White’s group, along with colleagues from the University of Southern California School of Medicine, Los Angeles, has been working with a human-derived monoclonal antibody (which may be used on routinely processed, paraffin-embedded tissue) that is directed against a cytoplasmic, rather than a cell-surface, antigen. The researchers hope was that this monoclonal antibody, which White said is different from the type common to all laboratory animal-derived systems in that it can specifically recognize malignant melanoma antigens, would be able to distinguish all malignant melanomas from all unusual nevi.
Although this hope was not realized in their preliminary study—some rapidly growing but benign nevi did pick up the antibody—White said he still believes the technique is potentially useful because the two types of lesions showed a difference in the intensity of staining. Also, he thinks some of the patterns of staining noted in the malignant melanomas may have prognostic implications. As work continues, White says, “It’s not the gold standard yet, but this technology may allow us to get there.”
While a number of researchers concentrate on the reported association between unusual moles and melanoma, Robert J. Friedman, MD, a clinical instructor in dermatology at the NYU School of Medicine, told his colleagues in New Orleans that recent microscopic examination of step sections (every 2 mm) of 1049 malignant melanomas failed to confirm the reports in the literature of direct contiguity.
Friedman said that 85% of the samples he studied did not have a precursor lesion associated with them. “Of the 15% of malignant melanomas that did have an associated mole,” he added, “only 3.7% of those moles had the features of a dysplastic nevus—and only 0.2% of the malignant melanomas had an associated congenital mole” Therefore, he concluded that malignant melanomas arise most often without an associated mole. And in the case of the small number that do arise in such association, some of the moles may be dysplastic and very few are congenital.
Nevertheless, he cautions, when melanomas were associated with moles, the latter were usually larger than 6 mm in diameter, so it is possible that persons with multiple large moles are at greater risk for melanoma. “And although it appears that dysplastic nevi can develop histologically in contiguity with melanoma,” he said, “more importantly, it appears that they are a marker for the development of malignant melanoma. Therefore, careful clinical follow-up of patients with dysplastic nevi is in order to try to reduce the risk of advanced melanoma.” Shop with pleasure with most reliable pharmacy you have ever seen, paying less for your generic sildenafil online always being sure you are being treated with all due respect, being an important customer whose interests are respected and taken into account.