Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0027651 (tumor)
 685,946 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Epithelioid hemangioendothelioma is a recently described vascular neoplasm characterized by epithelioid tumor cells and borderline biologic behavior. Its four principal sites of occurrence are the soft tissue, liver, lung, and bone. We report a case of primary cerebral epithelioid hemangioendothelioma in a 4-month-old male infant. The tumor consisted of loose aggregates of epithelioid cells with a focal cordlike or bridging-branching pattern, supported in a fibromyxoid stroma. The tumor cells displayed frequent intracytoplasmic vacuoles. Immunohistochemically, the tumor cells showed positive staining for Ulex europaeus agglutinin, vimentin, and cytokeratin. The tumor pursued an indolent clinical course. The patient was alive 28 months after initial presentation, but he was left with a severe neurological deficit because of the location and growth of the tumor.
 ...
PMID:Epithelioid hemangioendothelioma of the brain. 137 23

Mucoepidermoid carcinomas of the salivary gland comprising low (n = 6), intermediate (n = 11) and high grade malignant (n = 11) tumors were evaluated for immunohistochemical reactivity of cytokeratin (monoclonal antibody KL1, PKK1, K8.12), vimentin, involucrin and secretory proteins (lysozyme, LY; lactoferrin, LA; alpha 1-antitrypsin, alpha 1-AT and alpha 1-antichymotrypsin, alpha 1-Ach). Keratin expression was usually confined to intense staining in epidermoid tumor cells, but was negative in almost all mucous cells. Vimentin was coexpressed with keratin only in epidermoid tumor cells. Great heterogeneity of intermediate filament proteins was found in intermediate and epidermoid tumor cells. Involucrin in epidermoid tumor cells was particularly abundant in well keratinized cells but was lacking in intermediate and mucous forming cells. The frequency of occurrence of positive staining for LY, LA, alpha 1-AT and alpha 1-Ach was relatively low in mucoepidermoid carcinoma with positive immunohistochemical staining for these secretory proteins in mucous forming tumor cells, while varying expression was observed in epidermoid tumor cells.
 ...
PMID:Mucoepidermoid carcinoma of the salivary glands: immunohistochemical distribution of intermediate filament proteins, involucrin and secretory proteins. 137 95

Thymomas are cytologically benign epithelial neoplasms of the thymus gland. They compose 10% of mediastinal tumors, and are most common in the anterosuperior compartment. Seven to 36% of thymomas are malignant, as determined by tissue invasion, yet they metastasize in less than 3% of cases. Distinguishing lymphoma from lymphocyte-predominant thymoma is imprecise due to their histologic similarities. We present a 45-year-old man with intracranial metastatic thymoma. The lesion was interpreted radiographically as meningioma, and as possible lymphoma by frozen section. Flow cytometry proved this neoplasma to be a metastatic thymoma. Sixteen monoclonal antibodies were used to immunophenotype the CD45+ component of this tumor. Coexpression of CD4 and CD8 along with CD1 demonstrated lymphocytes of late cortical thymocyte origin; a second component was cytokeratin positive. This is the first reported case of extrathoracic metastases of thymoma diagnosed using flow cytometry. We propose this method as an invaluable technique to diagnose these histologically difficult neoplasms.
 ...
PMID:Diagnosis of metastatic thymoma using flow cytometry. 137 81

We have established a cell line (KU-SN) from a peripheral neuroectodermal tumor originating in the left scapula of a 4-year-old girl. The original tumor was immunoreactive with antibodies for neurofilament proteins, neuron-specific enolase, vimentin, S100 protein, and beta 2-microglobulin. Dense core granules, 50-150 nm in diameter, were identified by electron microscopy. The cell line was established from tumor cells in metastatic lung fluid. KU-SN cells were immunoreactive with the antibodies for neurofilament proteins, vimentin, neuron-specific enolase, S100 protein, glial fibrillary acidic protein, cytokeratin, and carcinoembryonic antigen. Besides these neuronal features, KU-SN cells express type 2 collagen and insulin-like growth factor 1 receptor. The addition of insulin-like growth factor 1 (100 ng/ml) increased the growth rate of KU-SN cells 2.1-fold over control. Some cells were positive for Alcian blue and alkaline phosphatase staining. Cytogenetic analysis of KU-SN cells disclosed a reciprocal chromosomal translocation [t(11,22)]. Northern blot analysis of KU-SN cells demonstrated amplified expression of the c-myc gene but not the N-myc gene. When tumor cells were transplanted into nude mice, cartilage was formed. The cartilage was immunoreactive with the antibody for HLA-ABC, indicating that it was derived from the tumor cells, not from mouse tissue. Chondrocytic differentiation was not observed in xenografts of Ewing's sarcoma cell lines SK-ES or RD-ES or the peripheral neuroectodermal tumor cell line SK-N-MC. These results indicate that KU-SN cells represent primitive neural crest cells having the potential for chondrocytic differentiation.
 ...
PMID:Chondrocytic differentiation of peripheral neuroectodermal tumor cell line in nude mouse xenograft. 137 22

The importance of cervical squamous metaplasia and human papillomavirus 16 (HPV 16) infection for cervical carcinoma has been well established. Nearly 87% of the intraepithelial neoplasia of the cervix occur in the transformation zone, which is composed of squamous metaplastic cells with unclear origin. HPV DNA, mostly HPV 16, has been found in 90% of cervical carcinomas, but only limited experimental data are available to discern the role of HPV 16 in this tissue specific oncogenesis. We have initiated in vivo studies of cultured endocervical cells as an experimental model system for development of cervical neoplasia. Using a modified in vivo implantation system, cultured normal endocervical epithelial cells formed epithelium resembling squamous metaplasia, whereas those immortalized by HPV 16 developed into lesions resembling carcinoma in situ. In contrast, their ectocervical counterparts formed well differentiated stratified squamous epithelium and a lesion with mild dysplastic change, respectively. The HPV 16-immortalized cells showed in vivo cytokeratin expression patterns similar to their respective normal counterparts, confirming their different origins. Thus, this study provides direct experimental evidence for the transformation of simple epithelial cells of endocervical origin into stratified squamous metaplasia and indicates the differential susceptibility of endo- and ectocervical epithelial cells for conversion to cancer by HPV 16.
 ...
PMID:Squamous metaplasia of normal and carcinoma in situ of HPV 16-immortalized human endocervical cells. 137 23

The constituent cells in malignant peripheral nerve sheath tumors were examined by studying the expression of immunohistochemical markers for Schwann cells and perineurial cells in relation to ultrastructural features in 12 malignant peripheral nerve sheath tumors. Ultrastructural studies demonstrated mixed proliferation of Schwann cells, perineurial cells, fibroblastic cells, and primitive cells in many malignant peripheral nerve sheath tumors. Expression of S-100 protein was well correlated with Schwann cell-like differentiation of tumor cells. However, Leu-7 and epithelial membrane antigen, which have been considered to be specific to Schwann cells and perineurial cells, respectively, were common to Schwann cells, perineurial cells, and primitive cells. The common immunophenotypic expression suggests a close relationship among these cell types. The unusual expression of cytokeratin could be explained by the plasticity of intermediate filament expression.
 ...
PMID:Malignant peripheral nerve sheath tumors: an immunohistochemical study in relation to ultrastructural features. 137 71

The ability of a panel of monoclonal antibodies generated in this laboratory to identify "pagetoid" melanoma cells and distinguish them from true Paget's adenocarcinoma cells in a retrospective analysis of vulvar neoplasms was investigated. Paraffin blocks of formalin and Carnoy's fixed tissue from 15 cases of vulvar Paget's disease and 11 cases of primary vulvar melanoma were retrieved and sections were incubated with the following panel of monoclonal antibodies: HMB45, a melanoma-specific monoclonal antibody; and 35 beta H11 and 34 beta E12, two different anti-cytokeratin monoclonal antibodies, to low molecular and high molecular weight cytokeratins, respectively. The anti-melanoma monoclonal antibody (HMB45) positively identified the melanoma cells, distinguishing them from normal melanocytes, in all 11 cases of melanoma. In contrast, the HMB45 antibody failed to react with the intraepithelial neoplastic cells in all cases of Paget's disease. These latter malignant cells were strongly positive only with the monoclonal anti-low molecular weight cytokeratin antibody 35 beta H11. This latter antibody absolutely distinguished tumor cells from neighboring uninvolved squamous epithelium, which was positive only with the monoclonal antibody 34 beta E12. Using this panel of monoclonal antibodies, the surgical margins could also be better evaluated; in at least one case the surgical margin thought by histological evaluation to be free of tumor was demonstrated by immunocytochemistry to be positive for tumor. In the vulvectomy specimens obtained in both diseases, Paget's or melanoma cells were identified in sections histologically interpreted as free of tumor. Thus, a panel of monoclonal antibodies is able to identify, with high sensitivity and specificity, vulvar melanoma cells and absolutely distinguish them from vulvar Paget's cells and can help in evaluating surgical margins in a more accurate manner.
 ...
PMID:Paget's disease and melanoma of the vulva. Use of a panel of monoclonal antibodies to identify cell type and to microscopically define adequacy of surgical margins. 137 62

Seven hepatoblastomas were studied by electron microscopy, and four of these were studied by immunohistochemistry. Five tumors were purely epithelial, and two were mixed epithelial-mesenchymal. They showed a spectrum of cellular differentiation ranging from primitive epithelial cells to differentiated cells resembling adult hepatocytes. Glycogen, lipid, basal lamina, and canaliculi were present in all cases. Mitochondria with large, membrane-bound, amorphous inclusions were present in one tumor, and large, complex, basal cell processes were present in two tumors. Ultrastructural features most characteristic of hepatocytes were most common in fetal type hepatoblastomas. Immunoreactive chromogranin cells were present in two tumors, one of which also contained immunoreactive somatostatin cells. The somatostatin-positive tumor had cells with granules resembling those seen in somatostatin-containing cells of normal pancreas and somatostatin-containing neuroendocrine carcinomas. Other immunoreactive substances were present, including alpha 1-antitrypsin (four cases), vimentin (embryonal cells in four cases; fetal cells in three cases), low-molecular weight cytokeratin (embryonal cells in three cases; fetal cells in four cases), and high-molecular weight cytokeratin (embryonal cells in one case; fetal cells in two cases). Osteoidlike material was positive for epithelial membrane antigen, vimentin, and S-100 protein.
 ...
PMID:Hepatoblastomas: an ultrastructural and immunohistochemical study. 138 Jan 93

This case report details an osteogenic sarcoma arising in a vertebra in which cytokeratin intermediate filaments were detected immunohistochemically with three different antibodies. This feature was present not only in the primary neoplasm but also in two local recurrences and a metastasis to the iliac bone. What is unique about this primary bone tumor, however, is the structural evidence for epithelial differentiation. Ultrastructurally, well-formed desmosomes and tonofilaments were present in all four surgically resected specimens. This tumor expands the list of soft tissue and bone tumors in which anomalous expression of intermediate filaments can occur but, more important, illustrates that changes in genetic expression of neoplasia of mesenchymal origin can result in paradoxic epithelial differentiation.
 ...
PMID:Osteogenic sarcoma with epithelial differentiation. 138 Jan 94

The histologic distinction between nodular hidradenoma and glomus tumor is an occasional difficult diagnostic problem. Both tumors may show circumscribed aggregates of uniform epithelioid cells, a myxoid stroma, and variable numbers of blood vessels. Especially troublesome are solid cellular hidradenomas without duct-like structures and glomus tumors without a vascular pattern. To develop an immunohistochemical profile useful in this differential diagnosis, 25 selected skin tumors and four normal glomus bodies were studied with antibodies against low molecular-weight cytokeratin (CAM 5.2), epithelial membrane antigen (EMA), carcino-embryonic antigen (CEA), S-100, and vimentin (VIM). The tumors included eight unequivocal hidradenomas, seven unequivocal glomus tumors, and 10 histologically equivocal cases, originally diagnosed as glomus tumors. In all unequivocal glomus tumors and glomus bodies, only VIM was positive. Of the eight unequivocal hidradenomas, three were positive for CAM 5.2, EMA, CEA, S-100, and VIM; two for CAM 5.2 only; one for CAM 5.2, EMA, and S-100; one for CAM 5.2, EMA, and CEA; and one for CEA only. In the histologically equivocal cases, eight were positive for VIM only, characteristic of glomus tumor; and two were positive for CAM 5.2, EMA, CEA, S-100, and VIM, and were reclassified as hidradenomas. The study suggests that morphologic criteria may not always accurately differentiate between hidradenoma and glomus tumor and that in equivocal cases immunohistochemistry may be useful in the differential diagnosis.
 ...
PMID:Immunohistochemistry in the differential diagnosis of nodular hidradenoma and glomus tumor. 138 Feb 7


<< Previous 1 2 3 4 5 6 7 8 9 10 Next >>