Outcome of the prenatally diagnosed congenital cystic adenomatoid lung malformation: a Canadian experience

Abstract

Congenital cystic adenomatoid malformation of the lung (CCAM) is diagnosed by prenatal ultrasonography with an increasing frequency but controversy persists as to its prognosis and prenatal management.

Method: A multi-institutional study of cases of CCAM diagnosed antenatally identified by ultrasonographers and by a review of hospital charts.

Results: We obtained 48 cases from five centers. We estimate the incidence of CCAM at 1:25,000 to 1:35,000 pregnancies. The incidence of voluntary abortions was 15% (7/48), of spontaneous abortions 2% (1/41) and of postnatal death 10% (4/40). One of the postnatal deaths was from trisomy 18. Of the 7 aborted fetuses, 2 had multiple malformations and 1 had severe hydrops and oligohydramnios; the other 4 had a large mass with mediastinal displacement but without hydrops. When pregnancy was allowed to continue, 56% of the lesions regressed spontaneously, even though one third of these had initial progression. In 17 cases (42%) the mediastinal shift corrected itself, sometimes by simple growth of the fetus but most often by a decrease in the size of the lung mass. In 1 fetus, repeated needle decompressions followed by double-pigtail catheter drainage of large cysts allowed regression of hydrops. Despite this, neonatal death occurred from pulmonary hypoplasia.

Conclusion: CCAM can lead to fetal or neonatal demise from hydrops, lung hypoplasia, prematurity or severe associated malformations, but has a good prognosis in the majority of cases.