[Alveolar capillary dysplasia with misalignment of pulmonary veins: a fatal cause of refractory neonatal cyanosis].

Alveolar capillary dysplasia with misalignment of pulmonary veins (ACD/MPV) is a rare neonatal pathology that combines refractory hypoxemia with severe pulmonary arterial hypertension, and leads to death every time. Histologic examination of lung tissue confirms the diagnosis and is characterized by a decreased number of pulmonary capillaries, immature lobular development, and abnormal proximity between pulmonary arteries and veins. This abnormal proximity is responsible for an arteriovenous shunt. We report five cases confirmed by postmortem histology, which occurred over 14 years in Lower Normandy (France). The cumulative incidence is therefore of 1.8 for 100,000 births. In these five cases, the first symptoms appeared during the first hour of life and death occurred before 24h in four of five cases. The patient with the longest survival had mild histological lesions and delayed emergence of the first symptoms. Genitourinary and gastrointestinal anomalies were associated with ACD/MPV in two cases, and bilateral pulmonary hypoplasia in three cases. Optimized invasive ventilation, pulmonary vasodilators, vasoactive drugs, and pulmonary surfactant did not improve survival. Extracorporeal membrane oxygenation (ECMO) was not used. We present a review of the literature on ACD/MPV, a clinical and histological entity little known to both clinicians and pathologists, whereas a premortem diagnosis is possible and genetic counseling in affected families can be suggested.