Abstracts from the Joint Meeting of the International Society for Digital Imaging of the Skin (ISDIS) the International Confocal Group (ICG) and the International Dermoscopy Society (IDS) in conjunction with the 2014 American Academy of Dermatology March 22 2014 Denver CO USA

摘要

Dermoscopy is a non-invasive imaging technique that improves accuracy in the diagnosis of melanoma. It has been associated with a reduction in the false-positive detection rate and a subsequent decrease in unnecessary excisions. In vivo confocal microscopy is also a non-invasive technique which allows the examination of the skin at cellular resolution; its diagnostic accuracy has been evaluated by several studies concluding that the use of this novel technique provides a significant improvement in melanoma detection.The number-needed-to-treat (NNT) ratio is an effective method for measuring accuracy in melanoma detection. The aim of the present study was to assess the impact of RCM analysis on the number of dermoscopically equivocal pigmented lesions excised for every melanoma, in a clinical setting.Three hundred and forty-three consecutive patients presenting with dermoscopically equivocal lesions, assumed to be melanocytic neoplasms based on clinical and dermoscopic features, were prospectively enrolled. Dermoscopy and confocal microscopy diagnosis were made by dermatologists with expertise in both techniques. Histopathological assessment was considered as the reference standard. The main outcome was NNT, calculated as the proportion of dermoscopically and RCM equivocal lesions excised for every melanoma. Secondary outcomes included sensitivity, specificity, positive predictive value and negative predictive value of each technique for diagnosing melanoma.Results:Dermoscopy alone obtained a hypothetical NNT of 3.73; the combination of dermoscopy and RCM identified 264 equivocal lesions that qualified for excision, 92 of which were confirmed to be a melanoma, resulting in an NNT of 2.87, whereas the analysis of RCM images classified 103 lesions as melanoma, with a consequent NNT of 1.12. The difference in NNT was statistically significant between the three groups (P < 00001). There was no significant improvement in sensitivity when comparing the combination of dermoscopy and RCM with RCM alone (94.6% vs. 97.8%; P = 0.043). However, the differences between specificities were statistically significant (P < 1×10⁶), favouring RCM alone.