACC suggest a possible relation with pleomorphic adenoma-type tumors, and this might be of prognostic significance.
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PMID:Adenoid cystic carcinoma of the breast: a histologic, cytologic, and immunohistochemical study. 247 45

Formalin-fixed, paraffin-embedded sections of 59 ultrastructurally confirmed nerve sheath tumors (NSTs) that included 27 benign schwannomas, five neurofibromas, and 27 malignant schwannomas were studied by the avidin-biotin-peroxidase complex method using antibodies directed against glial fibrillary acidic protein (GFAP), keratin, S-100 protein, vimentin, and desmin. GFAP was expressed by 33% of the benign schwannomas, 40% of the neurofibromas, and 7% of the malignant schwannomas. Keratin was expressed by 7% of the benign schwannomas and 4% of the malignant schwannomas. S-100 protein was expressed by 100% of the benign NSTs and by 40% of the malignant schwannomas. Vimentin was observed in 100% of the benign NSTs and in 85% of the malignant schwannomas. None of the cases stained for desmin. GFAP and cytokeratin expression could not be predicted on the basis of tumor light microscopy or ultrastructure. These findings are of practical importance in routine surgical pathology, particularly with respect to the differential diagnosis of gliomas located in the central nervous system and in immunohistochemical studies of peripherally located, poorly differentiated neoplasms.
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PMID:Glial fibrillary acidic protein and keratin expression by benign and malignant nerve sheath tumors. 247 42

Ovarian endometrioid carcinomas resembling sex cord-stromal tumors (ECSCSs) may simulate Sertoli cell tumors, Sertoli-Leydig cell tumors (SLCTs), and adult granulosa cell tumors (AGCTs), both clinically and pathologically. Differing clinical features and histologic findings are almost always successful in distinguishing these tumor types, although in some cases the differential diagnosis is difficult. Immunohistochemical staining of 17 ECSCSs, 14 Sertoli cell tumors or SLCTs, and 15 AGCTs was performed with the use of antibodies against cytokeratins (AE1/AE3, 902, and CAM 5.2), epithelial tumor-associated antigens (EMA, OM-1, B72.3, and carcinoembryonic antigen B1.1), vimentin, S-100, neuron-specific enolase, and lysozyme to determine the immunohistochemical profile of each tumor type and to define further the nature of the sex cord-like components in ECSCSs. All 17 ECSCSs, none of the 15 AGCTs, and one of 14 Sertoli cell tumors or SLCTs stained with EMA. Staining for OM-1 was almost as helpful diagnostically, with positive results for 15 of 17 ECSCSs, 0/15 AGCTs, and 1/14 Sertoli cell or SLCTs. Antikeratins were immunoreactive with all the ECSCSs as well as some of the AGCTs and Sertoli cell tumors or SLCTs. The B72.3 and B1.1 were immunoreactive with some ECSCSs and Sertoli cell tumors, but were nonreactive with AGCTs. Neuron-specific enolase was demonstrated in 11 of 17 ECSCSs, two of 14 Sertoli cell tumors or SLCTs, and 0 of 15 AGCTs. Vimentin, S-100, and lysozyme were least helpful in the differential diagnosis. These studies suggest that an immunohistochemical approach may be useful in the differentiation of ECSCSs and sex cord-stromal tumors. Furthermore, it supports the conclusion that the sex cord-like cells in ECSCSs are not Sertoli or granulosa cells, but cells of surface epithelial type growing in architectural patterns similar to those of sex cord-stromal tumors.
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PMID:Ovarian endometrioid carcinomas resembling sex cord-stromal tumors. An immunohistochemical study. 247 93

Two hepatocellular carcinomas and six hepatoblastomas were examined for the presence of 13 antigens using immunoperoxidase, avidin-biotin, staining techniques. Primary antibodies were directed against alpha-fetoprotein (AFP), alpha-1-antitrypsin (AAT), lysozyme (LYS), carcinoembryonic antigen (CEA), human chorionic gonadotropin (HCG), glial fibrillary acidic protein (GFAP), neuron specific enolase (NSE), epithelial membrane antigen (EMA), hepatitis B surface antigen (HbSA), lactoferrin (LF), desmin (DES), vimentin (VIM), and keratin (KER). Except for HbSA, the antigen staining pattern was unable to differentiate between hepatoblastoma and hepatocellular carcinoma. Both neoplasms where positive for AFP, AAT, CEA, EMA, and KER; however, neither stained for GFAP, NSE, LYS, LF, HCG, or DES. Vimentin was weakly positive in those hepatoblastomas where mesenchymal tissue was present in the tumor. Only the tissue adjacent to hepatocellular carcinomas stained positively for HbSA and correlated with the elevated serum levels of HbSA.
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PMID:Patterns of antigen expression in hepatoblastoma and hepatocellular carcinoma in childhood. 248 9

Four sub-lines (strain A, C, D, E) were isolated from a human lung giant cell carcinoma cell line (PLA-801) by the single cell cloning technique. The incidence of spontaneous metastasis was higher in strain D, moderate in strains A, E and lower in strain C after they were inoculated subcutaneously into the nude mice. The lung and lymph-nodes were the major target organs of metastasis. Morphological studies (light microscope, electron microscope and immunohistochemistry) showed that the cytoplasm of metastatic tumor cells was rich in microfilament and positive for Vimentin. The results strongly support the theory on tumor cell heterogenicity. In addition, these clones, especially strains D and C, could be an ideal model for the study of tumor metastasis.
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PMID:[Spontaneous metastasis of clonal cell subpopulations of human lung giant cell carcinoma after subcutaneous inoculation in nude mice]. 255 Jan 96

Primary tumor of the aorta is extremely rare. An instance of aortic intimal sarcoma, namely fibromyxosarcoma, which extended from the beginning of the descending aorta to 7 cm above the abdominal bifurcation, with clinical evidence of acutely occurring hypertension, arterial embolism of the lower extremities, renal infarction, and aortic occlusion in a 50-year-old male is reported. The tumor was limited to the intima and composed of spindle-shaped tumor cells with abundant myxoid extracellular matrices. The tumor cells were negative for Factor VIII, Desmin, or Myoglobin, but were positive for Vimentin or Factor XIIIa in immunoperoxidase studies. An electron microscopic examination revealed a large amount of rough endoplasmic reticulum in the cytoplasm. Parenchymal metastases were observed in both the lungs and thoracic vertebrae. A review of literature on the clinical and pathological aspects of the tumor was made.
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PMID:A case of aortic intimal sarcoma manifested with acutely occurring hypertension and aortic occlusion. 258 79


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