Pigmented moles (Naevus pigmentosa) may appear at birth or are acquired later, may be small or very large (possibly covering entire body areas), may be uniformly or unevenly pigmented, may be static or may change in some of their characteristics – any or all of these aspects will determine the appropriate course of action. The change in the composition of solar radiation and the statistical increase in the occurrence of malignant melanoma have caused an increased awareness of the risks and are clear warnings that protection is essential.
Morbidity due to melanoma is on the rise worldwide; in Hungary, this statistic was 15/100,000 in 2006. Moderate female dominance is observed, with the average age being 52, but the number of patients has significantly grown in the 20-30 year age group. Occurrence in children is very rare, and the increase in morbidity is lower than for adults (only a few cases have been noted in Hungary).
These data point to the significance of examining the relationship between the appearance of pigmented moles and exposure to sunlight. Pigmented moles are monitored from birth into the teenage years, different courses of action being appropriate for each age group.
Congenital pigmented moles appear at birth. If there are only a few brown moles and their diameter does not exceed 1-2 mm, they need only be noted. If the diameter of the mole is larger than 2 cm or covers a larger area, is thickened, darkly pigmented, or hairy, parental concern is understandable, the effect is aesthetically unpleasant. There is a risk that these are associated with Neurocutan melancytosis, which is the mutation of the membranes of the nervous system, i.e., there is an increased occurrence in melanomas derived fro the dermal component. Total removal should be the objective, with a strategy to be developed in the first days of life, taking into consideration the optimal surgical technique, timing and the overall health of the infant, as well as the risk of anesthesia. Until then, close observation is essential.
The next age group is 6-10 years of age, when the parents or the school physician may note a somewhat increased number of moles. These moles should be assessed by number, the time of their appearance and their characteristics. Those which are abnormal in any way should be photographed digitally so that there is a basis for comparison with later photographs.
If the number of moles exceeds 50, a regular annual screening examination is required, in addition to parental monitoring.
Dysplasius naevus, whose clinical signs are variable, cannot always be reliably diagnosed by dermatoscope.
Numerous, atypical naevus pigmentosus (dysplasticus naevus syndrome) requires a special assessment. These often exceed 300 in number, which makes individual monitoring virtually impossible. Half-yearly monitoring is required, with serial photography of the most unusual moles. There is usually some form of regularity observable in dysplasia – those moles which differ from the “rule” require special monitoring or removal. For example, if all the dysplastic moles are medium brown, evenly pigmented, have irregular edges and a smooth surface, then an “ugly duckling” which is darkly pigmented with a bumpy surface and is wartlike in appearance should be removed, especially if it has recently developed.
The existence of numerous pigmented moles can be considered to be a marker, i.e., multiplex dysplastic naevus indicates an increased predisposition to melanoma.
The blue naevus is a dermal melanocyte cluster which can be present at birth, but most often appears in childhood. They can occur in multiplex, as part of the syndrome. Their removal is necessary because it is difficult to assess the condition of the pigment in the deep layers of the epidermis.
Pigmented moles often increase in number or change during puberty, in connection with hormonal changes. The appearance of Sutton or halo-naevi – which are surrounded by a characteristic white “halo” - indicate an immunological process which is related to regression in melanoma. Excision of the closely observed, halo naevus is unnecessary if symmetry of shape is maintained.
Adolescents often indicate their desire to have a mole removed due to fear or for aesthetic reasons. It is important to inform the patient that moles cannot be removed without leaving a permanent scar, while the existence on the skin of a trouble-free mole is normal. These requests, however, should be dealt with sensitively as excessive concern is psychologically stressful.
A variety of melanocytas naevus is the spindle-shaped Spitz naevus, which suddenly appears in early childhood and which is also referred to as juvenilis melanoma for histological purposes. Meyerson naevus is a junctional or compound naevus which is surrounded by an excematoid reaction. Naevus spilus usually begins as a single pigmented stain at birth; years later, however, characteristic dark spots appear in the light brown stain.
Among exogenous factors, intensive sunlight causing intermittent, severe, blistering burns is significant. Exposure to sunlight increases the number of moles, this in turn increases the occurrence of melanoma.
The likely cause is that melanocytes lose their normal ability to die off in response to strong sunlight, resulting in proliferation of melanocyte clones with altered DNA. Among adults, 30% of all melanomas evolve from naevi, this percentage is 50% among children. Melanoma rarely develops from small, congenital or acquired moles, while 20% of very large (more than 20 cm), congenital naevi leads to the disease; in these cases, melanoma generally develops on the skin, but 2-4% of cases develop on mucous membranes, or the membranes that cover the brain (meningeal) or the eye (uvealis).
Although damage to skin due to sunlight appears earlier and earlier in children, it is still relatively rare. Patients therefore understandably have difficulty in comprehending that only early prevention is effective. The situation is complicated by the fact that young children are dependent on their parents for the care of their skin, for the health of the next generation. Misinformation, relatively few truly alarming experiences in the past and the underestimation of the severity of the problem can only be countered with thorough medical attention and patient information. Training can begin in preschool to create awareness of the dangers and to demonstrate safe methods of sunbathing.
Screening involves a survey of the entire body surface, the careful examination of suspicious growths, the tracking of these with photographic documentation to the extent possible and a recommendation for removal, if necessary.