Old terminology is Congenital Cystic Adenomatoid Malformation ( CCAM)
CPAM is developmental hamartomatous abnormality of the lung with adenomatoid proliferation of cysts resembling bronchioles.
CPAM communicates with bronchial tree at birth and fill with air early in life.
CPAM has no lobar predilection unlike congenital lobar emphysema.
Most lesions are confined to single lobe.
Incidence 1 per 100,000 births
TYPES: 3 depending on the size of the cysts.
Type I: 50% 1 or more large (2-10cm ) cysts.
Type 2: 40% Numerous small cysts of uniform size from 0,5 -2 cm. Associated with other congenital anomalies ( renal, skeletal, intestine and cardiac)
Type 3: 10% Appears solid on gross imaging and inspection but have microcysts.
TAKE HOME MESSAGE: Small risk for malignant degeneration –Rhabdomyosarcoma and bronchoalvelolar cell carcinoma.