Congenital cystic adenomatoid malformation in adults: Report of a case presenting with a recurrent pneumothorax and a literature review of 60 cases

Congenital cystic adenomatoid malformation (CCAM) is a congenital pulmonary cystic disease that is mostly detected and diagnosed prenatally or during the neonatal period, while rarely being observed in adults. Here, we report an adult case of CCAM that was diagnosed following surgery for a recurrent pneumothorax. We further review 60 case reports on adult CCAM that have been previously published. The patient was a 29-year-old woman with a severe left pneumothorax. Her computed tomography scan showed the presence of multiple pulmonary cysts at the base of the left lower lobe. Since she had experienced a left pneumothorax twice previously, surgery was indicated. A wedge lung resection of the pulmonary cysts was performed thoracoscopically. The postoperative pathological diagnosis was type I CCAM. From the review, 7 adult CCAM patients (11.7%) out of 61, including the patient in the present case, presented with pneumothorax, while 21 patients (35%) presented with infection. Thirty-nine foci of CCAM (65%) were located in lower lobes. Moreover, malignancies were associated in 8 cases (13.3%). We propose that if multicystic lung lesions are found in pneumothorax patients, particularly in lower lobes, CCAM should be considered during the differential diagnosis, even in adults.