Mongolian spots associated with cleft lip.

Of the present series comprising 66 newborns with cleft lip, 13 (20%) had pigmented macules in the labial skin on the lateral side of the cleft. Histological examination using serial sections were performed on 47 cases and showed evidence of dermal melanocytosis in 40 cases (85%) consisting of 33 (70%) without clinically detectable macules and 7 (15%) with obvious pigmented macules. The fusiform cells in the dermis were positive for dopa reaction and anti-melanocyte antibody. The high incidence of dermal melanocytosis is comparable to that of common Mongolian spots in Asian babies.