Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0025202 (melanoma)
 69,561 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

HMB-45 is a monoclonal antibody directed against human melanoma cells and which stains epidermal and dermal melanoma cells, the junctional components of common and dysplastic melanocytic nevi, and melanocytes in fetal skin. In addition, melanocytes in a variety of reactive conditions have been shown to label with HMB-45, as have dermal melanocytes within Spitz and dysplastic nevi. No melanocytes in normal adult epidermis or in the dermis of common nevi have stained with HMB-45. In order to better understand the properties of this antibody, and of the melanocytes that react with it, we stained cultured human melanocytes grown in a variety of conditions. Melanocytes from human foreskins were grown for 2-3 weeks in MCDB 153 medium supplemented with insulin, epidermal growth factor, and bovine pituitary extract as a mixed population of keratinocytes and melanocytes. Some cells were transferred to basal medium MCDB 153 (unsupplemented) for periods ranging from 3-5 days, and a subset of these were returned to growth-factor supplemented medium. In all cases, S100 staining was used to confirm the presence of melanocytes. Melanocytes grown in complete medium showed strong granular cytoplasmic staining with HMB-45. Cells transferred to basal medium showed a markedly diminished staining intensity which was reversible within 3 days upon return of the cells to complete medium. The findings suggest that expression of the protein recognized by HMB-45 may be related to a growth factor present in complete medium, but missing from basal MCDB 153.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:HMB-45 monoclonal antibody recognizes an inducible and reversible melanocyte cytoplasmic protein. 176 83

HMB-45 is generally thought of as a melanoma specific antibody; however, there are certain exceptions. It is known that most dermal nevi show no reactivity; however, the dermal nevus component within dysplastic nevi and certain Spitz nevi show positive reactivity. In order to further examine this observation, we undertook a study to examine blue nevi, both common and cellular, for the expression of HMB-45. Cases were stained with antibodies directed at both HMB-45 and S100 protein. Of 16 common blue nevi studied, 14 were positive with HMB-45, as were 6 of 6 cellular blue nevi. Staining for HMB-45 was quite variable in intensity amongst cases labelled common blue nevi. In contrast, cellular blue nevi were uniformly strongly positive. It is therefore concluded that blue nevi, including cellular blue nevi, exhibit an activated phenotype as demonstrated by HMB-45 reactivity.
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PMID:Analysis of HMB-45 immunoreactivity in common and cellular blue nevi. 193 85

An immunohistochemical study of 40 primary and secondary malignant melanomas in 27 patients, with routinely-used monoclonal antibodies, demonstrated the antigenic pattern exhibited by these tumors, as well as the frequency of aberrant positivities for epithelial cell markers. The following results were found: 95% of melanomas stained positively for S100 protein and vimentin, which is the characteristic immunohistochemical pattern in melanomas. In most cases, the primary tumor and its metastases in a given patient had the same antigenic phenotype. As for epithelial markers, 10% of melanomas stained positively for KL1 and 27.5% for EMA. Despite this relatively high frequency of KL1 and EMA positivities, in practice, simultaneous positivity for S100 protein and vimentin, confronted with the patient's history and with histologic features, firmly establishes the diagnosis of malignant melanoma in virtually all cases.
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PMID:[Immunohistochemical characteristics of malignant melanoma. A study of 40 cases and review of the literature]. 218 22

We studied six cases of heavily pigmented melanocytic lesions with features of blue nevi within the dermis, but with an additional junctional dendritic component. This compound variant of blue nevus is an uncommon lesion that has not been previously identified as a distinct histologic entity. Immunoperoxidase staining for S100 protein and counterstaining with azure B distinguished the presence of melanocytes among numerous melanophages within the dermis. The compound variant of blue nevus can be distinguished histologically from combined blue nevus, pigmented spindle cell nevus, malignant melanoma, and melanosis due to a regressed malignant melanoma. The six lesions were from three men and three women whose ages ranged from 11 to 51 years (mean, 31 years). Three lesions were located on the trunk, two on the extremities, and one on the head. After a mean follow-up period of 47 months (range, 38 to 58 months), there was no evidence of recurrence.
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PMID:Compound blue nevus: a variant of blue nevus with an additional junctional dendritic component. A clinical, histopathologic, and immunohistochemical study of six cases. 222 38

Pulmonary blastomas are rare primary tumors that consist of tubular or glandular structures embedded in an undifferentiated mesenchymal stroma. Focal cartilage, bone, and skeletal muscle as well as squamous differentiation have been described in these tumors. We report a unique case of a pulmonary blastoma showing a malignant melanoma component. Immunohistochemical stains for S100 protein and HMB-45 were positive in the areas of melanocytic differentiation.
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PMID:Pulmonary blastoma with malignant melanoma component. 222 50

A case of amelanotic malignant melanoma of the esophagus in a 76-year-old woman is reported. A whitish polypoid tumor, measuring 3 x 2 x 2.7 cm, surrounded by black pigmented mucosa, was detected in the middle intrathoracic esophagus. The tumor showed a lobulated surface lined by squamous cell layer, and had epithelioid and polyhedral cells forming alveolar clusters. Melanin pigments or stainability for the dihydroxyphenylalanine (DOPA) reaction were only observed in a few tumor cells. Junctional changes and mucosal melanosis, however, were found freely in the mucosa around the tumor. Many tumor cells showed a strongly positive immunohistochemical reaction for neuron specific enolase (NSE) and S100 protein. The patient died of widespread metastases six months after surgery. Further, a review of 106 reported cases of primary esophageal malignant melanoma, including 29 autopsies, was made; the melanomas were found to include 10 of amelanotic type, eight of which had been misdiagnosed at biopsy. Junctional changes could be found in the mucosa over or around the tumor, in four cases, and mucosal melanosis in one. Lymph node metastasis was the most frequently observed development at autopsy regardless of whether the tumor was amelanotic or melanotic. For correct diagnoses of melanomas of the amelanotic type, peripheral mucosal findings, such as junctional changes or melanosis, should be helpful; and, in order to obtain a good prognosis, a careful resection of the regional lymph nodes could prove valuable.
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PMID:Amelanotic malignant melanoma of the esophagus: case report and review of the literature. 225 5

The synthesis of S100 protein in cultured human melanoma cells was examined using metabolic labeling with [35S]methionine, immunoprecipitation with anti-S100 protein antiserum, and polyacrylamide gel electrophoresis in the presence of sodium dodecyl sulfate. Six of seven cell lines derived from melanomas synthesized relatively large amounts of S100 protein, whereas three cell lines derived from normal melanocytes synthesized lesser amounts. Synthesis of S100 protein was not detected in 10 human cell lines of nonneuroectodermal origin. Analysis of poly(A+) RNA from one melanoma cell line by Northern blot hybridization with a probe specific for the beta subunit of rat S100 protein revealed a single mRNA species of 1.0 kb coding for the human protein. Flow cytometric analysis of individual cells of two melanoma cell lines and the rat glioma cell line C6 indicated that G0/G1 cells were heterogeneous with respect to S100 protein expression, while almost all the cells in S + G2 + M expressed S100 protein. These results suggest that expression of S100 protein in G0/G1 could be a prerequisite for progression of the cells through the cell cycle.
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PMID:S100 protein expression in human melanoma cells: comparison of levels of expression among different cell lines and individual cells in different phases of the cell cycle. 229 61

The differentiation between Spitz naevus and melanoma is at times difficult. The present study was undertaken to define means to positively identify such melanocytic tumours of doubtful malignancy. Immunohistochemical staining intensity for S100 protein and neurone specific enolase (NSE) was measured in sections of 35 Spitz naevi using a microcomputer image analysis system. The data were compared with results previously obtained from 19 cases of malignant melanoma and 16 benign compound naevi. Disaggregated cells from paraffin-embedded material were stained by the Feulgen technique for DNA estimation. The nuclear DNA content distributions were measured using the same image analysis system. Compared with the malignant cases, the Spitz naevi showed significantly lower staining intensity for both S100 protein (P less than 0.0001) and NSE (P less than 0.0001). When compared with the benign compound naevi, the staining intensity was significantly lower for S100 protein (P = 0.003). The nuclear DNA distribution in Spitz naevi proved to be a normal diploid pattern in 31 cases. Four cases showed a small proportion of hyperdiploid nuclei. The results show that Spitz naevi can be significantly distinguished from malignant melanoma by staining intensity for S100 protein and NSE. A normal diploid DNA content distribution appears to be typical for Spitz naevi. Spitz and benign compound naevi show dissimilar expression of S100 protein which may indicate different patterns of differentiation in these two types of lesion. The image analysis equipment used in this study is accurate, simple to use, produces results rapidly, and is economic. Therefore, it is clinically practicable.
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PMID:S100 protein, neurone specific enolase, and nuclear DNA content in Spitz naevus. 237 May 97

Expression of intermediate filament (IF) isotypes was studied in six human and two murine melanoma cell lines. With one exception, these lines expressed IFs only of the vimentin type; neurofilament peptides, desmin and GFAP were not detected. However, the M5 human melanoma line also expressed extensive cytokeratin tonofilament arrays, as visualized by immunofluorescence with a panel of eleven monoclonal antibodies and hetero-antisera to cytokeratins; only the keratin 19-specific antibody BA16 did not react. By 2 D gel electrophoresis, five major keratin peptides were detected (keratins 7, 8, 13, 17 and 18), and an additional 57 kD peptide was detected on immunoblots with several antikeratin antibodies. Also observed in M5 cells was focal collapse of tonofilament arrays in mitotic cells. All the melanoma lines tested were positive for S100; M5 and two other cell lines were also positive for the 220-240 kD neuroectoderm-associated cell-surface differentiation antigen defined by monoclonal antibody UJ 127:11. In all the melanoma cell lines, secretion of extracellular matrix proteins (fibronectin, laminin and collagen type IV) was sparse or absent, and all were negative for the epithelial cell markers HMG-1 and HMG-2. Co-expression of keratin and vimentin by a melanoma cell line is discussed in the light of recent controversy concerning expression of cytokeratins by other neoplasms of putative neuroectodermal origins.
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PMID:Phenotypic analysis of cultured melanoma cells. Expression of cytokeratin-type intermediate filaments by the M5 human melanoma cell line. 242 48

The histologic and immunologic features of an unusual morphologic expression of nodular sclerosing Hodgkin's disease, which ahs been termed the "syncytial variant," are described. In biopsy material from 18 cases, numerous Reed-Sternberg cell variants were observed in sheets and cohesive clusters, and at least focal evidence of nodular sclerosis was present in each case. The granulocyte antibody anti-Leu M1 reacted with antigenic determinants in Reed-Sternberg cells and atypical variants thereof in 13 of the 18 cases; the lack of staining with antibodies reactive with the leukocyte common (T200) antigen (PD7/26), keratin (AE1), and S100 protein (polyclonal anti-S100) was helpful in excluding non-Hodgkin's lymphoma, carcinoma, and melanoma, respectively. This unusual form of nodular sclerosing Hodgkin's disease is important to recognize, since it may simulate metastatic neoplasms, thymoma, and non-Hodgkin's lymphoma.
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PMID:The "syncytial variant" of nodular sclerosing Hodgkin's disease. 242 45


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