Epiluminescence microscopy: a new approach to the early detection of melanoma.
ELM is a new approach to the diagnosis of pigmented skin lesions that holds considerable promise. It reveals a new dimension of in vivo morphology that can be used when the diagnostic criteria employed in routine visual diagnosis fail. It does not add to the diagnostic armamentarium available for unequivocal lesions, but has significant value for those equivocal, small, pigmented skin lesions that pose major diagnostic problems even for experienced clinicians. Prerequisites for a sensible approach to ELM include recognition of new morphologic ELM criteria and employment of these criteria in an analytic process called pattern analysis. As in clinical dermatology, ELM depends heavily on a learning process and, of course, on experience. ELM increases diagnostic accuracy for pigmented skin lesions in that it helps to distinguish between melanocytic and non-melanocytic pigmented lesions, and between benign and malignant growth patterns. Thus, ELM has the potential to overcome the diagnostic limitations encountered in clinical dermatology when small, early pigmented lesions are encountered that do not yet express the full complement of diagnostic features needed to arrive at a correct diagnosis. The fact that it is a noninvasive, in vivo method makes it even more attractive as a diagnostic tool in clinical practice. ELM already has proven to be of great practical value in several centers by increasing the probability that early melanoma will not be overlooked and by helping to prevent unnecessary major surgery in patients in whom a non-melanocytic or benign pigmentary lesion is suspected clinically to be a melanoma. It eventually may prove valuable for patients with dysplastic nevi by helping determine which lesions need to be removed. Of course, ELM also has limitations. It does not provide 100% diagnostic accuracy and is of little help in small lesions that are pigmented maximally and uniformly because these do not reveal the criteria necessary for ELM pattern analysis. At this stage, therefore, ELM does not replace histopathologic examination. Undoubtedly, ELM can be improved, and continued studies will reveal just how reliable the individual criteria discussed here eventually will prove to be in clinical practice. This requires continuing to accumulate and analyze data, and instituting teaching programs to familiarize dermatologists with ELM criteria and their use in pattern analysis. It is certain, however, that, just as clinicians have learned to employ the "ABCD" rules in visually recognizing and diagnosing melanoma, they will learn this new and more subtle approach to the previously unknown morphologic features that characterize benign and malignant pigmentary lesions on ELM.(ABSTRACT TRUNCATED AT 400 WORDS)