Lentigo Maligna Flashcards
What is lentigo maligna?
A slow-growing, in situ melanoma that develops in sun-damaged skin, commonly on the face or other chronically sun-exposed areas.
What is lentigo maligna melanoma (LMM)?
The invasive form of lentigo maligna, occurring when melanoma cells invade the dermis.
How does lentigo maligna differ from other melanomas?
It has a prolonged radial growth phase, remaining non-invasive for years before becoming invasive.
What population is most commonly affected by lentigo maligna?
Older adults (peak incidence in people >60 years).
Fair-skinned individuals with significant cumulative sun exposure.
What are the primary risk factors for lentigo maligna?
Chronic sun exposure, particularly in older adults.
Fair skin (Fitzpatrick skin types I and II).
History of actinic damage or other skin cancers.
Family or personal history of melanoma.
What causes lentigo maligna?
Accumulated DNA damage from ultraviolet (UV) radiation leads to mutations in melanocytes, resulting in uncontrolled growth.
What are the key clinical features of lentigo maligna?
Asymmetrical, flat, pigmented macule or patch.
Irregular borders and variegated pigmentation (shades of brown, black, gray).
Typically appears on sun-damaged areas, such as the face, scalp, and neck.
What is the Hutchinson’s sign in lentigo maligna?
Extension of pigmentation into adnexal structures (e.g., hair follicles), often indicating deeper involvement.
How is lentigo maligna diagnosed?
Dermatoscopy: Shows asymmetry, irregular pigment networks, and rhomboidal structures.
Skin biopsy: Confirms the diagnosis; histology reveals atypical melanocytes along the basal layer.
What is the gold standard treatment for lentigo maligna?
Surgical excision with histological margin control, such as Mohs micrographic surgery.
Why is Mohs micrographic surgery preferred for lentigo maligna?
It ensures complete tumor removal while preserving as much healthy tissue as possible, particularly in cosmetically sensitive areas like the face.
What are non-surgical treatment options for lentigo maligna?
Topical imiquimod: An immune response modifier for non-surgical candidates.
Radiation therapy: For elderly or inoperable patients.
Are cryotherapy or laser treatments effective for lentigo maligna?
No, these treatments are not recommended as they may leave residual tumor cells.
