The only effective treatment for melanoma is to remove it adequately whilst it is still localised to the primary site (most often the skin). It appears that there are several ways in which melanoma develops.
1. Some are quite slowly developing and occur usually as a new pigmented lesion or a change in an existing pigmented lesion. These are associated with intermittent sun exposure, and are more common in people with large numbers of moles or a family history of melanoma. They occur more often on the less sun exposed areas of the body especially the legs in women and back in men.This type is what most people understand as melanoma. Whilst usually brown to black in colour they may lack thesecolours and appear as flesh coloured, pink,grey or virtually any colour and or combination of colours. Provided these are detected when flat and thin the prospect of cure by simple removal is excellent.
Over the years the pneumonic “ABCD” (asymmetry, border irregularity, multiple colours and diameter greater than 6 mm) has been used to help the public identify suspicious pigmented skin lesions. Unfortunately a significant proportion of melanomas will be missed if these criteria alone are relied upon.
2. A second type occurs on chronically sun exposed skin especially of the head and neck, generally in older persons with high cumulative life time sun exposure, but without large numbers of moles or a family history of melanoma.
These are referred to as lentigo maligna, and sometimes develop from a Hutchinson’s melanotic freckle. These melanomas are slowing growing and generally curable by simple removal if detected for what they are and not neglected. Dermoscopy is especially
useful for differentiating these lesions
from common freckles and lentigos (sun freckles).
3. The third type is thick and fast growing, not clearly related to sun exposure at all, or to number of moles or family history.
These nodular melanomas can be very difficult to detect and often don’t show the usual ABCD’s. They account for the largest proportion of lethal melanomas. They can take on many different forms some of which are mistakenly presumed to be innocent and referred to as “melanoma incognito.” Because they grow rapidly are often quite thick right from the start there is significant risk that they may already have spread by the time they are detected and removed. It is critically important to find these melanomas early. Certainly any new spot or lump on the skin that has no obvious
cause and is not resolving over a few weeks requires evaluation by a doctor experience in the assessment of skin cancers. When any doubt exists as to the nature of the lesion a diagnostic biopsy is appropriate even though many of these thankfully will be negative for melanoma.
Melanoma prognosis is most directly linked to the thickness of the melanoma at the time of diagnosis, lesions less than 1 mm having cure rates in excess of 90% ( measured as patients surviving for 10 years after diagnosis).
