Lethal hypoplasia and developmental anomalies of the lungs in a newborn with intrauterine adrenal hemorrhage and cerebral infarcts: a proposed pulmonary disruption sequence.

We report a case of a 31-week-gestation male newborn who died soon after birth from intractable respiratory failure and persistent pulmonary hypertension. The pregnancy had been complicated by intermittent bleeding between 13 and 20 weeks' gestation, attributed to peripheral placental separation, as well as bilateral fetal adrenal hemorrhage, first detected at 17 weeks' gestation. Postmortem examination revealed small, calcified adrenal glands as well as several remote cerebral and cerebellar infarcts. The lungs were hypoplastic (lung weight/body weight ratio: 1.64%; 10th percentile for 28-36 weeks' gestation: 2.27%) and distorted by exaggerated lobulation. Microscopically, the lungs exhibited several developmental anomalies, including focal acinar dysgenesis suggestive of arrested development in the pseudoglandular stage of development (8-16 weeks' gestation) (mainly in the upper lobes), and features of bronchial obstruction, including focal lobular hyperplasia and microcystic maldevelopment (mainly in the lower lobes). The adrenal and cerebral findings were consistent with a severe early-gestation hypoxic-ischemic insult, likely related to peripheral placental separation and chronic abruption. The co-occurrence and timing of these well-recognized hypoxic lesions provide further evidence that certain developmental lung anomalies, such as focal acinar dysplasia, focal lobular hyperplasia, and microcystic maldevelopment, may, at least in some cases, have a hypoxic/ischemic etiology.