Case report
 
A 30-year-old woman (G2P1) was referred to our antenatal unit at 23 weeks of pregnancy for a sonographic examination. There was no known family history of congenital disease. The patient didn’t take any medications. During our examination we discovered an isolated cystic structure within the right fetal thorax (images 1, 2) – the structure stayed of the same size when compared during the next examination at 25 weeks (images 3, 4, 5, and 6). The pulmonary artery and aorta seemed normal and the heart had normal four-chambered morphology. No feeding vessels of the lesion were found (image 9) and thus the lung sequestration was excluded and the diagnosis of congenital cystic adenomatoid malformation type I was assumed. The size of the cyst at 30 weeks was identical.

The parents opted for the continuation of the pregnancy. Amniocentesis revealed normal karyotype. At 32 weeks MRI was done and confirmed the diagnosis of the cystic adenomatoid malformation type I (images 10, 11, 12, and 13). After birth the diagnosis was also confirmed.

Images 1, 2: 23 weeks; isolated cystic structure within the right thorax consistent with the cystic adenomatoid malformation type I can be seen.

Images 3, 4: 25 weeks; isolated cystic structure within the right thorax consistent with the cystic adenomatoid malformation type I can be seen.

Images 5, 6: 25 weeks; isolated cystic structure within the right thorax consistent with the cystic adenomatoid malformation type I can be seen.

Images 7, 8: Images show transverse scan of the fetal thorax at the level of the four-chamber view of the heart with the cystic lesion within the right thorax.

Image 9: No feeding vessels of the cystic lesion were found.

Images 10, 11: MRI images showing the cystic lesion within the right fetal thorax.

Images 12, 13: MRI images showing the cystic lesion within the right fetal thorax.

Images 14, 15: Postnatal X-ray showing the cystic leasion within the right hemithorax.

Video 1: The video summarises the anomalies described above.