[Idiopathic chylothorax in an infant: management and progression].

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 (52 g/dL), triglycerides (11.42 g/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 1.2 mmol/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.