Prenatal sonographic diagnosis of isolated congenital cystic hygroma, unassociated with lymphedema or other morphologic abnormality.

We report the prenatal sonographic diagnosis of five cases of isolated cystic hygroma (lymphangioma), unassociated with lymphedema or other morphological abnormalities. This type of cystic hygroma appears different from the ones occurring at the back of the neck, which have other lymphatic anomalies and a poor prognosis. Four of the five fetuses did well after surgery. We describe the sonographic appearance of this type of cystic hygroma, which is different from the nuchal type as it is primarily complex.