<p>A case of giant congenital melanocytic nevi is reported because of its unusually large size, cosmetic disfigurement and risk for malignant malformation.</p></sec><sec id="sec001"><title>Introduction

Giant congenital melanocytic nevi (GCMN) are rare nevi (> 20 cm in diameter) with a reported incidence of 1 in 20,0001. Usually occupying large areas of the body surface, they are at increased risk for developing malignant melanoma. We report here a neonate with GCMN because of its unusually large size.

Case report

A full-term male weighing 3.3 kg born to a 32-year-old fourth gravida mother after an uneventful pregnancy, labor and delivery presented with an extensive pigmented patch covering large areas of the lower trunk. There was no history of consanguinity. Family history was non-contributory.

Examination revealed a large, firm, lobulated and deeply pigmented mass (34 cm across) over both buttocks, lower back, groin, upper thigh and lower abdomen with scattered black hair (Fig. 1 and 2). Multiple small deeply pigmented satellite lesions were also seen over the rest of the body surface. No other associated congenital anomalies were observed. Neurological and other systemic examinations were normal. Fundus examination, X-ray spine and USG of cranium were normal. Histopatholoical findings of the skin biopsy were consistent with CMN (compound type). Fig. 1Neonate with GCMN involving “bathing-trunk” area.

Fig. 2Neonate with GCMN involving “bathing-trunk” area.

Discussion

Congenital melanocytic nevi (CMN), found in 1% of the newborns, are classified depending on their size, as small (1–1.5 cm), intermediate (1.5 – 20 cm) and giant (> 20 cm)2. They occur as raised verrucose or lobulated nodules or plaques of varying shades of brown to black, sometimes with blue or pink components. The giant variety also known as giant hairy nevus or “bathing-trunk” nevus most often occur in a ‘garment ’ distribution on the trunk and adjacent limbs. A tendency to follow a dermatome distribution results in typical picture in most cases as observed in our case. Histologically, giant nevus may have several components, nevus cell, neuroid nevus and dermal melanocytic type nevus such as blue nevus and cellular blue nevus may be present singly or combined.

Congenital anomalies associated with GCMN are spina bifida or meningocele when the nevus is over the vertebral column or club foot and hypertrophy or atrophy of deeper structures of a Iimb3. These associated anomalies were not observed in our case. Although our case belongs to the common variety, such an extensive, large, lobulated and deeply infiltrative lesion has not been reported in Indian literature. We feel that such a case runs a significant risk of developing malignant melanoma. The lifetime risk of developing malignant melanoma in GCMN is 4 –6%4. Fifty percent of malignant transformations occur by age 5 yr1. GCMN involving the scalp and neck may be associated with leptomeningeal melanocytosis causing hydrocephalus, seizures, retardation and motor deficits and may result in melanomas5.

Surgically, GCMN are a challenging problem. Giant nevi are often removed because of the increased incidence of malignant transformation and cosmetic disfigurement. The treatment of choice is total excision and repair aided by tissue expander or grafting which should be done early in life because of the high risk of malignant degeneration during childhood. Dermabrasion has also been successfully employed with satisfactory cosmetic results but the procedure leaves behind nevus cells in the deep dermis, and the malignant risk is not substantially reduced5. In view of the large size, extensive involvement psychological trauma to the parents. Parents were counseled about the nature of the lesion and advised regular follow up. Unfortunately, we cannot discuss the subsequent course, as the child was lost to follow up.

of the skin, no active management was considered in our case. Surgical intervention in our case would have definitely left behind lots of scarring, cosmetic disfigurement and psychological trauma to the parents. Parents were counseled about the nature of the lesion and advised regular follow up. Unfortunately, we cannot discuss the subsequent course, as the child was lost to follow up. of the skin, no active management was considered in our case. Surgical intervention in our case would have definitely left behind lots of scarring, cosmetic disfigurement and