Malignant transformation in congenital sebaceous naevi in childhood.

Sebaceous naevi are uncommon congenital skin lesions with a well-recognised potential for neoplastic change. They should be considered premalignant lesions as malignant degeneration, most commonly basal cell carcinoma and squamous cell carcinoma, occurs with a lifetime risk of between 5% and 22%. This incidence is equal to that of actinic keratosis and exceeds that of oral leukoplakia. Such change, however, is rare before puberty. Basal cell carcinoma may develop in children with naevoid basal cell carcinoma syndrome, xeroderma pigmentosum and rarely de novo but sebaceous naevus is the only solitary lesion in childhood associated with the development of basal cell carcinoma. We present two cases of malignant transformation in a congenital sebaceous naevus occurring in childhood and review the literature and discuss the evidence upon which to base management guidelines.