ABCD RULE OF DERMATOSCOPY - A NEW PRACTICAL METHOD FOR EARLY RECOGNITION OF MALIGNANT-MELANOMA

To improve and facilitate differentiation between benign melanocytic n aevi (MN) and malignant melanoma (MM), a new ABCD rule has been develo ped on the basis of semiquantitative analysis of 31 features of surfac e microscopy at 10x (dermatoscopy) on micrographs of 62 histologically proven MN and 95 early MM (tumor thickness < 1 mm), which were random ly divided into a training and a test set. Multivariate analysis revea led that by combining the scores of four features (range in parenthese s) (Asymmetry )(0-2), Border (0-8), Colour (1-6), and Differential str ucture (1-5) (ABCD)) in a formula (A x 1.3 + B x 0.1 + Cx 0.5 + D x 0. 5 = Final dermatoscopy Score (FDS)), a diagnostic accuracy of 94%, spe cificity of 90.3%, and sensitivity of 100.0% could be achieved in the training set. With this ABCD rule of dermatoscopy, which can be easily learned and quickly calculated, a lesion is considered malignant, if the FDS exceeds 5.45. Reliability of the new ABCD rule was proven by a diagnostic accuracy of 92.2% and 97.9%, and specificity of 90.3% in t he test set.