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Query: UMLS:C0027960 (mole)
 21,279 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Proteolytic activities were measured in extracts of human skin melanoma, lymphatic metastasis and in nonmalignant naevi by using various proteinase substrates as well as plasminogen activator assay. pH-optima for hydrolysis of various proteinase substrates by these tumors were found to be essentially the same as in healthy human skin. Melanoma extracts were found to especially readily hydrolyze N-alpha-benzoyl-DL-arginine beta-naphthylamine (BANA) at pH 5.8 in the presence of 1 mmol/l dithiothreitol and EDTA (cathepsin B1-like enzyme) as well as histones and p-tosyl-L-arginine methyl ester (TAME) at pH 7.5, and showed increased capacity to activate plasminogen when compared to nonmalignant naevus. The possible role of proteinases in malignant melanoma is discussed.
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PMID:Proteolytic enzymes and plasminogen activator in melanoma. 3 88

Pathological features of twenty-one cases of malignant melanoma studied in the University of Nigeria Teaching Hospital, Enugu during the period January, 1974 to December, 1975 are presented. Malignant melanoma accounted for 2.4% of all tumours and 4.5% of all malignant tumours, greatest age incidence being in the fifth to seventh decades. The male to female sex ratio was 2:1. 73.2% of cases were of the nodular variety. 81% melanomas occurred on the sole of feet validating the hypothesis that the pigmented skin in Africans is resistant to malignant melanoma. Melanoma in Nigerians would appear essentially to be arising from epidermal melanocytes and not from preexisting naevus cells. Hence we do not feel prophylactic removal of plantar moles as suggested by Onuigbo (1975) is desirable. Histologically, there was no clear association between the cell types and the kind of melanoma or invasion of the tumour. The difference in behaviour and natural history of malignant melanoma would appear to have a bearing on the local tissue and also general immune mechanisms of the host.
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PMID:Malignant melanoma in Nigeria-pathological studies. 9 49

This paper reports a case of malignant Melanoma in a 53 year old man with simultaneous development around the lesion of an acromic area with the characteristics of the so called Halo Navi phenomenon. Furthermore the patient presented lesions in other skin areas not related to apparent nevi. Microscopic tissue examination showed an inflammatory infiltrate in the depigmented zone which tended to surround and to include the melanoma periphery. This supports the conclusions of other publications linking these infiltrates with immunological phenomena tending to eliminate the tumor. A review is made of the new physiopathogenic criteria of the development of vitiligo.
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PMID:[Halo nevi and vitiligoid phenomena in a case of melanoma]. 39 35

Melanoma specific protein is immunologically related to altered naevus cell cytoplasm. It is excreted by patients with malignant melanoma but in no other malignancy. The protein has been detected in patients with actively developing halo naevi but not when repigmentation is taking place. It also occurs in patients with very active vitiligo but in no other pigment condition we have studied. It is suggested that the protein is a marker of active destruction of naevus cells by immune mechanisms and that the release of toxic materials during this immune reaction may be responsible for the production of the halo phenomenon and for the areas of vitiligo that may be seen elsewhere on the skin.
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PMID:Melanoma specific protein: occurrence in the urine of patients with halo naevus and vitiligo. 67 52

Twenty-one intradermal nevi were studied by morphometric methods in an attempt to morphologically characterize the two types of nevus cell--epithelioids, type A, and fusiforms, type C--and to quantify the differences between them. Morphometric parameters of the intradermal nevi were compared with similar parameters of melanocytes and melanoma cells so that the maturation rates of the nevi cells could be established and to see if the parameters might indicate the degree of malignancy. Superficial nevus cells were differentiated from deep cells by their larger size and larger nuclear area. Nuclear area appeared to have potential for differentiating benign from malignant tumors. Decrease in cellular area appeared to indicate maturation rather than atrophy. Melanoma cells were differentiated by their larger size. Cell nuclear perimeter appeared to have confirmatory value, while cell perimeter was inconclusive.
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PMID:Application of morphometric methods to the cytologic study of intradermal nevi. 129 28

Although most examples of cutaneous malignant melanoma are easily recognized by their clinical appearances, in some cases this serious neoplasm may clinically simulate other less serious forms of skin cancer or benign processes. This study was undertaken to assess both the sensitivity of clinical diagnosis of cutaneous malignant melanoma and the efficacy of biopsies of clinically unsuspected melanomas in yielding specimens on which complete and accurate histologic assessments could be made. A retrospective analysis of 1784 cases of histologically proven melanomas diagnosed between 1985 and 1990 was performed in search of lesions not clinically suspected. Biopsy techniques used to sample these lesions were subjected to critique of their efficacy in yielding specimens that could be accurately diagnosed and completely assessed histologically. Of 1784 histologically proven primary cutaneous melanomas, 583 were not clinically suspected, yielding a sensitivity of 67%. Clinical diagnosis included nevi (33%), no diagnosis (17%), multiple diagnoses (13%), basal cell carcinoma (12%), keratosis (9%), and lentigo (9%) among others. The biopsy methods used to sample these lesions were shave (56%), excisional (24%), punch (11%), curettage (2%), and undetermined (6%). Eighty-six percent of shave biopsies could be accurately assessed while only 32% of punches and no curettages provided sufficient material for both definitive and complete evaluation of melanomas. Eighteen percent of specimens histologically reviewed were considered inadequate for complete evaluation. In 34%, the actual diagnosis of melanoma was uncertain because of inability to assess diagnostic features as a consequence of the biopsy technique. Melanoma may be unsuspected clinically in a significant number of cases and may be mistaken for less serious cutaneous neoplasms.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Sensitivity of diagnosis of malignant melanoma: a clinicopathologic study with a critical assessment of biopsy techniques. 136 17

A total of 761 melanocytic lesions were studied to elucidate the usefulness of clinical features for the diagnosis of dysplastic naevi. Characteristics associated with high (irregular border, irregular pigmentation), intermediate (black coloured areas, largest diameter greater than 0.5 cm, change of size, change of colour) and low diagnostic efficiency could be defined. Combinations of criteria had high sensitivities: at least one of the following four criteria was positive in 96% of the dysplastic naevi and in all melanomas with less pronounced clinical characteristics: irregular border, irregular pigmentation, greatest diameter greater than 0.5 cm, black coloured areas. A lesion is therefore unlikely to be a dysplastic naevus or a melanoma if all these criteria are absent. When change of size and change of colour were analysed in addition to the features mentioned above a sensitivity of 0.96 was found for at least two of these six criteria. At least three of these six criteria were observed in all melanomas with less pronounced clinical characteristics. However, a rather low specificity (0.19 for at least one of four positive criteria, 0.20 for at least two of six positive criteria) indicated that dysplastic and non-dysplastic naevi cannot be clinically differentiated with acceptable certainty. With less stringent histological criteria approximately twice as high specificities were found. Specificities were about twice as high in a subgroup of patients with at least one proven dysplastic naevus besides the lesion under diagnostic consideration. This facilitates the identification of individuals at risk of developing a melanoma.
Melanoma Res
PMID:The usefulness of single and combined clinical characteristics for the diagnosis of dysplastic naevi. 142 93

Melanoma cells have surface markers that are expressed differently than in normal melanocytes and nevus cells. Monoclonal antibodies may define a phenotypic map of the various melanocytic lesions and can be used in immunohistopathology and immunoscintigraphy. Monoclonal antibodies directed against melanoma-associated glycoproteins and glycolipids are being tested for therapy. Rearrangements or deletions on chromosome 1, 6, and 7 are the most frequently observed cytogenetic abnormalities. Molecular studies have not given a clear picture. A subset of HRAS alleles has been reported to be associated with melanoma. NRAS activation by point mutation has been found in one fourth of the cases. Allele losses at different loci have been reported. Genetic linkage studies have given conflicting results on the presence of a gene for the melanoma-dysplastic nevus syndrome on the short arm of chromosome 1.
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PMID:Cellular and molecular biology of melanoma. 143 44

Based on the clinicopathological classification of distinct stages of tumor progression in the melanocytic system, we have investigated the in vitro growth patterns and requirements of normal melanocytes and melanocytes isolated from different lesions of melanoma progression. Normal melanocytes depend on a combination of insulin-like growth factor (IGF-I) or insulin, 12-O-tetradecanoyl phorbol-13-acetate (TPA), alpha-melanocyte stimulating hormone (alpha-MSH), and basic fibroblast growth factor (bFGF) for in vitro proliferation. Nevus cells display a reduced need for TPA and are largely independent of bFGF. Both melanocytes and nevus cells have a finite lifespan in vitro and show no spontaneous transformation, whereas melanoma cells can be grown indefinitely in vitro. Cells from primary melanomas require only IGF-I or insulin for continuous growth, and metastatic melanoma cells can proliferate in base medium without addition of any growth factors or proteins. This progressive growth autonomy is paralleled by an increased competence for endogenous growth factor production. Among these growth factors, bFGF and melanoma growth-stimulatory activity (MGSA) act in an autocrine fashion. Melanoma-derived growth factors without apparent autocrine function, such as platelet-derived growth factor A and B (PDGF-A and PDGF-B) and transforming growth factor-alpha (TGF-alpha), might still be important for melanoma growth by stimulating surrounding normal fibroblasts, endothelial cells, or keratinocytes to secrete growth-promoting factors. The significance of growth factors such as transforming growth factor-beta (TGF-beta) and melanoma-inhibiting activity II (MIA II), which have a potentially negative autocrine function, remains unknown. The successful propagation of melanocytic cells of all stages of melanoma progression has yielded valuable insight into the mechanisms of growth regulation and malignant transformation.
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PMID:In vitro growth patterns of normal human melanocytes and melanocytes from different stages of melanoma progression. 144 12

Results obtained using a computerized image analysis system as an aid to clinical diagnosis of melanoma are reported. The system comprises a colour television camera connected through a digitizing board to a 386 personal computer. By means of original algorithms able to measure the shape, the colours and texture of a pigmented lesion of the skin, the system provides eight on/off indicators that are matched with the histological diagnosis to identify benign and malignant pigmented lesions. The chances that a given lesion is malignant increase with the increasing number of positive indicators. The training field of the system was constituted of images and data of 169 cutaneous lesions in 165 patients. Taking two positive indicators as the threshold between pigmented benign and malignant lesions, the efficiency of the system is 0.98, the positive predictive value is 0.45 and the negative predictive value is 0.95. These values were confirmed in a series of 44 pigmented lesions, 10 of which were melanoma, that constitute the present test series. The authors conclude that this computerized image analysis system should be regarded as a useful aid to diagnosis for a non-expert clinician. The system limit is transformation within a naevus.
Melanoma Res 1992 Sep
PMID:Results obtained by using a computerized image analysis system designed as an aid to diagnosis of cutaneous melanoma. 145 Jun 70


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