Outcome of antenatally suspected congenital cystic
adenomatoid malformation of the lung: 10 years’
J K Calvert, P A Boyd, P C Chamberlain, S Said, K Lakhoo
............................................................... ............................................................... .
See end of article for
Dr Calvert, Neonatal Unit,
John Radcliffe Hospital,
Oxford OX3 9DU, UK;
Accepted 29 June 2005
Published online first
30 August 2005
Arch Dis Child Fetal Neonatal Ed 2006;91:F26–F28. doi: 10.1136/adc.2004.068866
Objective: To determine the outcome of antenatally suspected congenital cystic adenomatoid malformation
of the lung (CCAM) over a 10 year period.
Methods: This is a retrospective study of all babies diagnosed antenatally in the Prenatal Diagnosis Unit
and delivered in Oxford between 1991 and 2001. Data were obtained from the Oxford Congenital
Anomaly Register, theatre records, and histopathology reports.
Results: Twenty eight cases of CCAM were diagnosed antenatally. Five pregnancies were terminated.
Data are available on all 23 of the pregnancies that continued and resulted in two neonatal deaths and 21
surviving babies. Eleven of the 23 cases (48%) showed some regression of the lesion antenatally, and four
of these cases appeared to resolve completely on prenatal ultrasound. Three of the 23 babies (13%) were
symptomatic in the early neonatal period, and three developed symptoms shortly afterwards. Seventeen of
the 23 babies (74%) were asymptomatic, of whom 12 had abnormalities on chest radiograph or computed
tomography scan and had elective surgery. Two babies (8%) had completely normal postnatal imaging,
and three had abnormalities which resolved in the first year of life. Seventeen of the 23 babies (74%) had
surgery. Histology at surgery was heterogeneous. Of the 23 live births, all 21 survivors (91%) are well at
follow up or have been discharged.
Conclusions: All babies diagnosed antenatally with CCAM require postnatal imaging with computed
tomography irrespective of signs of antenatal resolution. In asymptomatic infants, the recommendations
are close follow up and elective surgery for persistent lesions within the first year of life. Histology at
surgery was heterogeneous, and this should be considered when counselling parents.
ment.1–3There has been an increase in cases suspected
prenatally over the last decade. Antenatal ultrasound find-
ings suggestive of CCAM include an increase in lung
echodensity with or without associated cyst formation.
Hydrops may occur in the most severe cases. The differential
diagnosis includes lobar sequestration or congenital dia-
CCAM is usually restricted to a single lobe and occurs in
isolation.7Associated anomalies are rare. An incidence of 1 in
25 000 live births has been suggested,8with males and
females equally affected. Potential clinical outcomes asso-
ciated with CCAM are as follows. Antenatally it can lead to
hydrops, polyhydramnios, or regress.9Postnatally the baby
may have severe respiratory distress, or more commonly be
asymptomatic.8 10–13Traditionally, surgery is recommended to
remove the CCAM because of the long term risks of morbidity
from infection, pneumothorax, or, more rarely, malig-
The aims of this study were to document the outcome of all
babies diagnosed antenatally with suspected CCAM over a 10
year period from 1991 to 2001 in order to facilitate
counselling of parents during pregnancy and to allow optimal
timing of postnatal management.
ongenital cystic adenomatoid malformation of the lung
(CCAM) is a form of congenital cystic lung disease
believed to result from an arrest in fetal lung develop-
A retrospective audit was carried out of all babies diagnosed
in the Prenatal Diagnosis Unit and delivered at the John
Radcliffe Hospital, Oxford between 1991 and 2001. Data were
obtained from the Oxford Congenital Anomaly Register,
theatre records, and histopathology reports, to identify all
babies with a diagnosis of CCAM. Information on gestation at
diagnosis, progression of the lesion during pregnancy, the
presence of other anomalies, postnatal features, results of
postnatal investigations, and outcome were recorded. Ethical
permission was not required for this study.
Figure 1 illustrates the overall results of the study. Of the
pregnancies that continued, data are available on all 23
babies, two of whom died in the neonatal period and 21 are
alive and well. Table 1 shows the characteristics of these 23
babies. All 21 babies who survived had postnatal imaging
with chest radiograph and computed tomography (CT) scan.
After delivery, three babies were symptomatic, and three
developed symptoms later in the first year of life at 2 weeks, 8
weeks, and 5 months. There were two neonatal deaths: one
baby previously noted to have massive ascites which resolved,
born at 36 weeks gestation with a type 3 CCAM, on the right,
who died at 2 hours of age and was found at post mortem
examination to also have right bronchial atresia and a
hypoplastic left lung; the second baby was born at 35 weeks
gestation and had a large CCAM with hydrops. Despite
surgery, he died on day 9 with complications from multiple
Seventeen babies (74%) were asymptomatic after birth. Of
these, 12 (71%) had abnormalities which were detectable on
postnatal imaging and went on to have elective surgery. Two
babies had their diagnosis changed on the basis of postnatal
Abbreviations: CCAM, congenital cystic adenomatoid malformation of
the lung; CT, computed tomography
imaging to lobar sequestration and a bronchogenic cyst
respectively. Five of the 17 asymptomatic babies (29%) did
not require surgery. Of these five babies, two had chest
radiograph and CT scans reported as normal in the postnatal
period, one baby had a normal chest radiograph and an area
of volume loss on the CT scan, but no identifiable
abnormality, and two babies had normal chest radiograph
and changes on CT scan, which resolved by 9 months of age.
Four of these five babies were followed up for 12–17 months
and were well at discharge.
Overall, 17 babies had surgery. Sixteen of these survived.
Timing of surgery ranged from two days to 23 months with a
median of eight and a half months. Histology from surgery
was heterogeneous. There were nine cases of isolated CCAM,
two of adenomatoid changes within a sequestered lobe, one
bronchogenic cyst which had been diagnosed on postnatal
magnetic resonance imaging scan at 5 months of age, three
cases of isolated lobar sequestration, one of which was
diagnosed on postnatal CT scan, and two cases where the
histology was of bronchial malformation, not typical of either
CCAM or sequestration, with areas of collapse and air
All 21 survivors (91%) are well at follow up or have been
discharged from hospital follow up at between 1 and 3 years
28 cases of suspected
antenatally in Oxford
early in first
All 5 survived
All (4) had
1 35/40 hydrops
2 cases 1 case
1 trisomy 21
3 large CCAM with
diagnosis of congenital cystic
adenomatoid malformation of the lung
(CCAM). TOP, Termination of
Outcome of antenatal
diagnosis of congenital cystic adenomatoid malformation
of the lung
Characteristics of babies born after antenatal
Birth weight (g)
Complete antenatal resolution
Values are median (range) or number (%) (n=23).
Congenital cystic adenomatoid malformation of the lungF27
CCAM is an important diagnosis that can be suspected on
routine antenatal ultrasound. It has implications for both the
ongoing pregnancy and the baby, at delivery and later in life.
Although the prognosis is generally good, this study
illustrates the spectrum of potential outcome for babies with
this diagnosis, ranging from hydrops and severe respiratory
distress with pulmonary hypoplasia, to resolution of the
lesion either antenatally or postnatally. In this study, as
noted by others,13 19a poor outcome was associated with the
presence of hydrops and prematurity. It is important that,
when this diagnosis is made antenatally, parents are made
aware of all potential outcomes and the need for ongoing
surveillance in the pregnancy. Ultrasound scanning is
subjective, and the findings often non-specific and therefore
follow up scanning is important both to confirm a diagnosis
and to document any changes in appearances of the lesion.
Although some lesions do resolve antenatally and most
babies are asymptomatic at birth, we would recommend that
all babies are investigated in the neonatal period with CT
scan, even if the lesion appeared to resolve completely
antenatally. We document two cases of complete antenatal
resolution with normal postnatal investigations, and two
cases in which, although the CCAM was not seen late in
pregnancy, postnatal investigations confirmed the initial
diagnosis. It is also important to distinguish where possible
CCAM from lobar sequestration on postnatal imaging to
ensure optimal management.
Most lesions do persist in the first year of life and therefore
surgery is recommended. However, we have documented
three cases in which abnormalities on postnatal imaging
resolved by 9 months of age. We would therefore advocate a
close follow up of asymptomatic babies, with repeat imaging
and surgery for persistent lesions within the first year of life.
If symptoms develop at any stage, surgery would need to be
The histology at surgery was variable, with some babies
having their diagnosis changed to lobar sequestration. This
should be considered when counselling parents antenatally.
The non-specific term congenital lung malformation may be
more useful when discussing the diagnosis with parents
antenatally, as has been suggested by Bush.20
In conclusion, this paper provides valuable information for
parents and recommendations for timing of surgery in
asymptomatic patients diagnosed antenatally with CCAM.
We acknowledge Dr Mary Anthony for her support and guidance for
J K Calvert, Neonatal Unit, John Radcliffe Hospital, Oxford OX3 9DU,
P A Boyd, National Perinatal Epidemiology Unit, University of Oxford,
Oxford OX3 7LF
P C Chamberlain, Prenatal Diagnosis Unit, Women’s Centre, John
S Said, K Lakhoo, Department of Paediatric Surgery, John Radcliffe
Competing interests: none declared
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What is already known on this topic
N Congenital cystic adenomatoid malformation is a
congenital abnormality of the lung believed to result
from an arrest in fetal lung development
N There is a spectrum of outcomes associated with this
What this study adds
N Most cases persist and are present after birth, although
most babies are asymptomatic
N In those cases where the lesion persists, surgery is
required to remove the abnormality because of the
long term risks of infection, pneumothorax, and, more
F28Calvert, Boyd, Chamberlain, et al