Congenital absence of pericardium: two cases and a comprehensive review of the literature.

Congenital absence of pericardium (CAP) is a rare condition, generally asymptomatic or paucisymptomatic, nevertheless sporadic cases complicated by sudden death are described. CAP can be diagnosed by CT and MRI. It is classified as total or partial, and partial defects are divided into left defects and right defects. Interestingly, several articles highlight the correlation between CAP and some anatomical lung abnormalities, such as presence of lung parenchyma between the main pulmonary artery and ascending aorta, lung parenchyma between the base of the heart and left hemidiaphragm, and lung parenchyma between the proximal ascending aorta and right pulmonary artery.