Cardiac Masses: The Role of Cardiovascular Imaging in the Differential Diagnosis

Abstract

Cardiac masses are space occupying lesions within the cardiac cavities or adjacent to the pericardium. They include frequently diagnosed clinical entities such as clots and vegetations, common benign tumors such as myxomas and papillary fibroelastomas and uncommon benign or malignant primary or metastatic tumors. Given their diversity, there are no guidelines or consensus statements regarding the best diagnostic or therapeutic approach. In the past, diagnosis used to be made by the histological specimens after surgery or during the post-mortem examination. Nevertheless, evolution and increased availability of cardiovascular imaging modalities has enabled better characterization of the masses and the surrounding tissue. Transthoracic echocardiography using contrast agents can evaluate the location, the morphology and the perfusion of the mass as well as its hemodynamic effect. Transesophageal echocardiography has increased spatial and temporal resolution; hence it is superior in depicting small highly mobile masses. Cardiac magnetic resonance and cardiac computed tomography are complementary providing tissue characterization. The scope of this review is to present the role of cardiovascular imaging in the differential diagnosis of cardiac masses and to propose a step-wise diagnostic algorithm, taking into account the epidemiology and clinical presentation of the cardiac masses, as well as the availability and the incremental value of each imaging modality.

Keywords: cardiac computed tomography; cardiac magnetic resonance; cardiac malignancies; cardiac tumors; contrast agents; echocardiography; transesophageal echocardiography.

Figure 1

Transesophageal echocardiography depicting the left atrial appendage using 2D and 3D approach ((A,B), respectively). A huge thrombus (arrows) is demonstrated in the upper part of the “coumadin ridge” is an elderly woman with severe mitral stenosis. Clot in the RA (red arrows). Cine and EGE imaging ((C,D) respectively).

Figure 2

Patient presenting with anterior myocardial infarction the second day after primary percutaneous transluminar coronary angioplasty (PTCA). Apical 4-chamber view. (A) A lesion is depicted on cardiac apex (yellow arrows), mobile, without vasculature, findings compatible with clot. (B,C) Large laminar LV thrombus adjacent to an area of apical myocardial infarction. Two chambers EGE (image (B)) and LGE (image (C)) respectively.

Figure 3

(A) A 65-year-old patient with fever and dyspnea for 15 days. Transthoracic echo (modified short axis view) demonstrated an amorphous mass (arrow) infiltrating the tricuspid annulus, right ventricular free wall and pericardium, causing a moderate in size pericardial effusion. (B) The pericardial fluid led to tamponade (B). Biopsy revealed a lymphoma.

Figure 4

(A,B) Spherical lesion 1.8 × 1.8 cm attached through a wide base close to fossa ovalis was depicted at TTE (A) (yellow arrow) and subsequently TEE (B) (blue arrows—3D zoom). The location of the tumor in the left atrium as well as its morphological characteristics are compatible with a myxoma. (C) 3D TEE showing a polypoid (yellow arrow), with a smooth or mildly lobar surface located at the entrance of the inferior vena cava. Echocardiographic findings are consistent with a myxoma in a rare position. (D) 3D TEE depicting a large mass with spot calcific areas located at the fossa ovalis with a wide base, findings consistent with a left atrium myxoma. Please note the areas with higher echogenicity within the mass (yellow arrows).

Figure 5

Incidental finding on TTE in an asymptomatic patient followed by TEE. The transesophageal image revealed a papillary fibroelastoma attached to the left cusp of the aortic valve (red arrows) 3D TEE with cropping in long axis (A,B), and short axis view ((C,D) during systole and diastole, respectively). Please note that the pedunculated lesion is attached on the tip of the aortic surface of the aortic valve, is not protruding in the LVOT during systole and doesn’t lead to valve destruction or insufficiency.

Figure 6

Long (A) and modified short axis (B) view of transthoracic echocardiography in a young female patient with metastatic carcinoma. Note the presence of pericardial effusion and the increased echogenicity and inhomogeneity of the basal posterior myocardial wall finding consistent with malignancy (red arrows). (C–F) Patient presenting with dyspnea on exertion and right heart failure symptoms during last months. A large mass (5.2 × 4.8 cm) is depicted inside the right atrium (C), originating from inferior vena cava (D). Utilizing echo contrast agents, the increased vasculature of the mass is revealed, a finding supportive of malignancy (E,F).

Figure 7

A 35-year-old patient with a round lesion located at the middle of intraventricular septum, known from 5 years ago, stable in size during follow-up (A,B). Using contrast agents, the mass is highly echogenic indicating increased vasculature with a surrounding halo (C,D). It is most likely an intramural hemangioma.

Figure 8

(A) 3D-TEE in a patient evaluated for a possible endocarditis. A large multilobular amorphous mass (vegetation) is found attached on the right commissure (3rd hour) of the anterior and posterior leaflet (AV: Aortic valve, LAA: Left atrial appendage). (B,C) A huge abscess infiltrating the aortic root and the aortomitral curtain in a young febrile patient with prosthetic aortic valve. (D) Transesophageal echocardiography-4 Chamber view. Increased thickness and echogenicity of both the tips of the leaflets in a patient with lupus erythromatosus endocarditis.

Figure 9

(A) Short-axis of late-gadolinium enhancement image demonstrating the echinococcus cyst attached to inferolateral wall, highly hypointense with hyperintense border (blue arrow). (B) CT demonstrated a calcified cyst (white arrow) proved to be a cardiac echinococcus cyst.

Figure 10

(A) Subxiphoid view with contrast agent. Round mass with mural thrombus and blood flow at the level of tricuspid annulus findings consistent with right coronary artery (RCA) aneurysm. (B) Coronary angiography confirmed the diagnosis.

Figure 11

Four chamber view using SSFP sequence of a 70-year-old man showing lipomatous hypertrophy of the atrial septum (arrow).

Figure 12

Step-by-step diagnostic algorithm for cardiac masses using cardiovascular imaging. Patient’s history, clinical data and ECG should be acquired and evaluated before extensive imaging work-up. With data extracted by the clinical evaluation and the TTE, a physician may initiate differential diagnosis and plan further work-up approach. When the mass is proved to be a thrombus (consider using ultrasound enhancing agents) no further work-up is needed. When thrombus is found on a prosthetic valve, TEE and/or CT can also be used. The next step is TEE especially for atrial masses. When the mass is vegetation or abscess then usually no-further work up is needed (consider PET scan as next best step when diagnosis is still under question). For other masses CMR is the next best step and guides further work-up which could include CT, or ¹⁸F FDG * For ventricular masses which are not adjacent to the cardiac valves and are not highly mobile, CMR can be alternatively used after the transthoracic echocardiogram without the need of TEE.