Clinical and Dermoscopic Features of Facial and Extrafacial Lentigo Maligna: A Case Series of 225 Lesions.

Abstract

Background: Lentigo maligna (LM) and its invasive counterpart, LM melanoma (LMM), are subtypes of melanoma associated with chronic sun exposure classically described in head and neck. Extrafacial LM is increasingly recognized and may display distinct dermoscopic features that facilitate earlier recognition than those of facial LM.

Objectives: To describe and compare the clinical and dermoscopic characteristics of LM and LMM on facial (head and neck) versus extrafacial sites in a large retrospective series from a tertiary center.

Methods: We conducted a retrospective, observational, single-center study including 225 histopathologically confirmed cases of LM or LMM diagnosed between 2017 and 2024. Demographic, clinical, dermoscopic, and histological features were collected and compared by anatomical site.

Results: Compared with extrafacial lesions, facial LM/LMM were diagnosed at an older age and more often presented as larger, polychromatic lesions with a higher frequency of blue-gray pigmentation on dermoscopy. Facial lesions also showed more regression-related structureless areas and rhomboidal structures. In contrast, extrafacial lesions more often displayed irregular pigmented foci and early features of reticular distortion, including parallel reticular lines, radial perifollicular lines, progressive loss of the reticular pattern, and an erased pigment network. Pink coloration was significantly associated with more invasive lesions, regardless of location.

Conclusions: LM and LMM demonstrate distinct dermoscopic patterns depending on anatomical site. Extrafacial LM are generally easier to recognize. Awareness of these site-specific differences may facilitate earlier clinical detection and improve dermoscopic interpretation across different body regions.