Spontaneous regression of congenital cystic adenomatoid malformation of the lung: longitudinal examinations by magnetic resonance imaging.

We report a case of large cystic adenomatoid malformation of the lung (CCAM), which occupied almost the entire left lung with a prominent mediastinal shift at 24 weeks of gestation. The volume of the lesion, determined by magnetic resonance imaging (MRI), was 27.0 cm3. Subsequent MRI and ultrasound examinations revealed a spontaneous resolution of the lesion at 32 and 36 weeks of gestation without a mediastinal shift, when the lesion volume was 12.8 cm3 and 5.6 cm3, respectively. At 37 weeks of gestation, a mature male baby weighing 2638 g with an Apgar score of 7 was delivered by elective cesarean section. A lobectomy of the left upper lobe of the lung was carried out at 3 days of age, due to an enlargement of the CCAM after birth.