DOI: 10.7241/ourd.20122.31                                                                   article in PDF
Our Dermatol Online. 2012; 3(2): 138-139
Date of submission: 05.01.2012 / acceptance: 25.01.2012
Conflicts of interest: None
 

GIANT CONGENITAL MELANOCYTIC NEVUS ON THE BACK

Husein Husein El Ahmed, Jose Carlos Ruiz Carrascosa

Department of Dermatology, San Cecilio University Hospital, Granada, Spain

Corresponding author: Dr. Husein Husein El Ahmed    e-mail:huseinelahmed@hotmail.com

How to cite an article: El Ahmed HH, Ruiz Carrascosa JC. Giant congenital melanocytic nevus on the back. Our Dermatol Online 2012; 3(2): 138-139.

 
Sir,
Congenital melanocytic nevi (CMN) are pigmented lesions appearing in the birth or after few days of birth. CMN are clasified as giant when the surface diameter is ≥ 20 cm [1]. Giant CMN are less frequent than small nevi, but show a significant higher risk of developing melanoma and neurocutaneous melanocytosis [2,3]. We present an outstanding case of giant CMN in woman located on the back. A 47-year-old woman presented with a pigmented plaque on her back, which was present since birth and had gradually increased to the present size. This condition had a psychological and social impact in our patient during her childhood, since she tended to avoid situations in which she had to undress, such as swimming and sports. However parents declined excisions. At age of 47, she was referred to our department of dermatology for assessment. The growth of the nevus discontinued at age of 20 and since then no other changes in shape, color or thickening were observed. Clinical examination revealed a huge (43X38 cm), hairy, brown-black congenital melanocytic nevus involving the neck and the upper back (Fig. 1). Magnetic resonance imaging of the brain was negative for melanosis and thickening of leptomeninges. Findings on the dermatoscopy revealed areas with globular and homogeneous pattern, brown and black dots and globules, small milia-like cysts and terminal hairs. After considering the benign clinical and dermatoscopic outcomes and the risk of inaesthetic result with the surgical remove of this large lesion, a conservative approach was decided. Giant CNM occur in approximately 1 of 20000 newborns in Caucasion population [4]. The etiology of CNM is caused by a morphogenic error in the neuroectoderm leading to a dysregulated growth of melanoblasts during the 5th and 24th weeks of gestation [5]. The importance of CNM lies in the fact that these lesions may be precursors of malignant melanoma, particulary those large lesions (≥ 20 cm) which shows a lifetime risk of melanoma between 4.5% and 10% [6]. Early evaluation and surgical removals of large CNM are indicated not only because of the high potential of degeneration to a melanoma, but also due to the aesthetic impact of these conditions. However, the management should be individualized in each patient considering the location and size of the nevus, the psychosocial impact, the risk of surgery and the cosmetic issues related to the surgical scar. In our patient, although the psychosocial impact of giant nevi was considerable, the lack of dermatoscopic malignant signs as well as the cosmetic issues related of the huge size of the lesion resulted in a conservative management. When removal of giant atypical CNM is decided, it should be performed in early stages to avoid large and excessive scar: the surgical challenge is the functional and aesthetic reconstruction. A staged excision and use of tissue-expander or an intermeadiate-thickness skin graft are usually required in giant CNM. In our patient, serial examination with dermatoscopy are performed periodically with no signs of malignant transformation during the follow-up.
 
Figure 1. Giant congenital melanocytic nevus involving neck and upper back
 
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