Aim: To determine whether similarities exist in both the imaging and histopathological features of congenital cystic lung lesions and whether a more appropriate classification would be to adopt the theory of "malinosculation".
Material and methods: From the histopathology and computed tomography (CT) database, 24 patients (16 male, median age 3 years) with congenital cystic lung lesions were identified. CT studies were reviewed for site and characteristics of the lesions, parenchymal features, bronchial anatomy, and the presence of a feeding systemic vessel. Individual histopathological parameters were also correlated with CT data.
Results: There were five type 1 congenital cystic adenomatoid malformations (CCAMs), six type 2 CCAMs, one type 4 CCAM, one bronchial atresia, four pleuropulmonary blastomas (PPBs), and seven sequestrations. CCAMs (types 1, 2 and 4), sequestrations and PPBs appeared as cystic lesions, with cyst size less than 2 cm in type 2 CCAMs. Sequestrations were distinguished radiologically from CCAMs by systemic vessels. Reduced pulmonary attenuation was seen in bronchial atresia, type 2 CCAMs and in sequestrations. Histopathology showed an overlap in entities with sequestrations demonstrating CCAM type 2 histology and segmental atresia noted in both type 2 CCAMs and sequestrations. PPBs showed histological and imaging overlap with type 4 CCAMs and were distinguished on histology by the presence of blastematous proliferation.
Conclusions: This study demonstrates overlap in the CT appearances of congenital cystic lesions. The similarity in CT and histopathology findings across the spectrum of developmental lesions supports the hypothesis of a common aetiology.