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

Staining of argyrophilic nucleolar organizer regions (AgNORs) is a histological technique that has been assayed on a vast array of cutaneous tumors in order to help distinguish benign from malignant lesions. In a number of papers, malignant melanomas have been found to have a higher number of black nucleolar and extranucleolar dots (i.e. AgNORs) than benign nevi, including Spitz nevus. The technique may be used for prognostic purposes, as a recent paper suggests. Melanomas with more than 3.62 AgNORs/cell have a higher probability to develop metastasis than melanomas with fewer AgNORs. The problems such an apparently simple, fast and reproducible technique may pose are discussed in detail.
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PMID:Prognosing melanomas: the argyrophilic nucleolar organizer region approach. 144 80

Pagetoid infiltration of the epidermis by melanocytes, also termed 'buckshot spread', is regarded by some as being essential for the confident histopathological diagnosis of primary cutaneous melanoma. We have reviewed 340 melanomas received over a 23 year period to assess the frequency of pagetoid infiltration and whether its presence bears any relationship with other histopathological features. Conspicuous pagetoid infiltration was present in 32.1% of the lesions and occasional melanocytes were observed within the stratum spinosum in a further 23.5% of cases. However, no melanocytes could be seen above the basal layer in 44.4% of the melanomas. The presence of pagetoid infiltration showed inverse correlation with tumour thickness, level of invasion, growth phase and mitotic count, and positive correlation with the presence and severity of regression. No association was found with the site of the primary lesion, melanocytic dysplasia or lentigo maligna in the adjacent epidermis, or with the presence of residual benign naevus cells in the epidermis. Thus, pagetoid infiltration of the epidermis was commonest in in situ or thin horizontal growth phase melanomas, and was conspicuous in only one-third of cases. While its presence is useful in the diagnosis of melanoma, its absence should not preclude it.
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PMID:Pagetoid infiltration in primary cutaneous melanoma. 843 52

Reflectance spectrophotometry from 420 to 780 nm on 31 primary melanoma and 31 benign nevi has been performed by using an external integrating sphere coupled to a spectrophotometer. Measurements show that reflectance spectra of melanoma and nevi manifest dissimilar patterns. From these spectra four variables, whose physical and/or physiological meanings remain to be investigated, have been derived. All of them are significantly different when compared between melanoma and nevi. A discriminant function between the two groups of lesions has been determined by using a stepwise discriminant analysis, resulting in a test with a sensitivity of 90.3% and a specificity of 77.4%. This method of discrimination between melanoma and nevi seems to have a discriminating power almost equal to that of a clinical judgement from a specialized medical doctor, thus suggesting a new method for screening skin pigmented lesions.
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PMID:In vivo spectrophotometric evaluation of neoplastic and non-neoplastic skin pigmented lesions. II: Discriminant analysis between nevus and melanoma. 162 Jul 28

Antigen expression was studied by immunohistochemistry in 133 human melanocytic skin lesions to gain insight into the initial steps of tumor development, i.e. in particular the change from melanocytes to benign nevi. We refer to the proposed progression model of Clark and co-workers. The following types of antigens were investigated: (i) intermediate filament antigens (vimentin), (ii) melanoma-associated antigens (HMB-45, NKI/C3, MA-930, LS59), (iii) proliferation-associated antigens (S-100, Ki67, Ro/SSA, calmodulin), (iv) progression-associated antigens (HLA-DR, ICAM-1), and (v) basal membrane antigens (bullous pemphigoid antigen, laminin, fibronectin, collagen type IV). The intensity of expression and the topography of immunoreactive pigment cells were compared with the stage of tumor progression. Special attention was paid to the early steps of this process, i.e. the disturbance of the epidermal melanin unit and the development of melanocytic ("nevocellular")nevi. A dramatic shift of antigen expression (antigen types [i] to [v]) was noted in benign nevi compared with melanocytes. Nevi with cellular atypia disclosed a tendency towards an increased percentage of tumor cells reactive for melanoma- and progression-related antigens (types [ii] and [iv]). However, there was no clear cut level of distinction of antigen expression (types [i] to [v]) between benign and primary malignant melanocytic tumors. So-called dysplastic nevi resembled benign tumors or melanocytes rather than malignant melanoma. Metastatic melanoma of skin showed a relatively high number of Ki67-positive, cycling melanoma cells. The results have a bearing on the concepts of melanocytic nevus ontogenesis and "maturation". It appears that melanocytes lose maturity on their way down to the dermis in contrast to traditional concepts (Abtropfung); this might be of importance for our understanding of melanoma development in association with melanocytic nevi. Our findings are discussed with regard to Clark's model of tumor progression.
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PMID:The initial steps of tumor progression in melanocytic lineage: a histochemical approach. 174 97

Tumour cell proliferation and particularly tumour cell motility are considered to be essential pre-requisites for invasive tumour growth. Despite abundant in vitro data on tumour cell motility, the behaviour of tumour cells in complex human tumour tissues is yet unknown. In this study, estimates of proliferation and motility are statistically derived from morphological tumour patterns in human melanocytic skin tumours. Two-dimensional, discrete, random computer simulations of tumour growth were carried out in order to determine the influence of tumour cell proliferation and motility on morphological patterns. A set of binary morphological criteria turned out to facilitate a significant estimate of the relative probabilities of motility and proliferation (CART analysis). When the same morphological criteria were applied to H & E stained slides of 45 melanocytic skin tumours, benign common nevi showed a predominance of motility, whereas primary and metastatic malignant melanoma revealed a predominance of proliferation. The direct assessment of the number of proliferating cells by Ki-67 staining shows a steep increase from benign nevi to primary and metastatic melanoma. These data provide first evidence that in benign common nevi the overall motility exceeds the very low degree of proliferation, whereas in malignant melanocytic tumours proliferation considerably exceeds tumour cell motility.
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PMID:Computer simulation analysis of morphological patterns in human melanocytic skin tumours. 179 95

A silver colloidal technique to demonstrate argyrophilic proteins of the nucleolar organizer regions (AgNORs) was performed on sections of 20 cases of malignant melanoma (MM) associated with underlying benign nevus (BN). In these cases, significant different AgNOR counts were found for MM and BN. In addition, this technique permitted the identification of melanocytic cells located between malignant and benign cells showing AgNOR scores intermediate (5.51) between BN (2.6) and MM (7.71) with a more complex and bizarre morphology than that observed in BN. The AgNOR technique can be suitable in the identification of residual nevus cells in MM, especially when their number is minimal and the common histologic criteria are unsatisfactory; it can also increase the understanding of the natural history of MM.
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PMID:Argyrophilic nucleolar organizer region counts in malignant melanoma associated with benign intradermal nevus. 180 85

A clinically benign appearing nevus was surgically excised from the conjunctiva of a 13-year-old girl because of complaints that it had recently enlarged. Histologically, the melanocytic lesion displayed considerable cytologic atypia and showed signs that were consistent with malignant transformation. Because of the rarity of conjunctival melanomas in children, the case was reviewed by several experienced pathologists and dermatopathologists whose diagnoses ranged from benign nevus with atypia to malignant melanoma. When the biologic potential of certain melanocytic lesions cannot be accurately predicted histologically, treatment and follow up must be individualized. Physicians must weigh the perceived risks and disadvantages of treating a histologically indeterminate tumor against the consequences of "under" treatment if the lesion is, in fact, biologically malignant.
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PMID:Borderline melanocytic tumor of the conjunctiva: diagnostic and therapeutic considerations. 195 62

Benign nevi, dysplastic nevi, and primary and metastatic malignant melanomas were evaluated for the presence of sex hormone binding and estrogen receptor protein. We have confirmed the observation of Ellis et al. that some pigmented lesions possess sex hormone-binding proteins. We could not demonstrate a true estrogen receptor in any benign nevi, dysplastic nevi, primary melanomas, or metastatic melanomas. Thus the ability to bind estrogen or progesterone does not correlate with the presence of a true estrogen receptor. Lack of nuclear estrogen receptors suggests that the influence of estrogen on the pathophysiology of melanoma or of benign melanocytic nevi may not be significant.
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PMID:Absence of estrogen receptors in dysplastic nevi and malignant melanoma. 221 19

All cutaneous nevomelanocytic specimens accessioned for histopathologic examination at Massachusetts General Hospital, Boston, in 1950, 1960, 1970, and 1987 were reviewed. The specimens were categorized as malignant melanoma, acquired or congenital benign nevi, blue nevi, spindle and epithelioid cell nevi, and dysplastic nevi. Other processes such as lentigines were excluded. There was a threefold increase in percentage of patients having nevomelanocytic lesions removed (1.5% in 1950 to 4.6% in 1987) compared with total surgical cases over the 37-year period. A progressive increase in numbers and percentages of dysplastic nevi (among nevomelanocytic surgical cases) was noted over a 37-year interval--2 cases (1% of nevomelanocytic cases) in 1950, 4 cases (2%) in 1960, 23 cases (5%) in 1970, and 189 cases (12%) in 1987. These findings confirm the existence of dysplastic nevi by histopathologic criteria as early as 1950 and illustrate the frequencies of various nevomelanocytic surgical specimens among all surgical specimens at four points in time over a 37-year period at a major referral center for pigmented lesions.
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PMID:Frequency of dysplastic nevi among nevomelanocytic lesions submitted for histopathologic examination. Time trends over a 37-year period. 232 91

The technique of silver (Ag) staining of nucleolar organizer region-associated proteins (AgNORs) has been shown to be of value in differentiating between benign and malignant cells. We have studied 33 borderline melanocytic lesions, in which a diagnosis of melanoma had been seriously considered, in order to assess the value of this technique in a commonly encountered diagnostic situation. We found that benign naevus cells possessed single compact or granular AgNORs, whereas some malignant melanocytes possessed large, often loosely arranged groups of AgNORs. However, the pattern of AgNORs observed in melanocytes of some atypical but benign lesions was also seen in some melanomas. The differential diagnosis of borderline melanocytic lesions is not clarified by use of the AgNOR technique.
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PMID:The value of nucleolar organizer region staining in the differential diagnosis of borderline melanocytic lesions. 246 98


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