Congenital cystic adenomatoid malformation of the lung: a case report with embryological review

Congenital cystic adenomatoid malformation (CCAM) is a rare developmental dysplastic lesion that affects the fetal bronchial tree. Etiopathogenesis is still poorly understood. Most accepted view is that of abnormal branching of bronchioles during the period of morphogenesis. We observed a rare congenital anomaly of the lungs during fetal autopsy. Routine antenatal ultrasonography revealed multiple echolucent cysts in the right lung of the fetus. Thorough external and internal examination was followed by sectioning of each organ for histopathological examination. Histopathology of the right lung showed distortion of the parenchyma with dilated bronchioles. Multiple cysts lined by columnar epithelium along with loose intervening connective tissue were observed along with many congested and dilated blood vessels. Knowledge of congenital anomalies of the respiratory system would help clinicians to plan the management at a very early stage. Accurate fetal autopsy along with clinical data is important in evaluating fetal deaths and can help in reducing unexplained stillbirths.