[Current aspects of cystic lymphangioma in the neck].

Cystic hygroma of the neck (CHN) is the result of a defect in the embryonary development of the lymphatic system. In many cases foetal ultrasound allows an early diagnosis before birth, the prognosis being very different according to the gestational age at the time of detection. When discovered before 30 weeks of gestation it is almost always associated with chromosomal abnormality and/or polymalformation leading to spontaneous or therapeutic abortion. On the contrary when appearing after the 30th week of gestation, CHN is usually an isolated malformation as when discovered during infancy or childhood. Approximately 2/3 of these "late" CHN are present at birth; 90% are discovered before 2 years of age. A spontaneous regression occurs in about 15% of the cases. In 70% of cases the CHN is simple without extension to the oropharynx or mediastinum and its complete surgical resection is usually easy. Extension to the oropharynx is present in about 20% of the cases; there is a risk of neonatal respiratory distress and the treatment is difficult. Extension to the mediastinum is found in about 10% of the cases; respiratory distress is rare and a large surgical resection is necessary. Surgery is the primary treatment of CHN after a careful evaluation of the extension of the tumor by ultrasound, scanography or nuclear magnetic resonance, and oropharyngeal endoscopy. It allows a "macroscopically complete" resection in about 80% of the cases, but a recurrence is observed in approximately one every five cases. Following partial resection or important recurrence, treatment includes according to the cases; new attempt of surgical resection, sclerosing therapy, and laser therapy for the oropharyngeal forms.