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

Thirteen cases of primary thymic carcinomas are described. The patients' ages ranged from 19 to 64 years, with a median of 40 years. Nine of them were male. Chest pain with or without cough was the main presenting symptom. No patient had myasthenia gravis. Five histological types were identified; two were undifferentiated (lymphoepithelioma-like) carcinoma, one was a clear-cell carcinoma, two were mixed squamous and small-cell carcinoma, and six were squamous cell carcinoma. All the tumors were variably positive for anti-keratin antibody AE1 and AE3, but negative for AE2. Anti-neuron specific enolase antibody was useful in identifying and confirming the small-cell carcinoma component of the mixed carcinomas. Anti-epithelial membrane antigen antibody aided in revealing the glandular structures in mixed adenosquamous and small-cell carcinomas. Thymic carcinomas were histopathologically differentiated from thymomas by their malignant cytological appearance, increased mitotic activity, and central tumor necrosis. All six patients with pure squamous-cell carcinoma were still alive, with a median survival time of 27 months. All but one of the other patients of different histological types died, the exception being a recent case of mixed adenosquamous and small-cell carcinoma; their median survival was 19.5 months, or 18 months when the latter surviving case is included. The prognosis of patients with pure squamous-cell carcinoma was better.
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PMID:Thymic carcinomas: histopathological varieties and immunohistochemical study. 229 78

Immunohistochemical (IHC) techniques should allow for a greater detection of bone marrow micrometastasis in patients with breast carcinoma. We studied a series of bone marrow (BM) biopsies negative by conventional histologic techniques from 93 patients with breast carcinoma. Prior to this study, twelve BM biopsies, positive by conventional histology, were stained with a panel of monoclonal antibodies (MoAb), directed either against cytokeratin (KL1, AE1-AE3, CAM5-2) or epithelial membrane antigen (EMA, HMFG2). KL1 appeared to be the most sensitive of the markers used in the detection of metastases and is available commercially. It therefore was the only MoAb used with the series of 93 BM biopsies negative by conventional examination. Within this series, among 45 patients clinically suspected of having bone marrow metastasis but with BM biopsies negative by conventional staining, one case showing myelofibrosis stained positive with KL1 demonstrating isolated tumor cells. For the 48 patients without suspicion of bone marrow metastasis at initial diagnosis for breast carcinoma, KL1 revealed no marrow metastasis. Single bone marrow biopsy techniques whether stained by conventional or IHC methods do not appear to be useful tests to detect occult bone marrow metastasis, especially at initial diagnosis of clinically Mo breast carcinoma patients.
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PMID:Immunohistochemical staining of bone marrow biopsies for detection of occult metastasis in breast cancer. 232 27

A large number of human neoplasms were tested for their keratin expression in routinely processed tissues by a simple, three-stage immunoperoxidase method using a broadly reactive monoclonal anti-keratin antibody AE1, which recognizes a number of keratin polypeptides distributed in a wide variety of epithelia. All carcinomas, with the exception of hepatocellular, adrenocortical, and basal cell carcinomas and occasional renal cell, pulmonary small-cell, and pulmonary large-cell anaplastic carcinomas, reacted with this antibody irrespective of differentiation, in most instances displaying staining of strong or moderate intensity in the majority of tumor cells. Equivocal results were obtained in some seminomas and dysgerminomas. Malignant melanoma, large-cell lymphoma, Hodgkin's disease, malignant histiocytosis, and stromal mesenchymal elements in all tumors did not show any reactivity with AE1. Even after routine processing, the determinant detected by AE1 is conserved and restricted to epithelial neoplasms. This suggests that AE1 would be valuable in the diagnostic distinction of anaplastic carcinoma from lymphoma and melanoma in routinely processed tissues.
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PMID:Monoclonal anti-keratin (AE1) reactivity in routinely processed tissue from 166 human neoplasms. 241 15

Three monoclonal anti-keratin antibodies, AE1, AE3, and AE4, were used to compare the expression of keratins in normal, preneoplastic, and malignant mouse mammary epithelial cells growing in primary culture. In indirect immunofluorescence, AE1 did not stain normal cells but did stain a minority of preneoplastic and carcinoma cells. AE3 reacted with a subpopulation of epithelial cells in both the normal and abnormal cultures, except for certain cultures from one type of tumor wherein all of the epithelial cells were reactive. AE4 decorated an elaborate keratin filament network in all cultured mammary epithelial cells, regardless of neoplastic state. In double-label immunofluorescence, a guinea pig anti-keratin antiserum, which reacts preferentially with myoepithelial cells, exhibited coincident staining with AE1 in the tumor cultures and AE3 in the normal and most tumor cultures, indicating that the cells recognized by the antibodies in these populations were myoepithelial. Immunoblot experiments with cytoskeletal polypeptides extracted from the normal and tumor cells demonstrated that the set of keratins recognized by each monoclonal antibody was essentially the same in all of the cells except for a Mr 40,000 component that was present in normal cells but either absent or diminished in the cancer cells. Thus, while normal cells had Mr 40,000 and 50,000 keratins recognized by AE1, the epitope detected by this antibody was apparently concealed or "masked" in situ. AE3 reacted in immunoblots with a major keratin group (Mr 54,000-55,000) and a minor keratin (Mr 57,000), while AE4 reacted only with the Mr 54,000-55,000 keratin species. Because immunofluorescence with AE4 showed that the Mr 54,000-55,000 keratin group was present in all mammary epithelial cells, the AE3-reactive epitope must be masked in the majority of normal and tumor cells. The data therefore showed that epitopes on three major keratins, the Mr 40,000, 50,000, and 54,000-55,000 group, were "masked" in normal cells, whereas in tumor cells "masking" involved primarily the Mr 54,000-55,000 keratin. Attempts to "unmask" the epitopes recognized by AE1 in normal cells or to increase the number of cells reactive with AE3 in the normal and tumor cultures failed. Thus, certain cultured preneoplastic and neoplastic mammary cells with a myoepithelial phenotype have an altered organization of keratins that is manifested by a keratin antigenic determinant which is visible by immunocytochemistry in the abnormal cells but not in normal mouse mammary cells. This is the first demonstration that the immunoreactivity of keratins can be modified during neoplastic progression of epithelial cells.
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PMID:A keratin epitope that is exposed in a subpopulation of preneoplastic and neoplastic mouse mammary epithelial cells but not in normal cells. 241 2

Epithelial membrane antigen and keratin proteins represent markers of epithelial differentiation that may be detected in routine formalin-fixed, paraffin-embedded tissues. Eighty-seven neoplasms, including 48 adenocarcinomas of various types, squamous and transitional cell carcinomas, small-cell anaplastic carcinomas, carcinoid tumors, mesotheliomas, hepatomas, melanomas (metastatic), adrenal cortical carcinomas, germ cell tumors, and extramammary Paget's disease, were assessed to determine the relative effectiveness of these antigens as tumor markers. Immunoperoxidase studies were performed using monoclonal antibodies to epithelial membrane antigen and monoclonal (combined AE1 and AE3) and polyclonal (bovine muzzle keratins) antibodies to keratin proteins. In more than half the cases (50/87%), both markers yielded comparable results. However, in 29 cases (33%), keratin proteins were clearly superior to epithelial membrane antigen as a tumor cell marker. Particular discrepancies were apparent for some gastrointestinal adenocarcinomas, squamous cell carcinomas, hepatomas (hepatocellular type), spindle cell components of mesotheliomas, and carcinoid tumors. Epithelial membrane antigen represented a better marker in eight cases (9%), mainly for small-cell anaplastic carcinomas and some renal cell and pulmonary adenocarcinomas. Adrenal cortical carcinomas, melanomas, and seminomas were nonimmunoreactive for both antigens. Epithelial membrane antigen and keratin proteins represent useful complementary markers in diagnostic surgical pathology.
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PMID:Are keratin proteins a better tumor marker than epithelial membrane antigen? A comparative immunohistochemical study of various paraffin-embedded neoplasms using monoclonal and polyclonal antibodies. 242 37

The histogenetic origin of the spindle-cell component of spindle-cell carcinoma of the head and neck mucosa remains controversial. The spindle cells have been considered a variant growth pattern of squamous-cell carcinoma, a non-neoplastic mesenchymal reaction, and a malignant admixture of epithelial and mesenchymal neoplasm. To evaluate the spindle-cell component, we studied 25 tumors (18 biphasic and seven monophasic) by utilizing the following: an avidin-biotin complex immunoperoxidase technique with a variety of antikeratin antibodies (AE1, AE3, CAM 5.2, 35BH11, and polyclonal Dako) and a monoclonal antivimentin antibody, and an avidin-biotin alkaline phosphatase double-labeling technique to detect coexpression of keratin and vimentin. The immunohistologic staining pattern was compared with electron-microscopic studies. Eight of 18 biphasic neoplasms contained immunoreactive keratin in the spindle-cell component that was distributed focally in a minority of cells in 3 tumors and diffusely throughout five of the neoplasms. Four of seven ulcerated monophasic spindle-cell tumors devoid of histologic squamous-cell carcinoma also were keratin positive, confirming epithelial differentiation. The majority of the spindle cells in all the tumors contained vimentin intermediate filaments. In three immunoperoxidase keratin positive biphasic tumors examined with alkaline phosphatase double labeling, occasional spindle cells were found that coexpressed keratin and vimentin and were interspersed with cells expressing either intermediate filament. Electron microscopy was performed on the spindle-cell component of 13 tumors, nine biphasic and four monophasic. Of the biphasic tumors, four were immunoperoxidase keratin positive; three of these showed epithelial differentiation by electron microscopy. Five biphasic tumors were keratin negative, and three tumors had epithelial differentiation by electron microscopy. Four monophasic spindle-cell tumors were immunoperoxidase keratin positive, and one of these had epithelial features by electron microscopy. Two monophasic tumors were keratin negative and without ultrastructural evidence of epithelial features. By using a combination of immunohistochemical and electron-microscopic observations, we identified evidence for epithelial differentiation in the spindled cells in 11 of 18 biphasic tumors and four of seven monophasic spindle-cell tumors.
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PMID:Spindle-cell carcinoma of the upper aerodigestive tract mucosa. An immunohistologic and ultrastructural study of 18 biphasic tumors and comparison with seven monophasic spindle-cell tumors. 243 Apr 74

A vaginal squamous cell carcinoma was found to produce amyloid in the more differentiated portion of the tumor. The amyloid was identified by immunohistochemical technique as related to keratin proteins reactive with monoclonal antibodies AE1 and AE3 but not AE2.
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PMID:Amyloid in squamous cell carcinoma of the vagina: immunohistochemical study with monoclonal anti-keratin antibodies. 243 39

Among the monoclonal antibodies capable of detecting epithelial lineage, some recognize keratin and others identify antigens of epithelial membranes. Of the latter, the most commonly used is directed against an antigen present in cell membranes derived from milk fat globules, epithelial membrane antigen (EMA). To determine their relative sensitivity and specificity and hence their diagnostic value, we compared four commercially available monoclonal antibodies to low-molecular-weight keratins--AE1, CAM 5.2, PKK1, and 35 beta H11--with the monoclonal antibody to EMA (anti-EMA). We studied 383 samples of human neoplasms of diverse histogenetic types and degrees of differentiation. Anti-EMA was found to be less sensitive than the monoclonal antibodies to keratin in several epithelial tumors, including tumors of the prostate (11 of 13 negative), gastrointestinal tract (13 of 34 negative), and thymus (seven of eight negative). Anti-EMA was also less sensitive in mesotheliomas (nine of 24 negative). Of the embryonal carcinomas, all stained with the monoclonal antibodies to keratin, whereas none stained with anti-EMA. False-positive staining with anti-EMA was seen in two of 14 T-cell lymphomas. We conclude that the monoclonal antibodies to low-molecular-weight keratins are more sensitive and specific for the identification of epithelial origin of neoplasms than is monoclonal anti-EMA. Anti-EMA should not be used as the sole marker of epithelial differentiation in tumor diagnosis.
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PMID:Keratins versus epithelial membrane antigen in tumor diagnosis: an immunohistochemical comparison of five monoclonal antibodies. 243 36

Two monoclonal antikeratin antibodies, AE1 and AE3, were used in indirect immunocytochemistry to examine keratin expression in normal, benign proliferative, and malignant human breast epithelium. Both antibodies reacted strongly with most luminal cells in ducts and acini of normal gland. While AE1 did not stain myoepithelium, AE3 recognized myoepithelial cells of ducts but not acini, implying a cytoskeletal difference between the myoepithelium of these two components. Moreover, the antibodies reacted differently with the myoepithelium of intracanalicular as compared with pericanalicular types of fibroadenomas. Tumour cells of infiltrating ductal carcinomas with a prominent intraductal component stained more homogeneously with AE1 and AE3 than those without intraductal growth. The results provide evidence for two phenotypes of myoepithelial cells and for the presence of cryptic keratin epitopes in human breast epithelial cells. The finding that neither AE1 nor AE3 is a universal detector of these cells has important clinical and experimental implications.
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PMID:Structural distinctions among human breast epithelial cells revealed by the monclonal antikeratin antibodies AE1 and AE3. 244 54

A total of 32 hepatocellular carcinomas (HCC), 10 cholangiocarcinomas (CC), one combined HCC-CC, and 10 adenocarcinomas metastatic to the liver were studied immunohistochemically using AE1 and Cam 5.2, monoclonal antikeratin antibodies with different specificities. AE1 recognizes keratins with molecular weights of 56.5, 50/50', 48, and 40 kd (keratin nos. 10, 14, 15, 16, and 19, according to Moll's catalog), and labels many epithelia, including bile duct epithelium, but not hepatocytes. Both biliary epithelium and hepatocytes are stained by Cam 5.2, which reacts with keratins of molecular weights 50, 43, and 39 kd (corresponding to keratin nos. 8, 18, and 19). Tissues were formalin fixed, paraffin embedded, and a three-stage immunoperoxidase technique was employed. Of 32 pure HCCs, 29 were unreactive with AE1 yet were positive with Cam 5.2. The intensity and extent of immunostaining with Cam 5.2 did not correlate with tumor grade. In contrast to the HCCs, all 10 CCs and the 10 hepatic metastases were strongly positive with both AE1 and Cam 5.2. The combined HCC-CC was also labeled by both antibodies. We conclude that most HCCs express an immunohistochemical keratin profile identical to that of nonneoplastic hepatocytes, which differs from the keratin patterns of bile ducts, CCs, and metastatic adenocarcinomas from a variety of primary sites. These differences in immunoreactivity with antikeratin antibodies may prove useful in diagnostic surgical pathology.
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PMID:The diagnostic utility of the keratin profiles of hepatocellular carcinoma and cholangiocarcinoma. 244 24


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