Role of Dermoscopy

Abstract

Lentigo maligna (LM)/lentigo maligna melanoma (LMM) typically presents as an isolated pigmented macule or patch on chronically sun damaged skin. At early stages in its clinical presentation the appearance of LM/LMM overlaps with solar lentigo, macular seborrheic keratosis, pigmented actinic keratosis, and lichen planus-like keratosis. Consequently, LMM diagnosis is often delayed or unnecessary biopsies of the aforementioned benign entities are frequently performed. Use of dermoscopy, however, improves diagnostic accuracy for LMM and limits biopsies of its benign simulators. Common dermoscopic features associated with LMM include the presence of asymmetrically pigmented or gray-colored follicular openings and peri-follicular grey dots/granules, which produce the so-called “annular-granular pattern. In addition, LMM can have angulated pigmented lines that join to create zigzag lines or polygonal structures such as rhomboids. In addition to helping with the primary diagnosis of LMM, dermoscopy is used to optimize biopsy site selection, to select treatment margins, and to identify potential recurrence during post-treatment monitoring.