Pulmonary embolism in a child with combined methylmalonic acidemia and homocystinuria

INTRODUCTION Pulmonary embolism is much less common in children than in adults.We encountered a 5-year-old girl with pulmonary embolism.She was finally diagnosed with combined methylmalonic acidemia and homocystinuria,which is a rare disease that could cause pulmonary embolism.Pulmonary embolism in our patient may be considered a case of in situ thrombosis of pulmonary arteries rather than classical thromboembolic pulmonary embolism.The clinical experience in this patient suggests that the possibility of metabolic disease should be considered when encountering pediatric pulmonary embolism.