congenital cystic adenomatoid malformation
congenital cystic adenomatoid malformation
A rare developmental defect of the lungs seen primarily in infants, which displays both immaturity and malformation of the small airways and parenchyma distal to it. Pulmonary sequestration can be difficult to distinguish from congenital cystic adenomatoid malformation (CCAM), but the presence of a feeding artery from the systemic circulation is helpful.Types
Type 0: Very rare, incompatible with life; presents as a solid mass containing bronchial-like structures and abundant cartilage.
Type 1: Most common type; contains large, multilocular cysts with broad fibrous septa, mucinous cells and focal cartilage.
Type 2: Contains small, cystically dilated bronchiolar structures (usually <2.0 cm) lined by respiratory epithelium; wall may contain striated muscle.
Type 3: Presents as a solid lesion with minute cysts (usually <0.2 cm) lined by cuboidal epithelium, surrounded by immature, fetal-type parenchyma.
Type 4: Has large cysts that are peripheral and are lined by type-1 pneumocytes and low columnar epithelium and have hypercellular stroma.