Prenatal Ultrasonograpy of Cystic Hygroma in Unusual Site

Among 2,055 cases of abnormal findings detected by prenatal ultrasonography at Yonsei University College of Medicine from January 1996 to June 2002, the incidence and the site of cystic hygroma were evaluated. The clinical courses and postnatal prognosis were studied in four cases with cystic hygroma developed in unusual sites. Among 2,055 cases of abnormal ultrasonographic findings, 76 cases (3.70%) were diagnosed as cystic hygroma. Among 76 cases of cystic hygroma, 4 cases (5.3%) were detected in unusual sites; 1 case in mediastinum, 1 right axillary area, and 2 in anterolateral portion of neck. In cystic hygroma, prenatal accurate ultrasonographic findings including size and site of mass are important. Cystic hygroma developed in unusual sites are associated with perinatal complications including airway obstruction and compression of the surrounding organs. In giant cystic hygroma, cesarean section should be considered to avoid trauma and birth injury. After delivery, close observation and proper management are required.