Clínica de Diagnóstico por Imagem – CDPI, Rio de Janeiro - Brazil.

Definition

Cystic adenomatoid malformation of the lung is characterized by abnormal proliferation of bronchiolar-like air spaces and a lack of normal alveoli, suggesting interruption of normal cellular development. It is frequently unilateral, limited to one lobe or segment in 95% of cases. Stocker et al (1977) described three types: macrocystic (cysts 2 to 10 cm), lesions with small cysts (< 2cm), and microcystic (cysts < 0,5 cm) with solid appearance.

The differential diagnosis include congenital diaphragmatic hernia, neurenteric cyst and esophageal duplication.

We present ultrasound and MRI images of CCAM in macrocyst form at 27 week’s gestation.

Images 1 and 2: 27th week. Image 1 shows an axial view through the area of cystic adenomatoid malformation of the left fetal lung, type I. Large anechogenic, left-sided lesion (arrow) displaces the heart to the right. Image 2 shows the axial, sagittal and coronal view of the cystic adenomatoid malformation of the left lung.

Images 3, 4: 3D views of the cystic adenomatoid lesion of the fetal lung (arrow).

Images 5 and 6: Image 5 - power Doppler image; transverse scan through the chest showing cystic adenomatoid malformation of the left fetal lung with dextroposition of the heart. Image 6: MRI (T2-weighted, axial view) shows the lesion with high signal intensity (red arrow) and the heart displaced to the right (blue arrow).

Images 7 and 8: MRI (sagittal view) showing the left-sided cysts representing cystic adenomatoid malformation of the lung, type I (arrows).

Image 9: Coronal T2-weighted view shows the high signal intensity cysts (arrow).

Reference

1. Stocker JT, Madewell JE, Drake RM.: Congenital cystic adenomatoid malformation of the lung: classification and morphologic spectrum. Hum Pathol 8: 155, 1977.