[Effect of dermoscopy on diagnostic accuracy of pigmented skin lesions emphasizing malignant melanoma]

Abstract

Background: Skin tumors are the most common malignancies in the Western population, with surgical excision being the definitive treatment.

Objectives: The authors' objectives were to compare the precision of clinical diagnosis of malignant melanomas (MM) by a plastic surgeon in a community clinic with and without the use of dermoscopy.

Methods: The control group comprised of all patients operated on solely by one plastic surgeon between 2001 and 2003, at which time dermoscopy was not used. The study group included all patients operated on by the same surgeon between the years 2007 and 2008. Clinical, dermoscopic and histological data for both groups were reviewed. The sensitivity and positive predictive value (PPV) were measured and compared using the Fisher's exact test and chi square test.

Results: Overall, 1806 skin lesions were excised in the control group compared to 1039 lesions in the study group. A total of 680 melanocytic lesions, 167 dysplastic melanocytic lesions and 20 MM were excised in the control group. The sensitivity for the diagnosis of melanoma was 80% and the PPV was 53%. In the study group 415 melanocytic lesions where excised, of which 63 were dysplastic lesions and 14 MM. The sensitivity for MM diagnosis was 77% and the PPV was 83%. The authors found a statistically significant improvement in the positive predictive value (P<0.05), however, no significant change in the sensitivity for MM diagnosis was observed. A significant statistical reduction in the removal of dysplastic melanocytic lesions was also observed (P<0.05).

Conclusions: Dermoscopy is a simple, easy to use technique which aids the clinician in improving his accuracy of melanoma and dysplastic melanocytic lesions diagnosis thus reducing unnecessary benign excisions.