Left atrial appendage myxoma masquerading as left atrial appendage thrombus

Abstract

Myxomas are the most common benign tumors of the heart. They can arise from any heart chamber, but have rarely been described as originating from the left atrial appendage. We describe a case of left atrial appendage myxoma mimicking a left atrial appendage thrombus, and presenting with microembolization to the coronaries.

Left atrial appendage myxofibrosarcoma: A rare masquerader of myxoma and thrombus—“all that glitters is not gold”

“…4,5 In our reported case, on CMR, this eventually pathology-defined myxofibrosarcoma could be seen to prolapse through mitral valve during diastole (Figure 3 It follows, if there are no constitutive signs and symptoms (as in our patient), differentiating between these 2 masses (tumor vs thrombus) can become difficult. 6,7 Left atrial myxofibrosarcoma may simulate LA myxoma in its clinical presentation, 1 as is true in our case and via TTE where the patient had presentation similar to an obstructive myxoma.CMR can add diagnostic information because of its capability of noninvasive tissue characterization if performed in addition to echocardiography. 8 However, in this case because of the large size of the mass, its origin from the LAA, areas of "necrosis," and most importantly the extreme rarity of cardiac primary myxofibrosarcoma, it was extremely difficult to diagnose with the available noninvasive imaging techniques.…”

“…It follows, if there are no constitutive signs and symptoms (as in our patient), differentiating between these 2 masses (tumor vs thrombus) can become difficult . Left atrial myxofibrosarcoma may simulate LA myxoma in its clinical presentation, as is true in our case and via TTE where the patient had presentation similar to an obstructive myxoma.CMR can add diagnostic information because of its capability of noninvasive tissue characterization if performed in addition to echocardiography .…”

Left atrial appendage mass: is it always a thrombus?

“…Their most common symptom is exertional dyspnea, but they can also cause fever, weight loss, syncope, sudden death, and hemoptysis [1, 2]. A cardiac myxoma is usually attached to the left atrial side of the interatrial septum near the region of the fossa ovalis [3]. However, in very rare cases, myxomas can originate from the LAA.…”

“…On the echocardiogram, myxomas are typically seen as attached to the endocardium with a pedicle [3]. If the location of the pedicle is not fully identified on echocardiography, it may be difficult to differentiate a left atrial myxoma from a thrombus [5].…”

An uncommon presentation of partially ligated left atrial appendage on transesophageal echocardiography

“…[3] Left atrial thrombus and LA myxoma are the common causes of a LAA echodensity. [4] In our patient, the incompletely ligated LAA masqueraded as Letter to Editor a thrombus. In the absence of TEE, the LAA may have been left partially patent that may serve as a potential site for thrombus formation.…”