Fig. 3

Radiographic and histopathological findings of the fourth child. a Chest X-ray reveals a diffuse decrease in translucency in the bilateral lung fields. b Misaligned pulmonary veins (v) run alongside the small pulmonary arteries (a) within a common adventitial sheath and a bronchiole (b). c Elastica van Gieson staining highlights the malposition of a pulmonary vein and artery. d Thickening of the alveolar wall and dilation of vessels. Immunohistochemical staining for CD31 shows a decreased number of pulmonary capillaries located away from the alveolar epithelium (inset). e Most of the lymphatic vessels in the interlobular septa are dilated without endothelial proliferation, and glomeruloid endothelial proliferation was limited to a small area (f)