Giant Congenital Melanocytic Nevus : About a Case

Giant congenital melanocytic nevi (GCMN) are a rare occurrence. They arise from mutations in either BRAF or NRAS genes. The major complications associated with GCMN are malignant melanoma and neurocutaneous melanosis. Management of GCMN is symptomatic. We present a rare case of a 20-year-old woman born with GCMN.


Introduction
Congenital melanocytic nevi (CMN) are large brownto-black skin lesions caused due to genetic mutations which leads to abnormal proliferation of embryonic melanoblasts [1,2].Besides malignant transformation, patients with GCMN need to be periodically assessed for neurological abnormalities and psychosocial impairment.We present a rare case of a 20-year-old woman with GCMN, discussing its etiology and latest trends in management.

Case Report
The patient is a 20-year-old woman who consulted for several pigmented patches over her body.The parents of the patient did not have a consanguineous marriage.None of the close family members had similar skin lesions.On examination, an extensive pigmented nevus was observed encompassing the neck, the back, the breast and the arms.Numerous smaller satellite sure (200 MPa for 10 min) and replanting it to its original site [6].The use of an NRAS inhibitor (trametinib) is proposed for treating patients with an underlying NRAS mutation [1,2].Use of endothelin-1 receptor antagonists has also been proposed.However, more clinical trials with larger samples size and longer follow-up periods are needed to determine the success rate of these techniques.

Conclusion
GCMN, although a rare condition, is associated with severe life-threatening complications such as malignant melanoma and NCM.Management includes surgical and non-surgical procedures, psychological intervention and clinical follow-up.
CMN are characterized by their projected adult size, number of smaller satellite lesions, anatomical localization, and degree of rugosity, hypertrichosis, nodularity, and color heterogeneity [5].A nevus with a projected adult size greater than 40 cm is classified as GCMN, as in our case.GCMN are further classified into six categories according to their anatomical location as bolero, back, bathing-trunk, breast/belly, body extremity, and body [5].Our patient belonged to the bolero category.
Management of GCMN is symptomatic and palliative.Surgical techniques include serial resection, excision followed by skin grafts/substitutes, and use of tissue expanders followed by resection [2,3].Nonexcisional techniques for GCMN include dermabrasion, laser ablation, curettage, and chemical peel [3].A novel surgical technique showing promising results is full-thickness excision of the nevus tissue, followed by its inactivation by high hydrostatic pres-

Figure 1 :
Figure 1: Giant melanocytic nevus encompassing the back and the neck.Numerous smaller satellite nevi are observed on the gluteal region.

Figure 2 :
Figure 2: Giant melanocytic nevus involving the breast with smaller satellite nevi on the abdomen.

Figure 3 :
Figure 3: Extension of a giant melanocytic nevus to the neck with smaller satellite nevi on the face.