4.1 Etiology
ACC was first reported by Gordon in 1767 and summarized by Campbell in 1826[6]. It is occurring mainly on the top of the head but can occur anywhere on the body[5]. The cause of ACC is unknown. Genetics and exogenous factors may play a role in the development of the lesion. Suspected exogenous causes include intrauterine trauma, localized amniotic adhesions, and exposure to teratogenic substances such as antithyroid drugs, valproic acid, marijuana, heroin, alcohol, and cocaine during pregnancy[7]. The occurrence of ACC has also been associated with skin tears due to excessive tension in the fetal skin and subcutaneous tissues, with the top of the head being the most tensioned area[8]. The only thing that has been established is that the occurrence of congenital dermal dysplasia is genetically related. Most of these lesions are disseminated, but approximately 25% are autosomal dominant or recessive. Other genetic abnormalities associated with congenital dermal dysplasia include autosomal aberrations, deletions, trisomies and mutations.No identified genetic target for ACC had been identified, but a recent study suggests a possible role for the BMS1 gene. In a 2013 study that examined five generations of autosomal dominant ACC, mutations in the BMS1 gene were found to play an essential role in skin morphogenesis[9]. ACC can also be associated with various genetic syndromes such as ADAMS-Oliver syndrome, Bart syndrome, and Setleis syndrome. There was no family history of genetic predisposition or exposure to drugs and teratogenic substances during pregnancy in both cases. The same point is that both are macrodome, and it is considered that the fetus grew rapidly during pregnancy, causing congenital skin dysplasia due to hypertonicity of the skin tissue on the top of the head.