Congenital Pulmonary Airway Malformation

  • Etiology: abnormally formed hamartomatous lung tissue with bronchial overgrowth that lacks supporting cartilage and arrested alveolar development, has communication with bronchial tree, maximum growth is at 20-26 weeks gestational age with 15% regressing between 32-34 weeks gestational age, can be in any lobe
  • CXR: retention of fluid at birth and air trapping later
  • Imaging: Stocker classification – Type 0 (rare) – acinar dysplasia -> small and firm lungs incompatible with life, Type 1 (60-65%) – cysts are 2-10 cm in size, Type 2 (20%) – cysts are 0.5-2.0 cm in size and can be associated with sequestration = hybrid lesion, Type 3 (5-10%) – microscopic cysts that appear solid by imaging, Type 4 (10%) – large cysts = Type I pleuropulmonary blastoma with midline shift
  • DDX: pneumatocoele – pneumatocoele should decrease in size over time, CPAM increases in size over time
  • Treatment: not a precursor to pleuropulmonary blastoma, surgical due to respiratory symptoms

Cases of Congenital Pulmonary Airway Malformation

CXR of congenital pulmonary airway malformation
CXR shows the left hemithorax filled with multiple cysts of various sizes causing mediastinal shift to the right. There is herniation of some normal appearing left apical lung across the midline. The stomach is in the abdomen.
Pathological image of congenital pulmonary airway malformation / CPAM / CCAM / congenital cystic adenomatoid malformation
Pathological image shows multiple cystic lesions in the right upper lobe.