Cardiac masses remain a diagnostic challenge. Multimodality imaging, including transesophageal echocardiography (TEE), cardiac magnetic resonance (CMR), and cardiac computed tomography (CCT), is of pivotal importance in the diagnostic work-up to guide their proper treatment [1, 2]. We here present a case of recurrent biatrial cardiac masses in a patient with prothrombotic diathesis due to protein C deficiency.
An 85-year-old man with a history of coronary artery disease, aortic stenosis, and protein C deficiency underwent a TEE to confirm the presence of a left atrial mass that was suspected on a transthoracic echocardiogram. He had no previous history of atrial fibrillation. The TEE showed a large mass in the left atrium (LA) (Figure 1A; Supplementary material, Video S1), which appeared ovoid-shaped, mobile, with a thin stalk attached to the LA septum, of homogeneous echogenicity and regular borders. A CMR confirmed its morphological features (26 × 16 mm) and documented also a smaller mass (19 mm) attached to the right atrium (RA) base next to the RA appendage (Supplementary material, Video S2). At CMR, both masses showed an iso-intense signal at steady-state free procession cine sequences (Supplementary material, Videos S2–S4) and no contrast medium uptake at either first-pass perfusion (Figure 1B) or late gadolinium enhancement sequences. According to the diagnostic echocardiographic mass score, these two masses were likely to be benign [3]. In light of these imaging findings, and given the patient’s clinical characteristics, the masses were thought to be thrombi. After one year of anticoagulant therapy, a follow-up CMR showed a significant reduction in the dimension of the LA mass (8 mm) and complete disappearance of the RA mass. Unfortunately, autonomous early discontinuation of anticoagulant therapy contributed to thrombotic recurrence. After two years, a new and larger LA mass was shown (53 × 27 mm) via TEE (Figure 1C–D), CMR (Figure 1E), and cardiac computed tomography (Figure 1F). In addition, on this occasion, a smaller mass (11 mm) with no LGE was visualized in the RA at CMR (Figure 1E), but missed during TEE evaluation.
The patient ultimately underwent transcatheter aortic valve replacement for worsening aortic stenosis, followed by open surgical excision of both masses one week later.
This choice of staged treatment was based on the high surgical risk of a combined surgery involving simultaneously the aortic valve and the masses. Histological examination confirmed their thrombotic nature and excluded malignancy. Lifelong anticoagulation was prescribed. Follow-up has been uneventful two years after the surgical excision.
In conclusion, it is of utmost importance to correctly determine the nature of atrial masses in order to provide proper treatment. The main differential diagnoses include vegetations, tumors and thrombi [4]. Multimodality imaging is essential for their proper characterization, especially in uncommon cases of biatrial recurrent masses that can mimic metastases [5].
In the presented case, the use of CMR as a complement to echocardiography revealed, on the one hand, the simultaneous presence of a mass also in the RA and, on the other hand, confirmed their thrombotic nature. CMR was thus able to guide treatment even before diagnostic biopsy.
Supplementary material
Supplementary material is available at https://journals.viamedica.pl/polish_heart_journal.
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