Perinatally diagnosed asymptomatic congenital cystic adenomatoid malformation: to resect or not?

BACKGROUND: Management of asymptomatic congenital cystic adenomatoid malformation (CCAM) is controversial. The natural history of untreated asymptomatic CCAM is unknown, although most surgeons recommend resection of these lesions to prevent future infection. The aim of this study was to determine the relative surgical risk of resection compared with the risk of observation for these patients. METHODS: A retrospective review of hospital records between 1996 and 2002 in a tertiary care pediatric referral center was conducted. All perinatally (prenatal or neonatal) diagnosed CCAMs were included. In addition, patients presenting with late diagnosis of CCAM were also reviewed. RESULTS: Forty-eight children had CCAM diagnosed perinatally. Thirteen of these were symptomatic and required surgery within 6 months; these were excluded from the analysis. Of the 35 asymptomatic infants, 6 were operated on electively before 6 months of age (median age, 4.5 months). The other 29 asymptomatic infants were followed up for more than 6 months. Of these, 9 remained asymptomatic and were eventually operated on electively (median age, 13 months). Three (10%) had CCAM infections at 7, 8, and 11 months of age and required resection. The remaining 17 children have not undergone resection and are still asymptomatic (median follow-up, 3 years). An additional 12 patients presented with a late diagnosis of CCAM. All of these presented with complications (infection or pneumothorax) and underwent resection (median age, 6 years). Overall, the complication rate after resection of an asymptomatic CCAM was not significantly different from those of resected CCAM that had already developed infection or pneumothorax (P =.64). CONCLUSIONS: Ten percent of perinatally diagnosed asymptomatic patients had 5 complications requiring surgery during follow-up. The true incidence is probably higher given the relatively short follow-up in our series. Morbidity after resection of a complicated CCAM was not statistically significantly higher than after elective resection for an asymptomatic CCAM. Although conservative management of asymptomatic CCAM may be warranted, a more extended period of follow-up is necessary before this approach can be recommended.