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Query: UMLS:C0025202 (melanoma)
 69,561 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

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.
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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

The use of non-radioactive in situ hybridization (ISH) with chromosome-specific repetitive DNA probes to study genomic changes, aneuploidy, and heterogeneity during melanocytic tumor progression, relies on its applicability to non-mitotic interphase nuclei, present in cell suspensions and tissue sections. Therefore, we studied the feasibility of detecting numerical aberrations with respect to the (peri-) centromere regions of chromosomes 1 and 7 in intact nuclei of two human melanoma cell lines with different metastatic behavior in nude mice. In addition, we used paraffin sections from xenograft lesions, obtained by inoculation of these cell lines in nude mice (subcutaneous tumors and spontaneous lung metastases). Paraffin sections from the original primary cutaneous melanoma (with a subepidermal and a dermal part) and two loco-regional metastases were also studied, one of which was the source for the cell lines. These cells and tissues represent examples of materials used in different approaches to the study of melanocytic tumor progression. Regarding the targeted sequences, ISH analysis showed that both cell lines were heterogeneous and aneuploid. The results correlated well with those obtained by ISH on metaphase spreads. Differences between the lines, which could not be detected by flow-cytometric or conventional karyotyping analysis, included data suggestive of a polyploid subpopulation and an extra copy of chromosome 7 in the metastasizing cell line. The polyploid population could be detected also in the paraffin sections of the corresponding subcutaneous xenografts and lung metastases in the mice. Both areas in the patients' primary melanoma could be evaluated separately and showed similar supernumerary aberrations of the chromosome-specific targets. These abnormalities matched those found in both metastases. Our results demonstrate that ISH can be used to visualize genomic abnormalities at the single-cell level in melanocytic nuclei in their natural context, which makes it a promising tool in the histopathology of melanocytic lesions and in the study of melanocytic tumor progression.
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PMID:In situ detection of supernumerary aberrations of chromosome-specific repetitive DNA targets in interphase nuclei in human melanoma cell lines and tissue sections. 154 28

The cytoskeleton is considered to be important for maintaining cell shape and facilitating cell movement. In the present study, the expression of cytoskeletal components is examined in benign and malignant melanocytic skin tumors. Paraffin sections of 75 cases (25 each of nevocellular nevus, primary malignant melanoma, and cutaneous metastases of malignant melanoma) were stained with antibodies to tubulin, myosin, actin, and vimentin using a three-step immunoperoxidase method. The staining results were assessed independently for tumor cells and stroma cells in comparison to inbuilt reference structures. Vimentin is found in all melanocytic lesions in the tumor as well as in the stroma cells. In malignant lesions, the tumor cell staining intensity varies between neighboring regions; particularly in malignant melanoma the staining is pronounced in the tumor periphery (chi 2 test: p less than 0.05). Actin is only weakly positive in nevus cells and primary melanoma tumor cells, but strongly expressed in metastatic tumor cells (p less than 0.001). Nevus fibroblasts are only weakly positive, whereas the stroma fibroblasts in the malignant lesions are strongly positive (p less than 0.001). The same is true for myosin and tubulin expression in dermal fibroblasts (p less than 0.001), whereas the tumor cells are equally (weakly) positive in all melanocytic lesions. Our study shows that there are significant differences in the immunohistochemical expression of cytoskeletal components in various melanocytic tumors. There is an elevated expression of vimentin and actin in the tumor cells, particularly of metastatic lesions. However, the most pronounced differences are found in the dermal fibroblasts.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Expression of cytoskeletal components in melanocytic skin lesions. An immunohistochemical study. 202 88

Paraffin sections of formalin-fixed tumor samples from 26 patients with neuroendocrine (Merkel cell) carcinoma of the skin (NECS) were studied immunohistochemically with three monoclonal antibodies to low molecular weight keratin (MAB-K) and with antibodies to leukocyte common antigen (LCA), neurofilament (NF), neuron-specific enolase (NSE), S100 protein (S100), and chromogranin (CGN), to investigate the relative diagnostic value of these antibodies. Samples from 20 lymphomas, 10 non-oat cell undifferentiated carcinomas, 10 oat cell carcinomas, and 10 melanomas served as controls. Keratin was found in 25 of the 26 NECS and in all undifferentiated and oat cell carcinomas. A ball-like immunostaining for keratins, resembling an inclusion body was seen only in cases of NECS and some carcinoids. Neurofilament, NSE, and CGN were expressed by fewer NECS than was keratin and all NECS were negative for LCA and S100. None of the lymphomas and melanomas contained detectable keratin, NF, NSE, or CGN. Only the lymphomas stained with LCA. Only the melanomas were S100-positive. It is concluded that keratin is the most useful single discriminating marker in the separation of neuroendocrine (Merkel cell) carcinoma of the skin from lymphoma, melanoma and, when the characteristic inclusion-like pattern is seen, from metastatic oat cell carcinoma.
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PMID:The use of antikeratin antibodies in the immunohistochemical distinction between neuroendocrine (Merkel cell) carcinoma of the skin, lymphoma, and oat cell carcinoma. 242 28

Paraffin sections of 110 histologically proven malignant melanomas were incubated with a polyclonal antibody against S-100-protein. The avidin-biotin-peroxidase technique was used. A positive reaction was found in 109 cases. The staining pattern was inhomogeneous, suggesting heterogeneity within the tumor. The tumor thickness was measured in HE sections and corresponding sections that had been incubated with an antibody against S-100 protein. The results were as follows: 48.5% of the melanomas incubated with anti-S-100 protein showed a greater tumor thickness than the HE sections. The deviation between the two criteria was 15%. Four cases with the histological diagnosis of "melanoma in situ" showed S-100-positive cells within the subepidermal inflammatory infiltrate. Incubating sections of malignant melanoma with anti-S-100-protein facilitates the recognition of neoplastic cells within the inflammatory infiltrate.
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PMID:[Demonstration of S 100 protein in malignant melanoma of the skin. Pattern of distribution and significance for determination of tumor thickness]. 266 1

Patterns of basement membrane deposition were investigated in benign and malignant naevo-melanocytic lesions using antibodies to type IV collagen and laminin. Paraffin sections required pretreatment with 6 M guanidine-HCl in addition to pepsin pretreatment. Basement membrane deposition was found around clusters as well as individual naevo-melanocytic cells in contact with dermal stroma. However, between keratinocytes and intra-epidermally located naevo-melanocytic cells, basement membrane immunostaining could not be detected. Tumour cell-stromal interaction is apparently a prerequisite for basement membrane deposition in naevo-melanocytic lesions. Basement membrane discontinuities, in the absence of inflammatory infiltrate, appeared, in doubtful cases, to be evidence in favour of malignant melanoma. The general pattern of basement membrane deposition in benign and malignant lesions was found to be similar and therefore of no help in differential diagnosis. Identification of hyaline bodies, which show immunoreactivity with antibodies to basement membrane components, may be helpful in distinguishing between Spitz naevi and malignant melanomas. Detection of vascular invasion, a prognostic indicator in malignant melanoma, is facilitated by basement membrane immunostaining.
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PMID:Basement membrane deposition in benign and malignant naevo-melanocytic lesions: an immunohistochemical study with antibodies to type IV collagen and laminin. 277 16

MO4 mouse fibrosarcoma cells, B16 mouse melanoma cells, HeLa human cervical carcinoma cells, and LICR (LOND)-HN-4 human laryngeal carcinoma cells were shown to invade into precultured fragments of 9-day-old chick cardiac muscle in three-dimensional culture. Paraffin sections from such cultures were stained with an antiserum against chick heart following the unlabeled antibody enzyme method. The immunostaining demonstrated (1) differences in the rate and the way by which the four types of malignant cells occupied and replaced the chick cardiac muscle, and (2) the phagocytic activity of the four types of invading cells in three-dimensional culture.
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PMID:Immunohistochemical study of embryonic chick heart invaded by malignant cells in three-dimensional culture. 718 86

Paraffin-embedded tissue from the primary tumours of 116 patients with malignant melanoma, and in 40 cases also from corresponding metastases, were examined for accumulation of p53 protein. The fraction of tumours with positive p53 immunostaining was 13% in the least invasive and 36% in the most invasive primary lesions and 48% in the metastases. Where comparisons could be made, both the level and pattern of p53 immunoreactivity were the same in the primary and metastatic tumours. Nine (50%) patients with p53-positive and 34 (39%) with p53-negative primaries relapsed during the first 5 years, but no difference in disease-free period was observed between the two groups. However, an overall longer survival time was observed among patients with p53-positive primaries, especially for those with tumours less invasive than 3.0 mm. Notably, all 11 patients in this group were alive 5 years after diagnosis of the disease, whereas 15 out of 70 (21%) patients with p53-negative tumours died in same period. The results show that an increased level of p53 protein does not indicate increased degree of malignancy in melanoma, but rather suggests a more favourable disease progression.
Melanoma Res 1995 Jun
PMID:Accumulation of p53 protein in human malignant melanoma. Relationship to clinical outcome. 764 May 20

Syntactic structure analysis was carried out successfully on 92 paraffin embedded uveal melanomas, taken from patients with a minimum follow up of 5 years. This simple, fast, and reproducible method of describing the tumour architecture has been significantly correlated with malignancy in tumours from several sites. Paraffin sections 5 microns thick, were cut and stained with haematoxylin and eosin. Tumours were classified according to a modification of the Callender classification. A minimum spanning tree (MST), using the centre points of tumour nuclei, was constructed in five randomly chosen fields with an interactive digitising video overlay system. Ten syntactic structure features were derived from each MST; subsequently, the mean and standard deviation of the five fields analysed were calculated for further statistical analysis. Reproducibility was acceptable with a mean correlation coefficient of 0.70. In univariate survival analysis, the percentage of points with three neighbours yielded prognostic significance (p < 0.05). Minimum spanning tree variables were compared (chi 2 test) with classic tumour prognosticators and there was a significant correlation between Callender cell type and the following MST parameters: mean number of points (p < 0.003); MST length (p < 0.003); mean line length (p < 0.01); number of nuclei with one neighbour (p < 0.004); number of nuclei with two neighbours (p < 0.02), and number of nuclei with three neighbours (p < 0.005). Syntactic structure analysis is an evolving technique, but may be able to mathematically (and reproducibly) describe melanoma architecture across the spectrum of the Callender classes. This would also allow architectural grading of tumours within the specific Callender groups, providing more precise prognostic information. Further modifications of this technique are necessary to optimise prognostic potential when applied to uveal melanomas.
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PMID:Syntactic structure analysis in uveal melanomas. 784 86

p53 alterations at the DNA, mRNA and protein levels were studied in tumour metastases sampled from 30 patients with malignant melanoma. Paraffin-embedded sections from these and an additional 12 patients were examined for the presence of p53 protein. TP53 gene aberrations were found in 7 of 30 (23%) of the patients, six of which showed loss of heterozygosity (LOH). Point mutations were detected in only two cases, one of which had LOH whereas the other was non-informative. Increased levels of p53 mRNA were present in only one tumour with, but in six cases without, detectable DNA abnormalities. Four of the latter and six tumours with normal transcript levels had immunohistochemically detectable levels of p53 protein. In 25 cases in which corresponding primary and metastatic lesions could be compared, closely similar immunoreactivity patterns were observed. Increased expression of the MDM2 gene was found in only one tumour in parallel with overexpression of p53. Altogether, the data indicate that inactivation of the p53 regulatory pathway is not of major significance in the tumorigenesis of malignant melanoma. However, a significant association was found between p53 immunoreactivity and the relapse-free period in patients with superficial spreading melanoma. That increased protein expression was predominantly found in tumours without DNA alterations might suggest a role for the wild-type p53 protein in restricting malignant cell proliferation in these cases.
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PMID:TP53 allele loss, mutations and expression in malignant melanoma. 790 77


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