Characteristics of congenital cystic adenomatoid malformations associated with nonimmune hydrops and outcome.

Background/purpose: In fetuses with congenital cystic adenomatoid malformations of the lung (CCAMs), hydrops fetalis and large masses are associated with poor outcomes. This study attempts to (1) determine sonographic features (in addition to large size) that correlate with hydrops and (2) characterize the features that correlate with outcome among hydropic fetuses.

Method: Charts and sonograms of fetuses with large, unilateral CCAMs were retrospectively reviewed. Mass features evaluated included laterality, macrocystic/microcystic, cystic/solid predominance, degree of mediastinal shift, retrocardiac component, diaphragm eversion, polyhydramnios, and mass-thorax ratio (MTR). Features of hydrops included degree of ascites, scalp and integumentary edema, pleural/pericardial effusion, and placentomegaly.

Results: Thirty-six fetuses with large CCAMs were studied: 27 with and 9 without hydrops. Three sonographic features were significantly associated with hydrops: MTR of at least 0.56, cystic predominance of mass, and eversion of hemidiaphragm. Of 27 fetuses with hydrops, 10 (37%) demonstrated all 3 features compared with none in those without hydrops (P = .04). All 9 nonhydropic fetuses were expectantly managed, and 100% survived. In the hydropic group, none of the expectantly managed fetuses survived, and 10 (43%) of the 21 fetuses who underwent fetal intervention survived.

Conclusion: Three features of large CCAMs were significantly associated with hydrops: MTR, cystic predominance, and diaphragm eversion. Identification of these features will allow clinicians to accurately predict which fetuses may warrant closer follow-up and possible treatment.