Cystic adenomatoid malformation of the lung: an obstetric and ultrasound perspective

Prenatally diagnosed fetal lung lesions with associated conotruncal heart defects: Is there a genetic association?

Congenital lung malformation can easily be diagnosed by prenatal ultrasound. Associated extrapulmonary malformations such as heart defects and chromosomal aberrations are rare.

OBJECTIVE

The objective of this study was to describe the natural history, outcome and other associated malformations in fetuses with lung lesions and an associated heart defect.

METHODS

Retrospective analysis of 4 cases of prenatally diagnosed fetal CCAMs and hybrid lesions with an associated heart defect and review of 8 cases in the literature.

RESULTS

At a single referral center 1.9% of the fetuses with Congenital cystic adenomatoid malformation (CCAM) were diagnosed with an associated heart defect. Seven of the total 12 cases (58%) reviewed had a conotruncal heart abnormality. Chromosomal abnormalities were found in 5 (42%) of the cases.

CONCLUSION

This retrospective review shows that karyotyping in fetal lung lesions with an associated heart defect or isolated large lung lesions is indicated. It also suggests that there is a subpopulation of fetuses with CCAMs who have conotruncal heart defects. This finding may suggest a common genetic background.

Prenatal diagnosis of partial trisomy 1q and monosomy X in a fetus with a congenital lung lesion and hydrops fetalis

We report on the prenatal diagnosis of partial trisomy 1q and monosomy X in a fetus with a congenital lung lesion and hydrops. The finding of hydrops in a fetus with a small lung lesion, congenital cystic adenomatoid malformation (CCAM) volume to head circumference ratio (CVR) 0.78, prompted cytogenetic analysis of amniotic fluid, revealing an unbalanced translocation between chromosomes X and 1 [46,X,der(X)t(X;1)(p11.2;q25 or q31)]. The incidence of chromosomal abnormalities with CCAM lesions is estimated at 1.6%. This is the first reported case of prenatally diagnosed partial trisomy 1q and monosomy X presenting as a fetal lung lesion and hydrops.

Unusual case of a fetus with congenital cystic adenomatoid malformation of the lung associated with trisomy 13

Congenital cystic adenomatoid malformation of the lung can be detected with antenatal ultrasound as hyperechogenic areas in the fetal chest. Associated extrapulmonary malformations as well as chromosomal aberrations are described as very rare. We present a case report of a fetus in the 23rd week of gestation who showed in the course of a routine ultrasound screening a large number of malformations: holoprosencephaly, arrhinencephaly, cleft palate, CCAM type III of the right inferior pulmonary lobe, ventricular septal defect and bilateral clubfeet. Chromosome analysis confirmed the suspicion of trisomy 13. The present case shows how important it is-even with malformations that are rarely accompanied by associated anomalies and which have a very good prognosis-to carry out a directed diagnosis including a fetal karyotyping.

Noncardiac thoracic anomalies

FHT is a rare diagnosis that may be an isolated finding or associated with multiple fetal anomalies, congenital infection or isoimmunization. The natural history of the lesion is variable. The effusion may regress spontaneously; remain stable in size; or progress to involve both sides of the chest and produce fetal hydrops, pulmonary hypoplasia, and fetal or neonatal demise. Hydrops is associated with significant fetal mortality. Antenatal decompression of the hydrothorax with pleuroamniotic shunting or thoracocentesis may result in a significant decrease in perinatal morbidity and mortality. Persistent hydrothorax can usually be treated with noninvasive measures in the newborn period.

Prenatal ultrasound diagnosis of congenital cystic adenomatoid malformation of the lung: a report of 26 cases and review of the literature

OBJECTIVES

To evaluate the sonographic appearances and prenatal natural history of congenital cystic adenomatoid malformation of the lung.

METHODS

In each case a detailed examination of the thoracic lesion and a complete fetal survey was performed. The pregnancies that elected to continue were followed to term.

RESULTS

A total of 26 cases were identified. The pregnancy was electively terminated in nine cases (35%). All the remaining 17 pregnancies ended in liveborn infants (100%). The lesion disappeared completely in three fetuses (18%). Of the 14 infants in whom the lesion was confirmed at birth nine required surgery in the neonatal or post-natal period. Five children did not undergo surgery.

CONCLUSIONS

Conservative management appears to be an adequate medical practice in cases of isolated congenital unilateral cystic adenomatoid malformation of the lung, in the absence of hydrops and/or acute polyhydramnios.

The prognostic factors in the prenatal diagnosis of the echogenic fetal lung

The prenatal diagnosis of an echogenic fetal lung (EFL) is now often made in the early second trimester using high-resolution ultrasound. This ultrasound appearance is usually caused by a congenital cystic adenomatoid lung malformation (CCAM), an intrapulmonary lung sequestration or obstruction of a major airway. In order to provide prognostic guidelines to parents who may be considering termination of a fetus with these findings, we have analysed a series of 11 cases diagnosed in our centre over the past 2 years in conjunction with 60 cases from major published series. The data suggest that in the absence of non-immune hydrops fetalis (NIHF) or other anomalies, the outcome for the fetuses is excellent, with over 90 per cent survival. Neither early diagnosis (24 weeks) nor the presence of mediastinal shift is a poor prognostic indicator. In addition, it appears that if NIHF is absent at diagnosis, the chance that it will develop as the pregnancy continues is small (6 per cent). Furthermore, there is a significant (up to 30 per cent) chance that this ultrasound finding will resolve in utero. The development of in utero fetal surgical techniques may be the only hope for those hydropic fetuses who appear to have a dismal prognosis.

Cystic adenomatoid malformation of the lung: prenatal diagnosis and outcome

During an 8-year period (1984-1992), we made the ultrasonographic diagnosis of cystic adenomatoid malformation (CAM) of the lung in 58 fetuses at 17-39 weeks' gestation. We reviewed the records of these fetuses and combined the data from 74 cases reported in the literature to determine the incidence of the different types of CAM, associated malformations, and outcome. The lesions were macrocystic in 78 (59 per cent) and microcystic in 54 (41 per cent) of the cases. CAM was left-sided in 51 per cent, right-sided in 35 per cent, and bilateral in 14 per cent of the fetuses. In 15 (11 per cent) of the fetuses there were additional malformations and 57 (43 per cent) were hydropic. The pregnancy was electively terminated in 44 (33 per cent) of the cases, including all those with bilateral CAM. There were six (5 per cent) intrauterine deaths, five in association with hydrops, and one with growth retardation and heart defect. Of the 82 (62 per cent) infants that were liveborn, 21 (26 per cent) died in the neonatal period, 15 before and six after surgery. Of the 61 survivors, 16 (26 per cent) did not require surgery. In the 88 cases where the pregnancy was not terminated, survival was better if the CAM was macrocystic (74 per cent versus 58 per cent for microcystic), if there was no hydrops (92 per cent versus 21 per cent for hydrops), and if the amniotic fluid volume was normal or decreased (82 per cent versus 53 per cent for polyhydramnios).

Congenital cystic adenomatoid malformation of the lung: prenatal management and prognosis

Thirty-two cases of congenital cystic adenomatoid malformation of the lung diagnosed antenatally are reported. Antenatal diagnosis has made it possible to document the progress of the condition in utero and the postnatal prognosis. It has been possible to advise on termination and intrauterine intervention, to counsel the parents, and to plan arrangements for delivery and postnatal care among obstetricians, neonatologists, and pediatric surgeons. According to Stocker's classification there were 12 cases of type I, 15 of type II, and 5 of type III. Five pregnancies were terminated. Antenatal drainage of a cyst was performed in four patients with two survivors. Thirteen babies showed relative regression of the cyst as pregnancy progressed. After delivery the extent of the cystic malformation was assessed by chest x-rays and computed tomography scanning in 25 and angiography in 6. Treatment consisted of observation in 4, embolization in 2, operation as an emergency in 3, and electively around 4 months in 15.

Disappearing lung echogenicity in fetal bronchopulmonary malformations: a reassuring sign?

Congenital bronchopulmonary malformations detectable on prenatal ultrasound include cystic adenomatoid malformation (CAM), lobar sequestration, and upper airway atresia. We describe three fetuses with prenatally detected intrathoracic lesions in which the associated pulmonary hyperechogenicity disappeared before delivery. In the first case of pulmonary sequestration, the infant was asymptomatic after birth. However, in a case of CAM and another with laryngeal atresia, respiratory distress developed after delivery, despite recent scans showing apparently normal lung fields. This experience suggests that ultrasonic resolution of hyperechogenic lung lesions in utero does not necessarily indicate resolution of the underlying pathology.

Fetal surgery for cystic adenomatoid malformation of the lung

We reviewed our experience with fetal therapy for congenital cystic adenomatoid malformation of the lung (CCAM) at the University of California, San Francisco Fetal Treatment Center. Fetuses with life-threatening CCAM were selected for prenatal treatment according to predetermined guidelines, including the gestational age of the fetus, the size of the intrathoracic lesion, maternal health, and the development of fetal hydrops. The knowledge that fetuses with hydrops are at high risk for fetal or neonatal death led to fetal surgical resection of the massively enlarged pulmonary lobe (fetal lobectomy) in six cases. In the first case, resection was too late, since preoperative labor and maternal preeclampsia could not be reversed, leading to premature delivery of a nonviable infant. In the next four cases, CCAM resection led to resolution of the hydrops, impressive in utero lung growth, and neonatal survival. Right middle and lower lobe resection in the sixth fetus at 21 weeks was successful, but subsequent inexplicable fetal death highlights the need for better postoperative fetal monitoring and treatment. Three other fetuses with a single predominant cyst underwent thoracoamniotic shunt placement alone; two survived after delivery and prompt neonatal surgery with the assistance of high-frequency ventilation or extracorporeal membrane oxygenation. Fetal therapy can now be considered for otherwise fatal space-occupying intrathoracic lesions in the fetus.