Comparison of two dermoscopic techniques in the diagnosis of clinically atypical pigmented skin lesions and melanoma: seven-point and three-point checklists.

Background: Over the past decade, many dermoscopic criteria and algorithmic methods have been developed for the early diagnosis of cutaneous melanoma.

Objective: To compare the sensitivity, specificity, and diagnostic accuracy of the seven-point and three-point checklist methods in a series of dermoscopic images. The diagnostic value of dermoscopic criteria was also determined on the basis of their frequency.

Methods: Forty-eight preoperative dermoscopic images of histopathologically proven melanoma lesions and 48 preoperative dermoscopic images of clinically atypical but histopathologically proven nonmelanoma pigmented skin lesions were reviewed retrospectively. The seven-point and three-point checklist methods were used to assess each lesion. The Statistical Package for Social Sciences for Windows 15.0, descriptive statistical tests, and screening tests were used for statistical analyses.

Results: The sensitivity, specificity, and positive and negative predictive values of the seven-point checklist method were 87.50%, 16.17%, 51.22%, and 57.14%, respectively. The sensitivity, specificity, and positive and negative predictive values of the three-point checklist method were 89.58%, 31.25%, 56.58%, and 75%, respectively.

Conclusion: The three-point checklist was observed to be a superior screening test. The seven-point checklist provided a more detailed analysis, especially for thin melanomas. In comparison with the seven-point method, the three-point method may be useful for less experienced observers when they need to obtain greater diagnostic accuracy.