Right Atrial Mass, A Rare Diagnostic Dilemma

C. D. Kang, University of Nevada, Las Vegas
J. Choa, University of Nevada, Las Vegas


Right atrial mass is rare, and management varies based on the etiology. We present a case of a right atrial mass that posed an unusual diagnostic dilemma. A 75 year-old man with PMH of CHF, COPD, and PE 3 months ago with anticoagulation noncompliance who presented with few weeks of shortness of breath and decreased exercise tolerance. There was no fever, cough, chest pain, PND, orthopnea, or intentional weight loss. Vital signs showed he was afebrile, HR 75, BP 123/70, RR 23, saturating at 95% on room air. Physical exam showed diminished breath sound in bibasilar lung bases. There was no peripheral edema. Bedside TTE revealed new right atrial mass measuring 4 x 2cm possibly in transition to the right ventricle. Patient was admitted to CCU and started on heparin drip. TEE showed large mass with fingerlike projections encompassing majority of right atrium and protruding into the right ventricle, and that origin of mass appears to come from pedunculated stalk off IVC. CT A/P showed no mass. Surgery to retrieve the right atrial mass was then done. Cardiopulmonary bypass and bicaval cannulation were performed. Right atrium was opened and explored, without visualization of the mass. Further exploration was made into right ventricle, main pulmonary artery, and bilateral pulmonary arteries, with finding of only a 1-2cm thrombus-liked mass in the right pulmonary artery which was retrieved. Although no mass that commensurate to the size that was on TEE was found, it was thought that the inferior venous return during cardiopulmonary bypass had sucked out the thrombus for the most part. The mass that was able to be retrieved was sent to pathology, which confirmed it to be thrombus, without features of malignancy. Postoperative course was uncomplicated, and patient was discharged on warfarin. Right atrial (RA) mass is an uncommon finding, and the incidence of which has not been well-studied. It carries a broad differential diagnosis, which includes benign or malignant tumors, vegetation, or thrombus. It is easily detected by echocardiogram, however, the composition of the mass is often difficult to differentiate. Management also widely differs based on the etiology. Right atrial thrombus is also a rare entity itself, and can progress to fatal PE if undiagnosed. Our case not only highlights the diagnostic dilemma that RA mass presents, but also reminds us how the changing intraoperative hemodynamics during cardiopulmonary bypass could present another challenge in the search for its cause.