Huge mass bordering on left atrium raises coronary artery
A 45 year old carpenter with an abnormal chest radiograph was referred to us. Computed tomographic (CT) chest scan showed a round mass, 7.5 cm in diameter, bordering on the left atrium with patchy calcification around it. Density inside was almost homogeneous and no effect of the enhancement was observed. Three dimensional reconstruction from the CT showed that the left circumflex artery was raised by the mass and its proximal side dilated (lower panels, left and centre). Coronary angiography did not detect any feeding artery to the mass, and laboratory tests including tumour makers showed no abnormality. The mass was surgically enucleated.
Histological study revealed the mass to be an encapsulated pseudocyst beneath the pericardium and contained the old thrombus (lower panel, right). The precise mechanism of this thrombus formation was unknown, but might be related to blunt trauma received during the patient’s work.
