A case of occipital encephalocele combined with right lung aplasia in a twin pregnancy.

A case of occipital encephalocele combined with right-sided pulmonary agenesis in one sibling of a twin gestation is presented. Both, encephalocele and lung aplasia, are rare conditions, the former occurring with a frequency of 1:3000-1:30,000, the latter in 1:10,000-1:30,000. Although both conditions may show concomitant malformations, to our knowledge this is the first case of a combination of these two malformations to be reported.