What is a pigmented skin lesion?

Congenital pigmented skin lesions are skin zones containing a higher concentration of superficially located pigment cells at birth, as compared to normal skin areas. These lesions are found in approximately 1% of all newborns. They are classified as follows according to the size of their largest diameter: small if less than 1.5 cm, medium if between 1.5 and 19.9 cm, and large if larger than 20 cm. Very large naevi are also known as giant naevi. These giant naevi form a special risk factor since they may show malignant degeneration throughout life (between 5 and 15%). If so occurs, the malignant degeneration develops already before the age of 10 in 70% of the cases. Because of this risk, large congenital naevi are removed preferably at young age.

Which treatment is appropriate and when?

If at birth a large skin zone with dark brown - almost black pigmentation (with or without hair formation) is observed, it is advised to treat this skin zone with curettage or dermabrasion before the baby is 10 days old. This is the most appropriate point in time, since these cells will migrate into deeper skin layers within 2 weeks after birth. Additionally, with increasing age these pigmented cells will also become more adherent to the skin. Consequently, this technique to reduce the amount of cells is only feasible in the early days of life. A large amount of pigmented cells can thus be surgically removed under general anesthesia. The resulting dermabraded wound will heal without scar formation within 10 days, if appropriately managed. During this period the child has to be hospitalized.

Unfortunately, some of the pigmented cells that are already deeper located can not be removed by means of this type of intervention. By consequence some pigmentation and the abnormal hair formation will left behind. Although the aesthetic appearance can be improved by the intervention, the risk of malignant degeneration remains and additional treatment at a later age is necessary. Indeed, in 2/3 of the cases in which malignant degeneration is found, it is found in deeper skin layers.

Final treatment

As soon the child has reached the age of 4 - 5 years, final surgical treatment under general anesthesia is possible. All layers of the affected skin need to be surgically removed with simultaneous reconstruction of this skin zone.

Reconstructive possibilities

  1. Serial excision.

    If the lesion is located at the extremities or the trunk, and the lesion is not too large, it can be removed in 2 or 3 stages. During the first stage, the center of the lesion is excised and wound margins can be reached because of skin elasticity. During the next stage(s) the outer margins will be removed. The final scar does have at least the length of the original lesion. Initially, the scar might widened. Therefore, a secondary correction at full grown age might be necessary. Bleeding, infection, or delayed wound healing rarely occurs during treatment, they may however influence the appearance of the final scar .

  2. Surgical removal of the affected skin and closure of the defect by means of transposition of local skin.

    The skin texture and color will match the original one, regrettably at the expense of additional scars in the surrounding areas. It will be tried, however, to place these scars in inconspicuous areas. Bleeding, infection, or delayed wound healing may sometimes occur during treatment. If so, secondary scar revision may be necessary.

  3. Surgical removal of the involved skin and closure of the defect by means of skin grafts.

    These skin grafts are preferably taken from an inconspicuous area. This technique will, however, not cause any new scars in the surrounding area. Five days after the intervention it can be seen if the grafts haven been taken. In order to prevent scar thickening of the graft compression, a treatment will be started four weeks after the intervention. This treatment will be maintained during a period of 1 year. In general results are good, although a slight skin color and texture difference with the surrounding healthy skin will be observed. The major risk of this intervention is that the graft will not be accepted due to infection or bleeding. If that is the case a second intervention is necessary. Sometimes extreme scar thickening at the margins of the grafts can be seen. Long-term compression therapy will then be needed.

  4. Tissue expansion.

    This technique implies at least 2 interventions. During the first intervention an expander is placed beneath adjacent healthy skin at the margins of the lesion. Three weeks later, or as soon as the wounds are healed, the expander will be weekly filled through a special device during three months. Consequently, the skin stretches progressively. As soon as size of the required volume has been obtained, the second intervention will take place. The involved skin zone is excised, the expander is removed, and the expanded skin is advanced to close the defect.

    Complications during the expansion period are the widening of the insertion scar and, in rare instances, wound formation with exposure and infection of the expander, which necessitates the premature removal of the expander.

Which treatment do you need?

Due to the large diversity of these lesions with respect to the location, the color, the size, texture and hair density, an individualized approach is needed. When choosing the most appropriate treatment your personal desires will be taken into account as much as possible.

What about laser treatment?

Skin resurfacing lasers, such as the CO2 laser, are principally not appropriate for the final management of these lesions since the lesions are evaporated using this technique. Consequently, tissue examination is impossible. Moreover, treatment of deepest skin layers cannot be done as healing will not occur. In contrast, aesthetic management of abnormal hair formation is possible if the rest pigmentation can be found. This is extremely exceptional, however.