CASE 13566 Published on 11.04.2016

The postnatal differential diagnosis of four patients with antenatal diagnosis of congenital pulmonary airways malformation (CPAM)


Paediatric radiology

Case Type

Clinical Cases


Catalin V Ivan, Mandip Heir, Fiona Dickinson

Leicester Royal Infirmary, UK
Infirmary Square

1 years, female

Area of Interest Thorax, Foetal imaging ; Imaging Technique CT, MR
Clinical History
We report on four cases of paediatric patients with antenatal diagnosis of congenital pulmonary airways malformation (CPAM), performed either by antenatal ultrasound or fetal MRI. All patients subsequently underwent further radiologic investigations post-natally as part of the pre-operative planning.
Only one of the four cases was confirmed to have CPAM.
Imaging Findings
Patient A had chest radiographs and an abdominal ultrasound which revealed multiple air-filled bowel loops occupying the left hemithorax, confirming the diagnosis of left congenital hernia.

Patient B underwent enhanced chest CT scan, which showed a 30mm x 14mm heterogeneous enhancing lesion in the posterior basal segment of the left lower lobe. The lesion was supplied by a systemic artery arising from the distal descending thoracic aorta and the venous drainage was to a branch of the left inferior pulmonary vein. These findings were consistent with intra-lobar sequestration.

Patient C had a large cystic mass replacing the right lower lobe on the CT scan consistent with CPAM.

For Patient D the CT scan showed a cystic mass adjacent to the left hilum with absence of the left upper lobe apical-posterior segmental bronchus and hyper-expansion of this segment of lung. The findings were consistent with bronchial atresia.
Congenital pulmonary airways malformation (CPAM) previously known as congenital cystic adenoid malformation (CCAM) is a rare abnormality of the normal broncho-alveolar tract morphogenesis. The use of prenatal ultrasonography has led to an increase in prenatal diagnosis with an estimated incidence of 1: 8300 to 1: 35 000 live births [1, 2]. The National Institute for Health and Care Excellence has introduced routine antenatal ultrasound screening for abnormalities between 18 and 20 weeks of gestation in 2008 in the UK [6].

More recently, fast sequence MRI such as Half-Fourier Single Shot Turbo Spin-Echo or Gradient Echo acquisition, has been shown to be a useful additional investigation to ultrasound by providing a more detailed anatomical description and by aiding the differential diagnosis, especially when there is doubt between CPAM and a congenital diaphragmatic hernia. Moreover, the images of the fetus on MRI are easier to be understood by the clinicians and parents not familiar with foetal imaging [3, 4]. The main disadvantages of the MRI are that it remains more expensive, time consuming and less readily available than ultrasound.

However, Zeidan S. et al have shown that antenatal MRI is less accurate than the postnatal CT which is the most reliable examination especially for the pre-operative planning of these patients [5]. There are five sub-types of CPAM with varying imaging characteristics making accurate antenatal diagnosis even more difficult.

In the case of patient A, a chest radiograph and a post-natal ultrasound provided enough information to alter the diagnosis and help plan for congenital hernia repair surgery. There were no post-operative complications and the patient was discharged in the community.

In the remaining three cases, the CT scan was essential in reaching a final diagnosis.

For patient B who underwent local excision surgery with very good outcome, the CT scan had helped not only in clearing the diagnosis but for pre-operative planning as well, providing the surgeons key information regarding the location of the lesion and the vascular supply.

Patient C underwent right lower lobectomy with no significant complications and was discharged with surgical follow-up.

Patient D remained asymptomatic and no surgical intervention was required. The CT scan helped in reaching the correct diagnosis and preventing a potential unnecessary surgical intervention.
Differential Diagnosis List
Congenital hernia. Intra-lobar sequestration. CPAM. Bronchial atresia.
Congenital hernia
Intra-lobar sequestration
Bronchial atresia
Final Diagnosis
Congenital hernia. Intra-lobar sequestration. CPAM. Bronchial atresia.
Case information
DOI: 10.1594/EURORAD/CASE.13566
ISSN: 1563-4086