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
Imaging: Stocker classification based on size of dominant cyst
— Type 0 (rare): Acinar dysplasia leads to small and firm lungs incompatible with life
— Type 1 (60-65%): Cysts are 2-10 centimeters in size
— Type 2 (20%): Cysts are 0.5-2.0 centimeters 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 with midline shift
Imaging CXR: Retention of fluid at birth and air trapping later
DDX: Pneumatocoele – pneumatocoele should decrease in size over time, congenital pulmonary airway malformation increases in size over time
Complications: Type 4 may be a precursor to pleuropulmonary blastoma
Treatment: Surgical due to respiratory symptoms
Clinical:

Radiology Cases of Congenital Pulmonary Airway Malformation

Radiology Cases of Congenital Pulmonary Airway Malformation Type I

CXR of congenital pulmonary airway malformation Type I — CXR AP and lateral shows a large septated cystic lesion filling nearly the entire left hemithorax and causing mass effect with depression of the left hemidiaphragm and mediastinal shift to the right.

CT of congenital pulmonary airway malformation Type I — CXR at birth (above left) shows an ill-defined large mass in the lower left chest obscuring the heart border and causing mediastinal shift to the right. Axial CT without contrast of the chest at birth (above right) shows the left chest mass to contain multiple cysts that are filled with air and fluid. CXR at 10 months (below left) shows the large lower left chest mass to now be hyperlucent. Axial CT without contrast of the chest at 10 months (below right) shows the left chest mass to contain multiple large air-filled cysts.

CXR and CT of congenital pulmonary airway malformation type I — CXR AP and lateral (above) show a round heterogenous mass in the right upper lobe. Axial CT without contrast of the chest (below) shows a dominant central cyst in the lung surrounded by many smaller cysts.

CXR and CT of congenital pulmonary airway malformation type I — CXR AP and lateral (above) shows a large cystic lesion in the right upper lobe. Axial CT with contrast of the chest (below) shows the lesion consisted of a single cyst.

Radiology Cases of Congenital Pulmonary Airway Malformation Type II

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.

CT of congenital pulmonary airway malformation — Axial (above) and coronal (below) CT with contrast of the chest show a round mass in the right superior hilum that consists primarily of fluid density with a small air bubble in it superiorly.

Radiology Cases of Congenital Pulmonary Airway Malformation Type III

Surgical Cases of Congenital Pulmonary Airway Malformation

Surgical image of congenital pulmonary airway malformation — Surgical image shows multiple cystic lesions in the right upper lobe. The right middle and right lower lobes were normal.

Gross Pathology Cases of Congenital Pulmonary Airway Malformation

Pathological image of congenital pulmonary airway malformation / CPAM / CCAM / congenital cystic adenomatoid malformation — Pathological image shows multiple cystic lesions in the right upper lobe.

Pathology image of congenital pulmonary airway malformation — Gross pathological image of the sectioned left lung shows multiple large cystic lesions throughout the entire lung.

Histopathology Cases of Congenital Pulmonary Airway Malformation

Histopathology image of congenital pulmonary airway malformation — Histopathological image of H&E stained section shows dilated “alveolar” spaces lined by a combination of both respiratory and mucus-secreting epithelium.