Understanding melanoma in situ and lentigo maligna

Understanding melanoma in situ and lentigo maligna

Introduction

This leaflet has been written to help you understand more about melanoma in situ and lentigo maligna. It will tell you what they are, what causes them, how they are treated and where you can find out more information.

You may need to ask your doctor or nurse for information that is more personal to you; please do not hesitate to ask any questions or voice any concerns that you, or your family may have, to your medical team.

What is melanoma in situ?

Melanoma in situ is the very earliest stage of a skin cancer called melanoma. ‘In situ’ means that the cancer cells have not had the opportunity to spread to anywhere else in the body, they remain in the top layer of the skin (the epidermis) and are all contained in the area in which they began to develop. They have not started to spread or grow into deeper layers of the skin and have not become invasive. Some doctors call melanoma in situ a pre cancer.

Melanoma in situ can be cured with surgery. However if not treated appropriately, melanoma in situ can develop into an invasive cancer called melanoma. It is therefore important to have it removed with a border of healthy skin (called an adequate surgical margin), there are also preventative measures you can take which will lower your risk of this condition occurring in the future.

What is lentigo maligna?

Lentigo maligna is a type of melanoma in situ. It is a slow growing lesion that appears in areas of skin that get a lot of sun exposure, such as the face or upper body. Because it grows slowly it can take years to develop. As with melanoma in situ, the cancer cells have not had the opportunity to spread to anywhere else in the body, they remain in the top layer of the skin (the epidermis) and are all contained in the area in which they began to develop. They have not started to spread or grow into deeper layers of the skin and have not become invasive. Like melanoma in situ some doctors call lentigo maligna a pre cancer.

Lentigo maligna can be cured with surgery. However, if not treated appropriately, lentigo maligna may later develop into an invasive cancer called lentigo maligna melanoma.

It is therefore important to have it removed with a rim of normal skin (called an adequate surgical margin), there are also preventative measures you can take which will lower your risk of this condition occurring in the future.

What causes melanoma in situ and lentigo maligna?

As both melanoma in situ and lentigo maligna are considered to be the earliest stage of a skin cancer called melanoma the following information discusses what causes this type of cancer. The most important cause is exposure to too much ultraviolet light in sunlight; this can include past episodes of severe sunburn, often with blisters, and particularly in childhood, intermittent episodes of sunburn as an adult, such as when on holiday and the use of sunbeds.

What are the risk factors for developing melanoma in situ and lentigo maligna?

• Past episodes of severe sunburn, often with blisters, particularly in childhood, increase the risk of developing melanoma. However, not all melanomas are due to sun exposure and some may appear in skin that is not usually exposed to the sun.
• People who burn easily in the sun are particularly at risk. Melanomas occur most often in fair-skinned people who tan poorly. Often, they have blond or red hair, blue or green eyes, and freckle easily.
• The risk is increased if another family member has had a melanoma. People who have already had one melanoma are at an increased risk of getting another one.
• Some people have many unusual (atypical) moles. They tend to be larger than ordinary moles, to be present in large numbers, and to have irregular edges or colour patterns. The tendency to have these moles can run in families and carries an increased risk of getting a melanoma. It is called the Atypical Mole Syndrome.
• People with many (more than 50) ordinary moles, or with very large (greater than 20cm in diameter) dark hairy birthmarks, have a slightly higher than average chance of developing a melanoma.
• People with a suppressed immune system (e.g. as a result of an HIV infection or taking immunosuppressive drugs, perhaps after an organ transplant) have an increased chance of developing a melanoma.

How is melanoma in situ and lentigo melanoma diagnosed?

If your doctor suspects that an unusual spot or mole may be a type of melanoma in situ or lentigo maligna, it is surgically removed and sent to a pathologist. This is called a biopsy or excision and is usually performed under local anaesthetic. A biopsy is essential for the diagnosis.

After the biopsy result is available your doctor will discuss with you the result and any treatment that will be necessary.

How is melanoma in situ and lentigo melanoma treated?

In all but a few instances, the treatment is simple surgery. A border of healthy skin from around the melanoma in situ or lentigo maligna is taken to make sure all abnormal cells are removed.

The wound will be covered with a dressing and follow up care will be organised. You may be uncomfortable for some days after your operation. If you have pain, paracetamol may be all you require.

Sometimes a skin graft may be necessary. This is more common for areas of the body that do not have much spare skin, for instance, the calf or face. A skin graft replaces the skin that has been removed with skin taken from another part of the body. If you have a skin graft, the area on which the skin is grafted may look unattractive after the operation, but eventually it will heal and the redness will fade. There is risk of infection, bruising and scarring after surgery. Occasionally the skin graft fails and needs further treatment.

Do I need any other treatment?

Surgery is the only treatment necessary for melanoma in situ and lentigo maligna in almost all cases.

Follow-up and checking yourself

The British Association of Dermatologists and other health organisations such as NICE (the National Institute for Health and Care Excellence) state that people who have had a melanoma in situ or lentigo maligna do not need any follow up visits with their specialist. This is because they are very unlikely to come back once they have been surgically removed.

Your specialist doctor or nurse should show you how to spot early skin changes in the future and how to protect yourself from the UV radiation from the sun.

Will I be cured?

The outlook, (prognosis), for melanoma in situ and lentigo maligna is excellent. It is very rare for them to come back because they were ‘in situ’, therefore they will not have had an opportunity to spread elsewhere in the body.

What can I do to help myself?

1. Learn how to spot skin changes early using the ABCDE rule and report any concerns to your doctor or nurse. You should be taught how to examine your own skin and be given an information leaflet.
2. Protect yourself and your family from sun damage. Stay out of the sun between the hours of 11:00 and 15:00. Slip on a shirt, a broad brimmed hat and sunglasses, apply a broad spectrum sunscreen that provides SPF of 30+ and a UVA star rating of 4/5, approximately 20 minutes before any sun exposure, reapply every two hours and minimise the time you spend in the direct sun. There are information leaflets for this too.
3. Adopt a healthy lifestyle: if you smoke, stop smoking. Ensure you get regular exercise, reduce your stress levels if possible and eat a healthy diet.

Vitamin D advice

The evidence relating to the health effects of serum Vitamin D levels, sunlight exposure and Vitamin D intake remains inconclusive. Avoiding all sunlight exposure if you suffer from light sensitivity, or to reduce the risk of melanoma and other skin cancers, may be associated with Vitamin D deficiency.

Individuals avoiding all sun exposure should consider having their serum Vitamin D measured. If levels are reduced or deficient they may wish to consider taking supplementary vitamin D3, 10- 25 micrograms per day, and increasing their intake of foods high in Vitamin D such as oily fish, eggs, meat, fortified margarines and cereals. Vitamin D3 supplements are widely available from health food shops. Advice and support It is completely normal not remembering what your doctor or the nursing staff tell you initially at diagnosis. For this reason we often say the same things to you a number of times. The skin cancer specialist nurses are here to go through the information in more detail and are a resource for all patients as and when needed. They can be contacted Monday to Friday on 01223 348156. If they are not available please leave a message with your name, date of birth and hospital number, if known and they will return your call. Vitamin D advice The evidence relating to the health effects of serum vitamin D levels, sunlight exposure and vitamin D intake remains inconclusive. Avoiding all sunlight exposure if you suffer from light sensitivity, or to reduce the risk of melanoma and other skin cancers, may be associated with vitamin D deficiency. Individuals avoiding all sun exposure should consider having their serum vitamin D measured. If levels are reduced or deficient they may wish to consider taking supplementary vitamin D3, 10-25 micrograms per day, and increasing their intake of foods high in vitamin D such as oily fish, eggs, meat, fortified margarines and cereals. Vitamin D3 supplements are widely available from health food shops.

Advice and support

It is completely normal not remembering what your doctor or the nursing staff tell you initially at diagnosis. For this reason we often say the same things to you a number of times. The skin cancer specialist nurses are here to go through the information in more detail and are a resource for all patients as and when needed. They can be contacted Monday to Friday on 01223 348156. If they are not available please leave a message with your name, date of birth and hospital number, if known and they will return your call.

Information on the Internet

• Macmillan Cancer Support (opens in a new tab)
• Cancer Research UK (opens in a new tab)
• British Association of Dermatology (opens in a new tab)
• SKCIN (opens in a new tab)