Le chylothorax idiopathique est rare, sa prévalence étant située entre 1/8600 et 1/15 000 naissances. Plus rarement révélé après la période néonatale, son diagnostic positif est facile, par analyse du liquide pleural. Sa prise en charge repose sur le drainage du liquide pleural, la suppression des graisses alimentaires, la renutrition ainsi que le traitement de la cause quand celle-ci est connue. Par ailleurs, certains médicaments ont montré leur efficacité dans la diminution de la production du chyle. Le recours à la chirurgie est préconisé devant l’échec du traitement médical ou l’abondance du liquide chyleux. Nous rapportons l’observation d’un nourrisson de 9 mois hospitalisé pour un chylothorax idiopathique.

Chylothorax is a rare disease (1–2 % of pleural effusions), with a prevalence between 1/8600 and 1/15,000 births. It is characterized by the presence of chyle in the pleural cavity. Three categories of chylothorax are known: congenital chylothorax, which can be either idiopathic or the result of a malformation, and traumatic chylothorax (mostly postoperative). We report the observation of a 9-month-old infant with idiopathic chylothorax revealed by respiratory symptoms, with pleural effusion and collapse of the ipsilateral lung on chest X-ray and ultrasound examination. Cytology and chemical analysis of the pleural fluid showed an exudative liquid with a chylous aspect, a high concentration of albumin (52g/dL), triglycerides (11.42g/L), and a high number of cells (6600 cells/mL), with lymphocyte predominance (96 %). The culture was sterile. Chylothorax is usually revealed by dyspnea, but also by nausea, vomiting, anorexia and/or malnutrition. The diagnosis is suspected when milky white fluid is obtained from thoracocentesis and is confirmed by the presence of a triglyceride level greater than 1.2mmol/L and more than 1000 cells/mL, with lymphocyte predominance. The treatment of chylothorax can be either conservative or surgical. Conservative treatment (medical) has four goals: ensure pleural emptiness, decrease production of chyle, restore and/or maintain proper nutritional status, and treatment of the cause when identified. Surgical intervention is indicated when conservative management fails and aims to stop a radical and permanent leakage of chyle.