Neonatal chylothorax results from the accumulation of chyle in the pleural space and may be either congenital or an acquired
condition. Congenital chylothorax is most likely due to abnormal development or obstruction of the lymphatic system and often
associated with hydropsfetalis. It can be idiopathic or may be associated with various chromosomal and other genetic abnormalities.
It is important to identify infants with chylothorax, as there are specific issues that need to be addressed in the management of these
patients. In the neonate, chylous effusion is a common cause of pleural effusions and characterized as an exudate because of the high
protein and lipid content once the infant is fed. The fluid will be clear/yellow to slightly cloudy in the unfed state and will quickly
become milky following feeding, as chylomicrons appear in the fluid. Lymphocytes predominate in the differential cell count of
chyle. The volume of fluid output can be high, and management can be challenging.
We present a case of newborn with 21 trisomy who developed moderate RDS, chest X-ray and US reveal pleural effusion on
right side, rapid intervention was made before deterioration, requiring intensive life-saving measures. We review the common
manifestations of congenital chylotoraxes and emphasize the importance of early diagnosis and intervention in preventing
devastating outcomes from this condition.