Contained ascending aortic rupture disguised as a right atrial mass.

Transesophageal echocardiography can incidentally detect cardiac masses. A right atrial mass has many possible causes, including metastatic extension from various solid organs, malignant melanoma, mediastinal cysts, hematoma, myxoma, lipoma, and artifact.Herein, we report our discovery of a right atrial mass during the initial intraoperative transesophageal echocardiographic examination of a patient who was undergoing repair of an ascending aortic aneurysm. The mass, with a smooth border and homogenous grayscale density, showed no flow during color-flow Doppler echocardiography. Further examination revealed tricuspid annular dilation and severe tricuspid insufficiency. When the mediastinum was opened, we found a large extracardiac hematoma along the right atrium within the pericardial space. These findings suggested an acute, contained rupture of the ascending aorta. After the hematoma was evacuated, imaging revealed complete resolution of the mass and reduction of tricuspid insufficiency. The patient underwent the scheduled aortic repair and was discharged from the hospital in good condition. In order to ensure an accurate diagnosis and to gain appropriate clinical guidance that can lead to a successful outcome, we suggest performing a thorough echocardiographic investigation to identify any such mass before planned surgery proceeds.