Dermoscopic rainbow pattern in atypical fibroxanthoma.

why the pattern is found in other types of skin lesions with active vascularization, such as our patient’s scars. When first described in actinic keratosis, rosettes were characterized as ‘‘4 white points arranged as a 4-leaf clover.’’2 The sign has since been reported in other skin lesions such as squamous cell carcinoma, basal cell carcinoma, melanoma, and lichenoid keratosis.3--7 Rosettes are believed to be the result of an optical effect caused by interaction between polarized light and follicular openings.6 The rainbow pattern and rosettes are not considered to be specific dermoscopic features of the lesion. Since it appears that they are secondary effects of the interaction between different skin structures and polarized light, they will likely be observed in various types of skin lesions. References