Lentigo Maligna

Synonyms

Hutchinson melanotic freckle; lentigo maligna melanoma in situ.

Epidemiology

10-15% of all melanoma. Slight female predominance.

Definition

Intraepithelial proliferation of atypical melanocytes mostly in sun-damaged skin and in elderly patients.

Aetiology & Pathogenesis

Chronic natural and artificial UV exposure.

Signs & Symptoms

Irregularly pigmented macule or patch with irregular borders, not palpable, slow growing.

Localisation

Sun-exposed areas (face and neck area, forearms, shins).

Classification

In situ melanocytic proliferation.

Laboratory & other workups

Not necessary.

Dermatopathology

Epidermal atrophy, increased number of atypical melanocytes in basal layer, also extending into hair follicle, dermal lymphocytic infiltrate, melanophages, solar elastosis.

Course

Lesions slowly extending and finally developing into a lentigo maligna melanoma.

Complications

Lentigo maligna melanoma and metastasis.

Diagnosis

Clinical features and histology.

Differential diagnosis

Lentigo simplex, solar lentigo, flat seborrhoeic keratoses, melanoma (lentigo maligna melanoma, superficial spreading melanoma Level 1), naevoid lentigo, atypical naevi.

Prevention & Therapy

Depends on the size and location. Excision is preferred. If excision is not possible or otherwise contraindicated, soft X-ray treatment.

Special

Patients should be diagnosed and treated in experienced dermatological settings.

3.3.6 Lentigo Maligna