Prenatal diagnosis of congenital cystic adenomatoid malformation and its postnatal presentation, surgical indications, and natural history

Background/Purpose: Regression of a cystic adenomatoid malformation (CAM) i n a fetus is well described. Little, however, is known about the postnatal course of these infants. This study attempts to correlate the prenatal cour se of CAMs with postnatal symptoms, radiological manifestations, and need f or surgery. Methods: The clinical course of patients with a CAM diagnosed prenatally we re retrospectively reviewed. Inclusion in the study required a prenatal ult rasound scan documenting a CAM. Results: Over 10 years, 14 patients with a CAM were diagnosed prenatally. S ix (43%) showed a partial in utero regression. Four patients were symptomat ic at birth and underwent a resection as newborns. Ten patients were asympt omatic at birth, and eight of these had normal chest x-rays. Elective resec tion has been performed in 3 of these 10, and two additional children are s cheduled to undergo an excision near 1 year of age. The remaining five pati ents have undergone follow-up nonoperatively for a mean of 36 +/- 15 months . Of the seven asymptomatic patients not undergoing immediate surgery, only one has shown a slight postnatal regression, despite five of these showing regression in utero. None have become symptomatic. Conclusions: The results suggest that regression of a CAM on prenatal ultra sound scan is common, but this process does not continue after birth. A nor mal chest x-ray does not indicate complete regression of a CAM; a computed tomography (CT) scan is required to evaluate such patients, and will genera lly demonstrate a CAM. Asymptomatic patients with a CAM may be followed up nonoperatively with no apparent adverse effects. The decision and timing of an excision in an asymptomatic patient remains controversial among pediatr ic surgeons. Copyright (C) 1999 by W.B. Saunders Company.