Modified ABC-point list of dermoscopy: A simplified and highly accurate dermoscopic algorithm for the diagnosis of cutaneous melanocytic lesions.
BACKGROUND
The use of dermoscopy (epiluminescence microscopy, surface microscopy, dermatoscopy) improves clinical diagnostic sensitivity by 10% to 27%, particularly achieved by different algorithms or scores.


OBJECTIVE
We sought to develop a simplified and highly accurate dermoscopic-point list for cutaneous melanocytic lesions.


METHODS
We studied consecutive patients with suspicious melanocytic lesions, which were excised and histopathologically examined at our institution. On the basis of the ABCD rule of Stolz, Menzies score, and the modified ABCD rule of Kittler, a simplified ABC-point list was developed. Simple points were given for the following: asymmetry of outer shape (A) or differential structures inside the lesion in at least 1 axis ((A)); the abrupt cutoff of network at the border in at least one quarter of circumference (B); 3 or more colors (C); 3 or more differential structures (D); or noticed change (evolution) in the last 3 months (E). Using 20-fold magnification of computer dermoscopy, the sensitivity, specificity, and diagnostic accuracy were examined in 269 cutaneous melanocytic lesions. Of these, 84 (31.2%) were cutaneous melanomas. Also, the sensitivity, specificity, and diagnostic accuracy were investigated with a 7-point checklist and the 7 features for melanoma.


RESULTS
With the ABC-point list for the diagnosis of cutaneous melanoma, sensitivity was 90.5%, specificity was 87%, and diagnostic accuracy was 88.1%, confirmed by cross-validation. The ABCD rule resulted in 90.5%, 72.4%, and 78.1%; Menzies score in 95.2%, 77.8%, and 83.3%; 7-point checklist in 90.5%, 87%, and 88.1%; and 7 features for melanoma in 94%, 74.6%, and 80.7%, respectively,


CONCLUSIONS
The ABC-point list is simpler than the already established algorithms. Despite its simplicity, a high sensitivity, specificity, and diagnostic accuracy was achieved. This simplified approach in dermoscopic diagnostics may contribute to further spread and enable to learn and use this method more easily.
Department of Dermatology, University of Tuebingen, Germany. a.blum@derma.de
Andreas
A
Blum
Gernot
G
Rassner
Claus
C
Garbe
D000465:Algorithms; D005260:Female; D017408:Guidelines as Topic; D006801:Humans; D008297:Male; D008545:Melanoma / Q000175:diagnosis* / Q000473:pathology*; D008853:Microscopy / Q000379:methods*; D015588:Observer Variation; D010781:Photography; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D012878:Skin Neoplasms / Q000175:diagnosis* / Q000473:pathology*