Challenging antenatal differential diagnosis of a congenital lung malformation. A case report of a hybrid lesion: congenital pulmonary airway malformation type II and bronchial atresia

We herein report on the antenatal to postnatal management of a right congenital lung malformation diagnosed in a fetus of 22 weeks of gestation. We discuss the prenatal diagnosis based on second trimester morphologic ultrasound and magnetic resonance imaging (MRI) findings at 28 weeks, in addition to the neonate’s birth, immediate evaluation at day 1 of life, examination by computed tomography (CT) at 3 months, as well as treatment using lobectomy at 4.5 months, and eventually histological diagnosis, in favour of a hybrid lesion consisting of a congenital pulmonary airway malformation (CPAM) type 2 and bronchial atresia. Based on the coexistence of lesions, they likely represent a spectrum of abnormalities originating from a common pathogenic mechanism rather than a differential diagnosis. This spectrum of abnormalities is thought to be secondary to in-utero airway obstruction, with the resulting pathology being dependent on the obstruction level, degree, and timing. A review of recently published literature to try to understand this common pathogenic mechanism is additionally presented.