Misplaced pulmonary arteries in an adult patient with pulmonary hypertension

Misalignment of pulmonary vessels, with or without alveolar capillary dysplasia, is a rare cause of persistent pulmonary hypertension in the newborn. The prognosis is poor, with virtually all patients succumbing to unremitting hypoxaemic respiratory failure and death during the newborn period. We report the CT and histological findings of misplaced pulmonary arteries in a previously healthy young adult patient who presented with pulmonary arterial hypertension. Contiguous high-resolution spiral CT angiography showed small pulmonary arteries coursing within the interlobular septa and enlarged central pulmonary arteries. Surgical lung biopsy demonstrated anomalous muscularised pulmonary arteries in the interlobular septa. This is, to our knowledge, the first report of misplaced pulmonary arteries presenting in an adult patient and may represent a forme fruste of the neonatal vascular anomaly. A possible association with pulmonary arterial hypertension is also suggested in this case.Misalignment of pulmonary vessels, with or without alveolar capillary dysplasia (ACD), is a rare cause of persistent pulmonary hypertension in the newborn [1–5]. The prognosis is poor, with patients usually succumbing to unremitting hypoxaemic respiratory failure and death in early infancy [3–7]. We report the CT and histological findings of misplaced pulmonary arteries in a previously healthy young adult patient who presented with symptoms of pulmonary arterial hypertension. CT of the chest confirmed the findings of pulmonary arterial hypertension and demonstrated small anomalous pulmonary arteries within many interlobular septa. Surgical lung biopsy confirmed the presence of anomalous muscularised small pulmonary arteries in the interlobular septa. To our knowledge, this is the first reported adult patient with a histological diagnosis of misplaced pulmonary arteries in the literature and may represent a variant of misalignment of pulmonary vessels seen in neonates. This finding lends credence to earlier assertions that the distribution of the vascular misalignment, be it patchy or diffuse, may correlate with the phenotypic expression of disease [3, 6, 7]. The finding in an adult without associated ACD would seem to validate previous hypotheses that the anomalies may co-exist or present as mutually exclusive entities [2–5].