[Congenital lymphangiectasis of the lungs (so-called primary and secondary forms) and lymph vessel dilation in hyaline membrane syndrome].

In five cases of congenital pulmonary lymphangiectasis, light microscopic features of the lungs and measurements of their lymph vessel lumina are presented. All lung sections show the same histologic characteristics: a network of partly tubular, partly cystically enlarged lymph vessels within large areas of connective tissue. The lung sections in four cases with pulmonary vein outflow obstruction, the so-called secondary form according to NOONAN et al. [28], do not differ from those in primary lymphangiectasis without obstruction in the pulmonary vein outflow area. The author's own observations are discussed together with 57 cases from the literature. Among the 26 cases of secondary lymphangiectasis are 15 children with aberrant pulmonary veins, and 11 children with hypoplasia of the left side of the heart. Clinically, both forms present with neonatal asphyxia and massive respiratory distress, usually with a fatal outcome within the first few days of life. Hyaline membrane disease may be accompanied by pulmonary lymphangiectasis to a degree that renders its distinction from congenital lymphangiectasis difficult. The lungs in 5 cases with hyaline membrane disease are compared to those in 5 cases of congenital lymphangiectasis. In the former, distended lymphatics are primarily interlobular in location, while in congenital lymphangiectasis they are also found in the subpleural and periarterial tissues. In addition, they are widened to a lesser degree than in the congenital form. In the latter the lymphatic vessel walls are markedly thickened, and the pulmonary lesions, particularly the signs of immaturity, typical for hyaline membrane disease, are lacking.