Dermatoscopy of lentigo maligna.

Lentigo maligna and LMM require different dermatoscopic criteria for evaluation. The ease and accessibility of examining these lesions with dermatoscopy coupled with the clinical pathologic correlation afforded by the biopsy techniques discussed allow the practitioner to become proficient and prescient with the use of dermatoscopy. The criteria mentioned here are relatively new but are present and detectable in most cases of LM and LMM. The fact that there is some overlap among pigmented actinic keratosis, squamous cell carcinoma in situ, and lichenoid keratosis lesions should not detract or deter the physician from using dermatoscopy. Clinically, these lesions also usually will be equivocal and will require close clinical scrutiny and biopsies. If given the choice of using skin surface microscopy for one class of lesion only, one might well choose LM lesions because of their otherwise subtle nature and the clues that can be unlocked with oil immersion, illumination, and magnification, along with knowledge of these new criteria.