A rare case report of Edwards syndrome with immature teratoma in submandibular region and literature review.

Trisomy 18 (Edward syndrome) was first described by Edwards et al. in 1960. The condition is the second most common autosomal trisomy syndrome in males. The prevalence in infants is estimated as 1/6000-1/8000. Those affected have a high mortality rate - only 4% may survive their first year.