Treatment of giant congenital melanocytic nevi with enzymatically separated epidermal sheet grafting

Treatment of giant congenital melanocytic nevi (GCMNs) must be considered from both a cosmetic and a medical aspect of reducing the risk of a growing malignancy. We treated five patients who had a GCMN on the trunk with an enzymatically separated epidermal sheet taken from their excised GCMN skin. All patients underwent enzymatically separated epidermal sheet grafting at the age of 2 months. With the patient under general anaesthesia, we removed the affected area with an electric dermatome until the brown colour had almost completely disappeared. The removed skin was immersed in dispase I solution (1000 U ml^-1) dissolved in Ringer's solution at 37 °C for 75-105 min until the epidermal sheet separated from the dermis without tension. Three back lesions and two abdominal lesions were treated. In all cases, the enzymatically separated epidermis grafted well, without infection. The amount of discharge that accumulated from immediately after the operation until the first dressing change (performed at 3 days after the operation) was reduced compared with that from curettage. The skin colour was light brown at first and gradually became lighter within a few months. The grafted areas were soft and did not show significant re-pigmentation. In most cases, hard hair did not grow on the treated area. Histological samples taken 1 year after the operation showed that the dermal layer was reconstituted without pigmented nevus cells. Enzymatically separated epidermal grafting is a useful method for the treatment of GCMN, is easy to perform and leaves cosmetically satisfactory results.