[Clinical value of a dermatoscopic classification of Clark nevi]

Abstract

Background and objectives: The aim of this study was to evaluate the practical value of the dermatoscopic classification of Clark nevi

Patients and methods: Dermatoscopic images of 268 lesions clinically and dermatoscopically diagnosed as Clark nevi were presented to 2 dermatologists without knowledge of the histological diagnosis. The dermatologists evaluated the lesions according to a simplified version of the classification scheme for Clark nevi proposed by Hofmann-Wellenhof and differentiated between 12 different types of Clark nevi.

Results: The most common type of Clark nevus was the reticular-homogenous type (n = 64, 23.9%), followed by the globular-homogeneous type (n = 32, 12%) and by the homogenous type (n = 30, 11.2%). The overall inter-rater agreement between the examiners was moderate to good (kappa = 0.58). The highest level of agreement was found for the peripheral hyperpigmented type (kappa = 0.83). Histologically, 17 lesions (6.3%) were diagnosed as melanomas. The frequency of melanoma was highest among the peripheral-hyperpigmented type for one observer and among the homogenous type for the other observer. No melanoma was found among the globular, reticular-globular, and the central-hyperpigmented types.

Conclusions: A dermatoscopic classification of Clark nevi is practically feasible and allows--to some extent--a risk stratification of Clark nevi, which could be useful for clinical management.