Pigmented moles

What are pigmented moles?

Pigmented moles are melanocytic naevi. The word ’melanocytic’ means thet they are made up of the cells (melanocytes) which produce the dark pigment (melanin) that gives the skin its colour. Melanocytes clustered together form naevi. This type of moles vary in colour in different skin tones and they are easier to see on pink skins.

Some moles are present at birth or appear within first two years of life are known as congenital melanocytic naevi. Most develop during childhood and early adult life and are consequently called acquired melanocytic naevi. The number of moles increase up to the age of 30-40. New moles appearing in adulthood need to be monitored and checked if growing or changing. Moles can be found enywhere on the skin, including ont he hands and feet, genitals, eyes and scalp.

What causes melanocytic naevi?

A tendency to have melanocytic naevi runs in some families. Sunburn or excessive sun exposure contribute to new moles formation and people with fair skin are more at risk.

What are the symptoms of melanocytic naevi?

Usually there are no symptoms as such. Raised moles may catch on things. Moles may become sore and inflammed after trauma.

What do melanocytic naevi look like?

Those that are present at birth (congenital melanocytic naevi) can be small (less than 1,5 cm in diameter), medium (1,2-20 cm) and large or giant (over 20 cm in diameter). Multiple giant congenital naevi have greater risk of developing melanoma.

There are three types of acquired melanocytic naevi:
• Junctional melanocytic naevi are flat, and usually circular. Their colour is usually even, and ranges from mid to dark brown.
• Compound melanocytic naevi are raised brown bumps, most of which are hairy. Some have a slightly warty surface.
• Intradermal melanocytic naevi are raised, often hairy, bumps, similar to compound naevi, but more pale coloured (often skin-coloured).

In childhood, most moles are of the junctional type (flat and usually circular). Later in life some become raised and more hairy, and moles on the face often become pale over time.

There are several other, less common, types of mole. These include:
• Blue naevus – a harmless mole with a dark blue colour.
• Halo naevus – a mole surrounded by a pale ring (compared to the skin) which may gradually go away by itself.
• Dysplastic or atypical naevi – these are usually multiple, with irregular pigmentation and shape, and run in some families. They have a greater tendency then most moles to change into melanoma, which is a skin cancer.

How will melanocytic naevi be diagnosed?

Most moles can be recognised easily by their appearance. A dermatologist may use an instrument called a dermatoscope to examine a mole closely. That device magnifies a mole (up to 20 times) and helps to examine it in more detail. It is a painless procedure. If there is any concern over the diagnosis your doctor will arrange for the mole to be removed and checked in the laboratory.

What is the risk of melanoma skin cancer with melanocytic naevi?

There is some risk of melanoma growing from an individual mole. However, there is a strong link between excessive or recurrent sun excposure and developing a melanoma from a normal looking skin.

Can melanocytic naevi be cured?

Yes. They can be removed surgically if necessary, but most are best left alone. There is a risk of developing a scar or a graft may be required for large moles excision. It is not recommended to have a mole removed with laser as it is not possible to have a sample for histology.

How can melanocytic naevi be treated?

There are three main reasons for removing moles:
• If there is a doubt about the diagnosis then the mole needs to be cut out and examined under the microscope.
• If the mole is traumatised on regular basis.
• Cosmetic reasons.

Self care (What can I do?)

If you have large number of moles:
Skin should be examined monthly for moles that are growing, or changing:
• in size (getting bigger)
• shape (becoming asymmetrical with an irregular ragged edge)
• colour (an uneven colour with different shades of black, brown or pink)

Also, if it has tendency to bleed, ooze or scab or if a mole is very different from the other moles on the skin.

If you have a concern about a mole or moles you should see your dermatologist as soon as possible.

Ask a family member or a friend to examine your back and taking a photograph is helpful to monitor any change to a mole.

Protect yourself and children from too much sun exposure. For example, be careful to avoid sunbathing and burning, cover yourself up and use sun protection creams of SPF 50. Do not use sunbeds.