ABSTRACT
INTRODUCTION AND IMPORTANCE: Chylous ascites is a rare condition in children wherein milky fluid accumulates in the abdomen. It is caused by various factors and presents with abdominal distension. Diagnosis involves imaging and fluid analysis obtained through paracentesis. Treatment options range from conservative measures to surgery. The association with congenital hypothyroidism is not well-established. CASE PRESENTATION: A 3-week-old male infant presented with abdominal distention. Diagnosis revealed congenital chylous ascites and congenital hypothyroidism. Initially, he was treated conservatively with medium-chain triglycerides and total parenteral nutrition, paracentesis, and thyroid hormone supplementation. The patient's condition worsened, necessitating octreotide therapy, blood transfusion, and antibiotics. The conservative treatment failed, and the patient underwent surgery; however, the exact source of fluid leakage could not be identified. Follow-up ultrasound examinations showed no ascitic fluid in the subsequent months. CLINICAL DISCUSSION: Congenital chylous ascites can be caused by congenital malformations or idiopathic factors. Symptoms include abdominal distension and respiratory difficulties. Diagnosis involves imaging and fluid analysis through paracentesis. To our knowledge, this represents the third case of congenital chylous ascites in the associated with congenital hypothyroidism described in the literature and the first one to be treated with surgery. CONCLUSION: Treatment options range from conservative measures such as diet management and paracentesis to somatostatin therapy. Surgery is considered in refractory cases. An association between congenital hypothyroidism and congenital chylous ascites has been reported in few cases.