The dermatoscopic ABCD rule does not improve diagnostic accuracy of malignant melanoma

The dermatoscopic ABCD rule has been suggested to improve diagnostic perfor mance regarding cutaneous malignant melanoma. Using this rule, a total derm atoscopy score is calculated from the presence of various dermatoscopic ele ments. A total dermatoscopy score above 4.75 signifies possible melanoma. W e compared the diagnostic accuracy of dermatoscopy with and without the use of the ABCD rule. Furthermore, receiver operating characteristic analysis was performed for the ABCD rule. The area under the receiver operating char acteristic curve was 0.854 (range 0.777-0.906) demonstrating that in 85.4% of the cases, cutaneous malignant melanomas were rated higher than the non- melanoma skin lesions. Sensitivity for the melanoma diagnosis was higher fo r simple dermatoscopy than when the ABCD rule was used (p < 0.05). There wa s no difference in specificity when a total dermatoscopy score of 4.75 was used as cut-off point, but specificity was lower for simple dermatoscopy th an when the total dermatoscopy score of 5.45 was used. Diagnostic accuracy was higher for simple dermatoscopy than for the ABCD rule (p < 0.01). In co nclusion, the dermatoscopic ABCD rule was not superior to simple dermatosco py, and fewer malignant melanomas were identified with this rule.