Giant congenital nevus with progressive sclerodermoid reaction in a newborn

Giant congenital melanocytic nevi are a rare occurrence in the pediatric po pulation. The risk of malignant transformation associated with these lesion s has been well established; however, the management strategies for giant c ongenital nevi remain controversial. We report an unusual sclerodermoid rea ction in a giant congenital nevus in a 6-week-old Caucasian girl. Given its abnormal clinical appearance, the entire lesion was excised. The histology was consistent with an atypical compound/sclerosing spindle and epithelioi d cell congenital nevus. No evidence of malignant change was seen histologi cally. The incidence of malignant transformation in giant congenital nevi h as been difficult to calculate. Review of the literature yields an incidenc e of between 4 and 9%, favoring surgical excision of these lesions where po ssible. Atypical presentations of giant congenital nevi are rare, and we ha ve found no other reported cases with a stromal change similar to that seen in our patient. We hypothesize that this change may represent an atypical host reaction to the nevus cells.