[Adenomatoid malformation as peripheral round shadow in lung].

The authors present a case report of a 17 years old female patient who had a peripheral round shadow on the chest X-ray. After the operation the histological examination verified cystic adenomatoid malformation. The cystic adenomatoid malformation is an abnormal growth of the terminal bronchiolar structures. It is a rare disease, but often associates with other developmental abnormalities. It is important in the differential diagnosis to separate this disease from other cystic pulmonary lesions or sequestration. It is usually recognized in antenatal period or early childhood, but rarely in adulthood. It is possible that there is a connection between the adenoid malformation and lung cancer.