Lentigo Maligna

Lentigo maligna is a precursor of malignant melanoma, a form of in situ melanoma; common >40y, peak 70-80y. Yellow-brown/dark brown/black patches, irregular color, irregular border, centrifugal expansion, reticular pigmentation, hypopigmentation in regressed areas.

Common Symptoms

Freckle; macule; depigmentation

Causes and Pathogenesis

(1) Etiology: unknown; UV exposure is the key risk factor; lesions on chronically sun-damaged sites in middle-aged/elderly (face, neck, forearms). (2) Mechanism: epidermal atrophy, basal-layer atypical melanocytes non-nested proliferation, increased pigment; upper dermis lymphocytic infiltrate with melanophages; regressed areas show severe melanocyte degeneration, mild dermal fibrosis. When atypical melanocytes form nests/cords (spindle cells), it indicates in situ melanoma and predicts impending dermal invasion (invasive melanoma).

Treatment

Surgery, supportive therapy

Preventive Measures

Sun-exposed sites; protect skin in summer; early treatment of similar lesions.

Department to Visit

It is recommended to visit the Dermatology department; an appointment can be booked on this platform before the visit.

Warm reminder: The above information is for health science reference only and cannot replace professional medical diagnosis. If you have related symptoms, please seek medical attention at a regular hospital promptly.