Congenital cystic adenomatoid malformation: is there a difference between the antenatally and postnatally diagnosed cases?

Background: The majority of congenital cystic adenomatoid malformation (CCAM) lesions are diagnosed antenatally. A few cases however may not be recognised antenatally and present in infancy or later childhood with chest symptoms, including chest infection. Objective: To review the clinical and radiological spectrum of CCAM, comparing the antenatally with the postnatally diagnosed cases. Materials and methods: Fifteen cases of antenatally and/or postnatally diagnosed and histopathologically proven CCAM were retrospectively identified over a period of 4 years. Clinical notes, chest radiograph and chest CT were reviewed in all cases. Results: Nine patients were diagnosed antenatally and six postnatally. All antenatally diagnosed patients were asymptomatic at birth, six remained asymptomatic until they had elective surgery and the remaining three developed symptoms before the age of 2 years. In the postnatally diagnosed group, one patient was symptomatic at birth and one patient presented at 16 years; the remaining four presented before the age of 2 years. Depending on the type of lesion, we recognised five radiographic patterns of CCAM. CCAM lesions were classified as CT Stocker type I in seven cases, type II in seven cases and type III in one case. Conclusions: No significant difference was found between the two groups. Recognition of these lesions antenatally would benefit patients by avoiding delay in making the diagnosis, which can lead to serious complications. CT was successful in accurately diagnosing and grading CCAM lesions.