Atypical antenatal presentation of an unusual nonmucinous papillary variant of giant congenital pulmonary airway malformation masquerading as congenital diaphragmatic hernia with volvulus

We report a case of a huge congenital pulmonary airway malformation (CPAM) that was referred as congenital diaphragmatic hernia (CDH). Initial ultrasound evaluation revealed a huge cystic lesion with septations, in the thorax, causing mediastinal shift and compression effects, suggesting the possibility of a thoracic lymphangioma, or bowel herniation with obstruction. A fetal magnetic resonance imaging reported possible bowel herniation through a posterior defect in the diaphragm, with volvulus, reinforcing the diagnosis of CDH. It was only on autopsy and subsequent histopathology examination that the diagnosis of a rare variant of CPAM–nonmucinous papillary type, could be made. To the best of our knowledge, a CPAM this huge has not been reported prenatally at this gestation. We recommend considering the potential diagnosis of CPAM in any thoracic cystic irrespective of its size or appearance.