Sites of basal cell carcinomas and head and neck congenital clefts: Topographic correlation

Background: The embryologic fusion planes might be related with the sites of onset of basal cell carcinoma (BCC), thus supporting an embryologic role for its pathogenesis. Methods: A study involving 495 patients with 627 BCCs of the head and neck was carried out over a period of 5 years by correlating the distribution of all BCCs with the sites of congenital clefts of the head and neck using (1) the original anatomic diagram of the Tessier classification of craniofacial clefts, (2) the anatomic diagram by Moore et al featuring the paths of the "hairline indicators" of craniofacial clefts that represent the cranial extensions of the Tessier classification, and (3) an anatomical diagram featuring the sites of congenital clefts of the neck. Results: The proportion of BCCs localized within a cleft site was significantly higher than those in the noncleft sites. The age of patients with BCCs localized within the Tessier cleft number 3 was the lowest among all cleft regions. Conclusions: A topographic correspondence between the sites of BCCs and the sites of congenital clefts was demonstrated in the head and neck. This evidence would support the hypothesis of an embryologic role for the pathogenesis of BCC. The existence of clusters of embryological stem cells in the sites of fusion and/or merging of embryonic processes might therefore be proposed. There may be special biology/physiology along these cleft lines that predispose BCC formation.