The histological findings in transposition of the great artery with severe persistent pulmonary hypertension of the newborn.

The combination of persistent pulmonary hypertension of the newborn (PPHN) and transposition of the great arteries (TGA) has serious impacts on treatment and prognosis, often with adverse outcomes. We report the case of a male full-term newborn with TGA with intact ventricular septum and severe PPHN who died 2 h after birth; further, we examined his vascular histology. On autopsy, lung histology showed mild fibrous hypertrophy in the intima and moderate medial hypertrophy of the minimal pulmonary artery. Hypoplasia of the pulmonary artery was not detected. Pulmonary congestion was detected and pneumatization was poor. Debris was present in the alveoli. Hemosiderin deposition was detected, suggesting prenatal hemostasis or hemorrhage. Severe PPHN may have occurred because of pulmonary arterial spasm accompanying pulmonary congestion which had been in the fetal stage. A wide range of lesions can be present in the pulmonary vascular bed in TGA. The pathologies of pulmonary vascular tissues with TGA and PPHN are not uniform. <Learning objective: Neonates with transposition of the great arteries with intact ventricular septum (TGA/IVS) may have severe pulmonary hypertension. The progression of pulmonary vascular disease in TGA/IVS is unpredictable; therefore, the delivery of a fetus diagnosed with TGA/IVS should be performed at an institution in which catheterization and balloon atrial septostomy can be performed.>.