Pitfalls in the clinical and dermoscopic diagnosis of pigmented actinic keratosis.

Pigmented actinic keratosis and melanoma may exhibit overlapping clinical features, thus representing a diagnostic challenge for dermatologists. Although the differentiation between these two entities is traditionally done by histopathology, dermoscopy has been utilized as a useful additional aid for improving the clinical diagnostic accuracy of such pigmented skin lesions. We report the clinical and dermoscopic features of two pigmented actinic keratoses to discuss the difficulties in their preoperative differential diagnosis.