The most common malignant tumor derived from NS is basal-cell carcinoma (BCC), revealing that NS and BCC share deletions of the PTCH tumor suppressor gene on chromosome 9q22.3.[3,4] Reported incidence of malignant transformation to BCC varies from 0.8 to 22%.[5–7] Therefore, when surgeons encounter patients with NS, they should determine whether prophylactic excision is required given the possibility of malignant transformation according to age and morphologic features. This evidence concerns the gene PTCH1 and skin basal cell carcinoma.