Dermoscopic evaluation of pigmented skin lesions with the "chaos and clues" algorithm: Basal cell carcinoma and melanoma

(A) Basal cell carcinoma demonstrating "chaos," defined as the asymmetric distribution of dermoscopic structures or colors.
(B) Using the chaos and clues algorithm, this lesion does not demonstrate "chaos." However, it reveals two of the eight "clues" for malignancy, including gray or blue structures and reticular white lines (also known as negative network). Thus, the lesion is considered suspicious and a biopsy should be performed. Histopathologic examination demonstrated a spitzoid melanoma.