A Case Report of a Comparative Approach in a Patient with Multiple Seborrheic Keratosis: Does It Work for SK-Like Melanoma Screening?

SK is a common benign tumor that can mimic melanoma, complicating diagnosis. The originality of this case lies in applying the ugly duckling sign -typically used to assess nevi - to multiple SK lesions. This comparative approach enabled the identification of a single atypical lesion, ultimately diagnosed as melanoma in situ. In patients with numerous SK, extending the use of this method beyond nevi may help detect malignant lesions that would otherwise remain unnoticed.