Fetal axillary cystic hygroma: a novel association with triple X syndrome.

Background: Triple X syndrome is a relatively common sex chromosomal aneuploidy with an estimated incidence of one in every 1000 female births. There is considerable diversity in phenotypes among patients with triple X syndrome. Triple X syndrome has been shown to have associated abnormalities, with genitourinary malformations being the most consistent. Cystic hygroma (CH) is a lymphatic malformation that occurs because of the lack of development of communication between the lymphatic and the venous systems. CH has an incidence of 1 in every 6000-10,000 live births. CH is associated with a variety of conditions, including chromosomal aneuploidies and fetal malformations.

Case: We report a case of prenatally detected triple X syndrome with axillary CH as an isolated finding. The patient was referred because of a fetal cystic mass at the right axillary region. Amniocentesis revealed 47,XXX karyotype, and no additional abnormalities were detected prenatally or after abortion.

Conclusion: This is a novel description of axillary CH associated with triple X syndrome.