[Echographic diagnosis of cystic hygroma. Apropos of a case].

A case of nuchal cystic hygroma associated with non immune hydrops fetalis and renal malformation in one of two twins observed at 18th week of gestation is reported. Occurrence of acute polyhydramnios and severity of the anomalies showed by serial ultrasound scans has led to termination of pregnancy induced by prostaglandin E. This rare malformation is related to an abnormality of the lymphatic system and is usually associated with monosomy 45 XO or Turner syndrome.