What is it?
Congenital cystic adenomatoid malformation (CCAM)
Cystic hamartomas of the distal bronchioles
Communicates with bronchial tree
Characterized by size and number of cysts
Pulmonary hypoplasia possible from compression
Type 1 (50% of cases) includes multiple large cysts (>2 cm in diameter) or a single large cyst surrounded by numerous smaller cysts. Adzick et al: Macrocystic lesions (ie, cysts >5 mm) were not usually associated with hydrops and had a good prognosis.
Type II (40%) multiple small cysts, usually less than 1 cm in diameter. In Stocker's series, the type II lesion was particularly associated with other lesions, specifically renal agenesis.
Type III (<5% ) multiple microcysts, measuring less than 0.5 cm in diameter.
In 1993, Adzick reported his group system of classification. Microcystic lesions (cysts measuring <5 mm) were usually associated with fetal hydrops and, hence, a poor prognosis.
Typically present in 1st 6 months of life with respiratory distress
May be found on prenatal ultrasound
Large lesions may cause intrauterine demise
Can be associated with other malformations, so Cranial, renal u/s and echo recommended
plain films may show mediastinal shift or air/fluid levels
CT will show cystic lesions
Treatment is surgical excision
Potential for malignant transformation if not resected
eMedicine.com: Cystic Adenomatoid Malformation. Last Updated: November 15, 2002
Adzick NS, Harrison MR, Crombleholme TM, Flake AW, et al: Fetal lung lesions: management and outcome. Am J Obstet Gynecol 1998 Oct; 179(4): 884-9
Stocker JT, Madewell JE, Drake RM: Congenital cystic adenomatoid malformation of the lung. Classification and morphologic spectrum. Hum Pathol 1977 Mar; 8(2): 155-71