A Case Series of Congenital Alveolar Capillary Dysplasia with New Associations and Literature Review

We report six cases of autopsy proven (unrestricted) ACD- MPV from a single institution during a seven year period (January 2007 to January 2013). Congenital Alveolar capillary dysplasia with misalignment of the pulmonary veins (ACD-MPV) is a rare and a lethal cause of neonatal respiratory failure and severe hypoxemia, secondary to persistent pulmonary hypertension (PPHN). It is refractory to all standard medical therapies including High Frequency Ventilation (HFV), inspired Nitric Oxide (iNO), and Extracorporeal Membrane Oxygenation (ECMO). According to the Online Mendelian Inheritance in Man (OMIM), it is caused by heterozygous mutation in the FOXF1 gene on chromosome 16q24. Newer study has suggested that two other genes can cause (ESRP1) or function as modifiers (PLXNB2) of the ACDMPV phenotype. Most reported cases of ACD-MPV had multiple congenital non-lethal anomalies. Pathology slides were read and confirmed by pediatric pathologists of two different university hospitals. Novel findings include an association with previously undescribed congenital anomalies and a sibling with congenital alveolar dysplasia without capillary dysplasia. All patients presented in the newborn period, with severe hypoxemia and echocardiogram (Echo)-confirmed PPHN. The vast majority of ACDMPV cases continue to be diagnosed by autopsy, after the infants have been subjected to extreme degree of intensive care. ACD-MPV needs to be considered as a diagnostic possibility when ECMO fails.