During the past few years the condition described as congenital cystic disease of the lung has attracted considerable attention. No longer accidentally observed at necropsy, the lesion is recognized during life, and in a number of cases it can be successfully treated. Synonymous terms, such a fetal bronchiectasis, congenital bronchiectasis, atelectatic bronchiectasis and congenital pulmonary lymphangiectasis, have been replaced by the more proper designation, namely, congenital cystic disease of the lung. Responsible for initiating the recent interest in this condition was Koontz,1 who reviewed the literature in 1925 and collected reports of 108 proved cases. In a recent communication (1936) I2 reported from the world's literature an additional 124 cases and 4 original cases, making a total of 236 cases of congenital cystic disease of the lung on record. Since the writing of my last paper, or in the past year and a half, 140 additional reports of