Rare congenital pulmonary malformation with diagnostic challenging: congenital pulmonary lymphangiectasia, report of four autopsy cases and review of literature.

Congenital pulmonary lymphangiectasia (CPL) is a rare congenital disorder that typically presents with intractable respiratory failure in the first few days of life. There is an association non-immun hydrops and CPL. In this study we reviewed four CPL cases between January 2006 and January 2014 among 684 fetal-pediatric autopsies. All cases were in the second trimester. In light microscopy there were marked dilatated channels in the subpleural -peribronchial-subseptal region of the lungs. The channels were lined with flattened cells which were expressing CD 31 and D2-40, negative for CD34. Although pulmonary interstitial emphysema (PIE) was considered an important differential diagnosis, a giant cell reaction surrounding the interstitial cystic lesions, a histological hallmark of PIE. CPL is characterized by dilatation of the pulmonary lymphatic vessels and occurs as a congenital anomaly. Noonan classified it into three groups. Primary developmental defect of pulmonary lymphatics is group 3. Group 3 is called also as CPL; normal regression of the connective tissue elements fails to occur after the 16th week of fetal life, associated with an aggressive clinical course, poor prognosis. In fetal autopsy examination CPL should be recognized if there is a fetus with pleural effusion, non-immune hydrops. There is no clinical evidence for CPL.