Right Atrial Thrombus Mimicking Myxoma

Abstract

Right atrial mass could be a tumor, thrombus, or vegetation, and it often poses a diagnostic dilemma. Accurate diagnosis is crucial to planning the correct management strategy. However, despite the advanced and sophisticated diagnostic modalities available, differentiating intracardiac masses could still be challenging. Clinical presentation leads to the appropriate conduit of investigations, and histopathology is confirmatory. When the diagnostic dilemma persists even after all efforts, clinical scenario should be strongly reconsidered, especially in unique clinical settings before concluding a diagnosis. In this article, the authors describe the case of a young woman with history of peripheral arterial thrombosis, who underwent surgical excision of a right atrial mass diagnosed as right atrial myxoma. She later presented with massive pulmonary embolism and deep vein thrombosis of the lower limbs. In view of her extensive thrombotic history, her entire case was reviewed including the histopathology slides, and the diagnosis of right atrial thrombus was considered and confirmed. On further workup for thrombotic state, she was found to have protein C deficiency.

Massive Mural Thrombus Masquerading as Myxoma

“…On echocardiography, atrial myxomas typically present as a mobile atrial mass with a distinct narrow stalk usually anchored to the fossa ovalis. Intracardiac thrombi are alternatively usually found on the left atrial appendage, are usually smaller in size, and exhibit less mobility [ 16 ].…”

“…Though there are multiple intracardiac thrombi documented in the literature, there are very few documented over six centimeters in any given dimension [ 3 - 15 ]. An intracardiac thrombus seven centimeters in one dimension is especially rare, as larger sizes usually portend a cardiac tumor [ 16 ]. In addition, the thrombus in our case was located near the interatrial septum, which is unique as most thrombi originate in the atrial appendage.…”

“…In addition, the thrombus in our case was located near the interatrial septum, which is unique as most thrombi originate in the atrial appendage. Also, the thrombus exhibited high mobility, a feature usually found in myxomas [ 16 ].…”

Catheter‑related giant right atrial thrombosis mimicking a myxoma: A case report

“…Echocardiographic features, used to differentiate atrial myxoma from thrombus, are represented by an irregular shape of the thrombus, immobile mass with a broad base attached to the posterior atrial wall in case of in situ thrombi and a spherical, ovoid mobile mass in case of secondary thrombi. Large mobile thrombi may appear to have no attachment to the atrial wall and they may be mistaken for myxoma (13,14).…”