Giant congenital melanocytic nevi of the trunk and an algorithm for treatment

Giant congenital melanocytic nevi (CMN) are rare, congenital, disfiguring lesions with a risk of degeneration to malignant melanoma. Giant CMN are associated with an increased risk of malignant degeneration. In a minority of cases, patients with giant CMN may have associated neurocutaneous melanosis with leptomeningeal involvement. Giant CMN of the trunk pose difficult diagnostic and reconstructive problems requiring complex multistage treatment. For high-risk cases, diagnostic evaluation in the form of neuro-imaging is an essential component of the planning phase. Although nonsurgical options for the treatment of giant CMN have been advocated, these modalities may decrease the burden of nevus cells but do not result in complete removal of these cells. The ability to monitor nevus cells that remain after nonsurgical management of giant CMN remains questionable. These nonsurgical options include dermabrasion, laser ablation, and chemical peel. In contrast, direct excision of the nevus is the mainstay of treatment of nonsurgical management of giant CMN. There are numerous surgical options to resurface the resultant cutaneous defect after excision of the nevus. The simplest of these options consists of serial excision and direct closure of the defect in stages. However, if the defect cannot be closed by direct cutaneous advancement, other options for wound resurfacing include split- or full-thickness skin graft, tissue expansion, and free tissue transfer. Tissue expansion should be viewed as a category of treatment options because expanders can be used to create an expanded full-thickness skin graft, local expanded flaps adjacent to the lesion, or expansion of a free tissue donor site. Given the diversity of reconstructive options that use tissue expansion, these techniques have evolved as the primary treatment method for giant CMN of the trunk. The authors outline an approach to the evaluation of giant CMN of the trunk, review the risks of melanoma and of neurocutaneous melanosis, describe their preferred treatment regimen, and offer a treatment algorithm for giant CMN of the trunk.