Moles (Melanocytic Naevi)

Introduction
The lay term for a melanocytic naevi is a “mole”.  The word ‘melanocytic’ means that they are made up of the cells (melanocytes) which produce the dark pigment (melanin) that gives the skin its normal colour.  Melanocytes cluster together to form naevi.  In other words, moles are localised and benign accumulations of melanocytes.  
Some moles (congenital melanocytic naevi) are present at birth: most come up later (acquired melanocytic naevi).  Most people have at least one acquired mole: many have several.  Some come up in early childhood, and others come up later, particularly during adolescence and pregnancy. 

What are the symptoms of melanocytic naevi?
Usually there are none.  Some moles look ugly: others catch on things.  Some become sore and inflamed after hairs have been plucked out from them. 

How can melanocytic naevi be treated?
There are three main reasons for removing moles:

1. The most important reason is doubt about the diagnosis. The mole then has to be checked under the microscope.  The main worry is usually whether or not the mole is really a melanoma.  The changes that suggest this include changes in size (getting bigger), shape (becoming asymmetrical with an irregular ragged edge) or colour (an uneven colour with different shades of black brown or pink).  Suggestive symptoms include itching and a tendency to bleed, ooze or crust up.  A good general rule is that small hairy moles seldom turn into melanomas.

2. The mole has become a nuisance by catching on clothing or being cut while shaving.

3. Cosmetic reasons. 
 
If there is any doubt about the diagnosis, the mole should be cut out completely under a local anaesthetic.  Other techniques can be used for moles being removed because they look ugly or have become a nuisance.  These include shaving the mole off flush with the skin (shave excision).