Chest / Cardiac for Monday, April 7th, 2025

Contributed by Saint Louis Children's Hospital - Washington University
Noah Seymore.

History

A 5-day old previously healthy term infant presented to the pediatric ER with cyanosis. Patient was intubated and chest radiographs were obtained. 

Patient was admitted with findings of thrombocytopenia, hypotension, and tachycardia. Abdominal and intracranial ultrasounds were negative. Symptoms persisted after 24 hours despite empiric broad spectrum antibiotics. 

An echocardiogram showed evidence of right heart strain and a CT Angiogram of the chest was performed. 

Images (Click any image to enlarge)

Question

What is the diagnosis?

Your answer

Please log in to see your results.

Correct answer

Neonatal Pulmonary Embolism

Discussion

Chest radiograph demonstrates an intubated infant with asymmetrically lucent right lung and left lower lobe. 

CTA of the chest demonstrates a large right pulmonary artery occlusive thrombus. Occlusive thrombus was also present in the left lower lobe pulmonary artery branch (not shown). This results in oligemia and resulting lucent appearance of the right lung and left lower lobe, which is highlighted on iodine mapping images. 

Pulmonary emboli in children have peak incidence in adolescents and infants less than one year of age. Despite this, cases in infants are extremely rare, with the most common cause by far being central venous catheters followed by other acquired conditions such as surgery, trauma, or infection. Other less common risk factors include maternal conditions and inherited/congenital abnormalities such as coagulopathies.  Very often the cause is unknown and remains idiopathic, as in this case. It may be underdiagnosed due to rarity and low level of suspicion, and as such the diagnosis may only be clearly established at autopsy, as up to 10% of patients die within the first hour of presenting with symptoms. Depending on severity patients may be anticoagulated or may require catheter-directed thrombectomy/thrombolysis (as in this case) or even surgical thrombectomy. 

Differential diagnosis

Pediatric unilateral lucent lung has both common and classic diagnoses, ranging from causes such as bronchial intubation or atelectasis, foreign body aspiration, pneumothorax, or congenital causes such as congenital pulmonary airway malformations, congenital lobar over-inflation, bronchial atresia, Poland syndrome, or spectrum of pulmonary vascular abnormalities (agenesis, proximal interruption of the pulmonary artery, or Scimitar syndrome). Pulmonary emboli is rare but should be considered in the differential, particularly if risk factors are present.

References

  • Curry DE, Erker C, Price V, Midgen C, Mohsin H, Sett S, et al. Massive saddle pulmonary embolism in a preterm neonate with successful emergent open embolectomy. CJC Pediatric and Congenital Heart Disease. 2022 Feb;1(1):40–3.
  • Paes BA, Nagel K, Sunak I, Rashish G, Chan AK. Neonatal and infant pulmonary thromboembolism. Blood Coagulation & Fibrinolysis. 2012 Oct;23(7):653–62.
  • Wasilewska E, Lee EY, Eisenberg RL. Unilateral hyperlucent lung in children. American Journal of Roentgenology. 2012 May;198(5).