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

A 46-year-old man underwent excision of a left lower eyelid mass that had enlarged over a 2-month period. Pathologic examination showed the mass to be an eccrine acrospiroma, a benign adnexal tumor that rarely arises in the eyelid. Light microscopic and ultrastructural examination showed two types of cells to comprise the tumor: eosinophilic cells with intracytoplasmic tonofilaments, and clear cells with intracytoplasmic glycogen granules. Immunohistochemical stains were positive for cytokeratins AE 1,3, epithelial membrane antigen, carcinoembryonic antigen, and muscle specific actin in tumor cells.
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PMID:Eccrine acrospiroma (clear cell hidradenoma) of the eyelid. Immunohistochemical and ultrastructural features. 170 58

The application of immunohistochemical markers against epithelial antigens has proved useful for studying tumor differentiation and in aiding tumor diagnosis. However, the reactivity of various epithelial markers with poorly differentiated carcinomas (the situation in which they are most often used) has not been well established. As a result, it is unclear how negative results should be interpreted and how often more than one antibody may be needed to document the epithelial nature of poorly differentiated neoplasms. We studied 98 poorly differentiated epithelial tumors with AE1, CAM 5.2, and EMA to assess the use of these markers in their diagnosis. Both CAM 5.2 and EMA provided support for epithelial differentiation in 71% (70/98) of the cases, while AE1 stained 50% (49/98) of the tumors; CAM 5.2 was the single most useful marker in the subset of poorly differentiated neuroendocrine carcinomas, staining 20 (77%) of 26 tumors. Use of these markers in pairs increased the recognition of epithelial differentiation (at least one marker showing positive staining) as follows: AE1/CAM 5.2, 80% (78/98); AE1/EMA, 87% (85/98); and CAM 5.2/EMA, 99% (97/98). Thirty carcinomas stained with all three markers, 34 with two markers, and in 34 cases only one antibody supported epithelial differentiation. Twelve (21%) of 58 tumors showed evidence of S100 reactivity. None of the 71 cases to which PD7 was applied showed staining This study indicates that poorly differentiated carcinomas are heterogeneous in their expression of antigens recognized by AE1, CAM 5.2, and EMA. Moreover, these results quantitate the probability of reactivity with poorly differentiated carcinomas for each marker and support the use of one or more antibodies in a "backup" panel when a negative result is obtained with a single antibody and the diagnosis of carcinoma is still suspected.
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PMID:Heterogeneity of epithelial marker expression in routinely processed, poorly differentiated carcinomas. 171 Jan

Three commonly used keratin monoclonal antibodies (MAB)--AE1:AE3, CAM 5.2, and MAK-6--were compared with routinely used cytokeratin antibody. The expression of these antibodies was analyzed in several tissues obtained from clinically normal dogs and in a variety of neoplasms from dogs. Using appropriate enzymatic digestion, paraffin-embedded tissues processed in routine manner retained their typical keratin expression. Differentiated and poorly differentiated epithelial neoplasms, lymphomas, and melanomas were studied by use of the avidin-biotin-peroxidase technique. All 4 of the aforementioned antibodies had similar staining profiles. Of 3 anaplastic carcinomas, 2 had positive reaction to all 4 antibodies. All lymphomas, plasma cell tumors, and amelanotic melanomas had negative reaction to MAK-6, CAM 5.2, AE1:AE3, and cytokeratin MAB. Three basal cell epitheliomas had positive reaction to all 4 antibodies, whereas 1 basal cell tumor with a solid pattern had negative staining reaction. Two carcinoids had negative reaction to all markers and 1 of 2 malignant chemodectomas and 1 transitional cell carcinoma had staining reaction to only AE1:AE3 MAB. Comparing the 4 antibodies, use of AE1:AE3 MAB produced the strongest staining intensity followed by cytokeratin, MAK-6, and CAM 5.2 MAB. All 4 antibodies had low background staining. In conclusion, AE1:AE3 and MAK-6 MAB are as useful as cytokeratin MAB for identification of poorly differentiated epithelial neoplasms in dogs and cats.
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PMID:Immunocytochemical study of tissues from clinically normal dogs and of neoplasms, using keratin monoclonal antibodies. 171 Dec 98

A 57-year-old man with malaise, ascites, and abdominal pain was found to have a peritoneum studied with numerous, small nodular tumor masses. Light microscopy revealed an anaplastic malignant tumor of uncertain differentiation. Mucin stains were negative. Electron microscopy revealed pleomorphic tumor cells with diffusely distributed cytoplasmic tonofilaments and well-developed true desmosomes. No long, thin, branching microvilli were present, yet tumor cells were strongly positive for both callus keratin (polyclonal) and monoclonal cytokeratin (AE1/3) in a diffuse cytoplasmic distribution (a pattern corresponding to the diffuse cytoplasmic tonofilaments). Tumor cells were negative for Leu-M1 and carcinoembryonic antigen. The findings were most consistent with malignant mesothelioma, and additional questioning, after tissue diagnosis, revealed a work history of asbestos exposure.
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PMID:Malignant mesothelioma of peritoneum. 172 49

The expression of AE1, AE2, AE3, and CAM 5.2 antikeratin monoclonal antibodies was investigated in 68 vulvar specimens by an avidin-biotin complex (ABC) method. They included normal vulva (NV, 10), non-neoplastic epithelial disorders (NNED, 31), vulvar intraepithelial neoplasia (VIN, 17), and squamous cell carcinoma (SCC, 10). AE1 weakly stained the basal cell layer in NV, exhibited a uniform suprabasal stain in hyperplasia, failed to stain dysplastic areas in VIN I-II, and was patchy and disorganized in VIN III and SCC. AE2 stained the upper third of the epithelium in NV, NNED, and VIN I-II, but it failed to stain VIN III basaloid and SCC; VIN III bowenoid was focally positive. AE3 offered little information, because it stained all lesions; VIN III and SCC, however, exhibited a patchy and disorganized stain. CAM 5.2 was expressed in only half of the cases of VIN III basaloid and in one case each of VIN I-II and SCC. We conclude that keratin expression varies according to the degree of dysplasia; AE1 may serve to separate certain cases of NNED from VIN I-II; AE2 and CAM 5.2 are useful to differentiate both histologic types of VIN III.
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PMID:Keratin expression in normal vulva, non-neoplastic epithelial disorders, vulvar intraepithelial neoplasia, and invasive squamous cell carcinoma. 172 57

Eleven primitive neuroectodermal tumor (PNET) biopsies from infants under the age of 3 years were studied for the presence of various differentiation markers for neuroectodermal stem cells. Special emphasis was placed on the expression of cytokeratin proteins. The tumor cells expressed different cytokeratin proteins (CK8, CK13, CK18, CK19, KL1, AE1/AE3, MNF16) in 3 of 11 cases. These cases were furthermore characterized by a strong expression of glial fibrillary acidic protein, S-100 protein and vimentin. Vimentin and cytokeratin proteins were co-expressed; cross-reactivity between these two intermediate filaments could be excluded by immunoblotting. It is noteworthy that the three positive tumors were all from infants in their 1st year. We assume that PNETs in early infancy are characterized by a particularly wide range of differentiation patterns. The presence of cytokeratin proteins in these cases seems to be associated with the expression of vimentin and must be regarded as an indicator of an early developmental stage of the tumor cells.
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PMID:Immunohistochemistry of primitive neuroectodermal tumors in infants with special emphasis on cytokeratin expression. 172 29

Immunohistochemical analysis of intermediate filament (IF) proteins was performed on frozen sections of 16 childhood glial tumors using a library of 10 antigen-specific IF protein directed monoclonal antibodies (MoABs) and a four-step biotin-streptavidin-alkaline phosphatase conjugated antigen detection immunocytochemical technique. Human glial fibrillary acidic protein (GFAP) and vimentin were expressed in all brain tumors. High molecular weight (200 kDa) neurofilament (NF-H) protein was expressed in 15 out of 16 tumors; medium molecular weight (160 kDa) neurofilament (NF-M) in seven out of 16 tumors; and low molecular weight (68 kDa) neurofilament (NF-L) in five out of 16. Positive acidic keratin reactivity was found in five out of 16 tumors using MoAB AE1. Expression of a keratin pair was detected with MoAB AE2 in five out of 16 tumors. A second keratin pair in 14 out of 16 glial tumors was demonstrated with MoAB AE3. Immunostaining with AE5 defined the expression of another basic keratin (64 kDa) in nine out of 16 glial tumors. Finally, in 14 out of 16 astrocytomas an individual 51 kDa acidic keratin (detected with MoAB AE8) was expressed. Glial tumor cells contain cell lineage specific and nonspecific IF proteins in the following IF pattern: AE3+, AE8+, GFAP+, vimentin+, and NF-H+. The heterogenous composition of these cytoskeletal IF proteins in childhood glial tumors may reflect a direct stage dependent correlation with their neoplastic transformation.
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PMID:Co-expression of four intermediate filament subclasses in childhood glial neoplasms. 172 88

A 66-year-old woman presented with a superior-anterior mediastinal mass that contained considerable calcification by computed tomography. Initial biopsy interpretation was inconclusive but suggested a giant cell sarcoma of soft parts because the tumor contained atypical epithelioid cells and osteoclastlike giant cells. After radiation and chemotherapy, the tumor was removed. It contained large epithelioid cells, pale chondroid areas, metaplastic bone, and osteoclastlike giant cells. Immunohistochemical and electron microscopic studies revealed the epithelioid cells to be factor VIII positive and to contain abundant intermediate filaments, micropinocytotic vesicles, Weibel-Palade bodies, basal lamina, and primitive cell-cell junctions. These epithelioid cells also stained for muscle-specific actin (HHF-35), yet were negative for desmin and cytokeratins (CAM 5.2 and AE1/3). The findings were most consistent with those reported to occur in epithelioid hemangioendothelioma.
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PMID:Atypical tumor of the mediastinum: epithelioid hemangioendothelioma containing metaplastic bone and osteoclastlike giant cells. 175 5

To study coexpression patterns in normal and adenomatous pituitaries, frozen (n = 4) and paraffin-embedded (n = 10), normal human glands and 34 pituitary adenomas were investigated, using immunoperoxidase and double-labeling immunofluorescence methods. Broad range monoclonal antibodies (mAB) against cytokeratins (CK) (lu-5, A45-B/B3, AE1/3, CAM 5.2) as well as anti-CK18 (DC10) and anti CK19 (A53-B/A2) were compared with mAB's against vimentin, epithelial membrane antigen (EMA), epithelial sialomucin (ESM 140 C1), GFAP (GF-2), neurofilament (2F11), Leu-7 (HNK-1) and polyclonal AB's against pituitary hormones (ACTH, FSH, LH, TSH, GH, PRL). CK and vimentin coexpressing endocrine cells, mainly of the ACTH type, were observed in the pars intermedia in 5 of 14 normal pituitaries. All hormone producing cells expressed CK. The mAB A53-B/A2 (CK19) stained selectively the folliculo-stellate cells in frozen and paraffin sections. EMA, sialomucin and Leu-7 antigen localized to different structures of normal pituitaries. 25 of 34 pituitary adenomas exhibited CK positive tumor cells. Coexpression of vimentin or neurofilament protein was rare (2 cases of each). 9 CK negative adenomas were also negative for other intermediate filament proteins. 6 hormone producing adenomas showed unusual positivity for CK19. Whereas EMA and sialomucin reactivity disappeared in adenoma tissues, an enhanced Leu-7 antigen expression in the GH and prolactin adenoma group was noted. The heterogeneity of antigen expression seen in normal and neoplastic pituitary cells calls for further functional studies and usage of a broad range of mAB's against intermediate filaments in immunohistochemical studies of the pituitary.
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PMID:Immunohistochemical studies on human pituitary gland and adenomas. 182 19

The article describes a case of gastrointestinal autonomic nerve tumor, which is histogenetically related to the gastrointestinal autonomic plexus (hence the name plexosarcoma). This rare and only recently recognized tumor of the gastrointestinal tract appears to have significant prognostic implications. This tumor cannot be diagnosed unequivocally by light microscopic and immunocytochemical examinations but shows characteristic electron microscopic features. The present case occurred as a gastric primary tumor and exhibited a light and electron microscopic picture similar to the one described in previous reports: areas of spindle-shaped and epithelioid cells, cytoplasmic processes with dense-core granules, and cytoplasmic intermediate filaments. Ultrastructural characteristics diagnostic of other gastrointestinal tumors, such as those originating from smooth muscle, Schwann cell, or endocrine cell types, were absent. Immunocytochemically, the tumor was diffusely positive for vimentin and neuron-specific enolase and focally positive for neurofilament triplet protein (NFTP) 160. Negative staining was observed for NFTP 200, S-100 protein, desmin, somatostatin, chromogranin, keratins (AE1/AE3), and glial fibrillary acidic protein. Although gastrointestinal autonomic nerve tumor has been reported to have a deceptively low-grade malignant appearance by light microscopy, it follows an aggressive clinical course. This tumor showed a much higher mitotic rate (one mitosis per high-power field) than the rates of tumors reported previously. Moreover, it occurred in a much younger patient (20 years of age) compared to previously reported cases (45 to 66 years of age), with the exception of one other case (16 years of age).
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PMID:Gastrointestinal autonomic nerve tumor. 184 28


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