Medically reviewed by Dr. A.M. van Coevorden, dermatologist
Lentigo malignaa slowly changing pigment patch from sun damage, an early stage
A lentigo maligna, also called Dubreuilh's disease, is a patch of atypical pigment cells in the top layer of the skin, caused by long-term sun damage. The deeper skin layer is not yet affected. If the pigment cells grow into the deeper layer, it becomes a lentigo maligna melanoma, which can spread. That is why a lentigo maligna is always treated.
What is a lentigo maligna?
A lentigo maligna (or Dubreuilh's disease) is a patch of atypical pigment cells in the most superficial layer of the skin (epidermis); the deeper layer (dermis) is not affected. It occurs in 4 per 100,000 people a year, mainly in people over 60 on chronically sun-exposed skin. In a lentigo maligna melanoma the atypical pigment cells are also in the lower layer of the skin, so there is a chance of spread. The chance that a lentigo maligna becomes a lentigo maligna melanoma is unknown, estimated at about 5% over a lifetime. That is why a lentigo maligna is always treated.
How do you get a lentigo maligna?
The main cause is the sun, often long-term heavy sun exposure in the past, which damages the skin. People with fair skin are at greater risk than those with dark skin.
What symptoms does it cause?
A lentigo maligna often causes no symptoms such as pain or itch. It is usually a slowly enlarging patch, often present for years, that starts to change: the shape becomes irregular and the colour can be light to dark brown, grey or black. It usually sits on the face, on skin that has had a lot of sun.
Is a lentigo maligna contagious?
No. Lentigo maligna is not contagious.
How is the diagnosis made?
From the colour, shape and site the doctor may suspect a lentigo maligna, and can examine it more precisely with a dermatoscope (a special magnifier). The diagnosis is made with a biopsy: under local anaesthetic a piece of skin is removed and sent for examination.
What treatments are there?
Cutting out (excision) is the first choice: the patch is widely removed under local anaesthetic and the wound stitched, after which the pathologist checks that no lentigo maligna melanoma has developed in it. In a small proportion the lentigo maligna can return. At certain sites, especially the face, micrographically controlled surgery can be proposed, in which the margins are fully checked and as little healthy skin as possible is removed. Radiotherapy is a good treatment when excision is not possible because of size or site. The advice is to treat; in exceptional cases, in consultation, watchful waiting can be chosen.
Can a lentigo maligna be cured?
Yes, a lentigo maligna can be cured. It is, however, a sign of sun damage, so you are at risk of other precancers or skin cancer.
What can you do yourself?
Check your skin regularly. If you have a brown or black patch that changes or causes symptoms, take it to your GP or dermatologist. Avoid sunburn.
Frequently asked questions about lentigo maligna
Is a lentigo maligna skin cancer?
It is an early stage: atypical pigment cells in only the top layer of the skin. If they grow into the deeper layer it becomes a lentigo maligna melanoma, which can spread. That is why it is always treated.
How do I recognise it?
By a slowly changing patch, often on the face, with an irregular shape and brown, grey or black colour. Have a changing pigment patch assessed.
Can it spread?
A lentigo maligna itself cannot, as it is only in the top layer. A lentigo maligna melanoma, where the cells grow deeper, can. That is why treatment matters.
How is it treated?
Usually by wide excision, sometimes micrographic surgery on the face, or radiotherapy when excision is not possible.
Can it be cured?
Yes. It is a sign of sun damage, so skin checks and sun protection remain important.