Lentigo Maligna

General Information
Lentigo Maligna, also known Hutchinson’s Freckle is a type of malignant melanoma (skin cancer). Typically occurring on sun damaged skin in middle-aged and elderly patients, usually appearing on the face. Lentigo maligna (accounting for about 10% of cases diagnosed) is one of the four main subtypes of invasive melanoma, which include superficial spreading melanoma (accounting for about 70% of cases diagnosed), Nodular Melanoma (accounting for about 15% of cases diagnosed) and Acral Lentiginous melanoma (accounting for about 5% of cases diagnosed). The physical appearance of lentigo maligna begins as a spreading flat patch with irregular borders and different tones of brown. A health-care provider may evaluate the location of the Lentigo Maligna and progression as well as the general health of the patient prior to choosing a treatment. Nonsurgical procedures include cyrotherapy, radiation therapy, electro dissection, and curettage laser surgery; surgical procedures are based on the thickness of the tumor and the recommended clinical margin.

Epidemiology
Lentigo maligna melanoma is one of the four main subtypes of invasive melanoma and represents 5-15% of cases.

Etiology
Ultraviolet radiation exposure

Pathogenesis
Melanocytes invade the rich vascular and lymphatic networks of the dermis

Clinical
Lesion typically is tan-brown, with differing shades throughout

Histology
In earlier stages, merely hyperpigmentation on the basal cell layer is shown in some areas it may extend to the higher layers. In advanced stages basal melanocytes in the epidermis show marked increase in concentration, so that their number in some areas exceed that of basal keratinocytes.

Bibliography
1. “Lentigo Maligna Melanoma” (Online). December 2006. http://www.emedicine.com/med/topic1278.htm (visited: March 20, 2008)

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 Lentigo Maligna