Management of asymptomatic neonatal cystic adenomatoid malformations.

Background/purpose: Although much is known about the prenatal course of cystic adenomatoid malformations (CCAM), the postnatal course of asymptomatic lesion is less well documented. The authors studied the pre- and postnatal course and treatment of asymptomatic CCAM.

Methods: The authors reviewed the files of all patients referred to Necker-Enfants Malades hospital with an antenatal diagnosis of CCAM and asymptomatic at birth.

Results: Files of 29 patients were studied. The first x-ray film was considered normal in 12 cases (41.3%). Computed tomography was normal in 4 cases and showed cystic lung malformations in the other patients. Postnatally, clinical manifestations occurred in 3 patients (10.3%). CCAM vanished in 6 cases. Surgical resection of CCAM was performed in 17 cases (58.6%). All the patients currently are asymptomatic.

Conclusions: CCAM can shrink or vanish during pregnancy and antenatal ultrasound findings are not predictive of the postnatal course. Thus, all infants with prenatal diagnosis of CCAM require postnatal evaluation. Normal radiographic findings at birth do not rule out CCAM persistence on CT. The treatment of asymptomatic CCAM is controversial. Surgery may be advocated because of the low morbidity and the prevention of late complications, above all, cancer. The surgical indications of small (<3 cm) and asymptomatic lesions should be discussed on a case-by-case basis with the parents.