Lentigo Maligna Melanoma

Excerpt

Lentigo maligna (LM) is a subtype of melanoma and commonly presents as an irregular brown macule on chronically sun-damaged skin, particularly the head and neck, in the elderly. It was first described by Hutchinson in 1890 and referred to as “Hutchinson’s melanotic freckle.” For much of the early 20th century, LM was thought to be either benign, infectious, or precancerous in nature due to its slow growth, with names given such as “junctional nevus,” “infective senile freckles,” and “circumscribed precancerous melanosis.” It was not until the late 1970s-80s, spearheaded by research by Silvers, Ackerman, and colleagues, that LM became widely recognized as malignant. Today, LM is defined as melanoma in situ (MIS) on chronically sun-damaged skin. Therefore by definition, LM is confined to the epidermis. If the lesion becomes invasive, it is termed lentigo maligna melanoma (LMM). Herein we review the key aspects of LM/LMM, as well as discuss the unique diagnostic and treatment challenges of this disease.