Abstract
Chylothorax is defined as accumulation of lymphatic fluid in the pleural space. Chylothorax in the neonatal period can be classified into three distinct categories: congenital chylothorax (CC), syndromic or malformative chylothorax (MC) and postoperative chylothorax (CO). Although rare, chylothorax is the most common cause of pleural effusions in the neonatal period. Making a positive diagnosis is easy by examination of the pleural fluid, but its mechanism and especially the integrity of thoracic duct and its collateral branches is sometimes difficult to determine. Lymphoscintigraphy is the test of choice in etipathogenic diagnosis. This diagnostic tool can be coupled, if possible, to SPECT-CT (single photon emission tomography / computed tomography) providing more specific anatomical informations. Tratment of chylothorax is based on the drainage of the pleural fluid, the suppression of dietary fats and on parenteral nutrition. Surgery is recommended in the case of medical treatment failure. We report the case of a newborn with unilateral chylothorax who did not respond to medical treatment. Lymphoscintigraphy allowed to diagnose etiopathogenic mechanism underlying chylothorax and therefore to direct surgical treatment.