Cardiac Masses, Tumors & Thrombi

RDCS Adult Echocardiography AE

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1 Introduction & Exam Overview

The RDCS AE Exam, SPI Requirement & Logistics Content Outline, Domain Weights & How to Study

2 Cardiac Anatomy

Chambers, Walls, Myocardial Layers & the 17-Segment Model Cardiac Valves & Subvalvular Apparatus Great Vessels, Pericardium, Coronary & Venous Anatomy

3 Cardiac Physiology & Hemodynamics

Cardiac Cycle, Phases & Pressure-Volume Relationships Normal Systolic & Diastolic Function Hemodynamic Principles & Response to Stress

4 Echo Modalities, Instrumentation & Contrast

2D (B-Mode) and M-Mode Imaging Spectral, Color, and Tissue Doppler Modalities Image Optimization, Artifacts, and Contrast Echocardiography

5 Standard Views, Windows & Protocol

Parasternal Long- & Short-Axis Views Apical Views Subcostal & Suprasternal-Notch Views Exam Protocol, Patient Positioning & Provocative Maneuvers

6 Quantification & Doppler Hemodynamic Calculations

Chamber Quantification: LV, LA, RA, and RV Size, Mass, and Volumes Systolic Function: Ejection Fraction Methods, Fractional Shortening & Strain Diastolic Function Grading (ASE/EACVI 2016) Core Doppler Math: Modified Bernoulli, VTI, Stroke Volume & the Continuity Equation Advanced Hemodynamics: PISA/EROA, Pressure Half-Time, dP/dt, Qp/Qs & RVSP

7 Aortic & Mitral Valve Disease

Aortic Stenosis Aortic Regurgitation Mitral Stenosis Mitral Regurgitation

8 Right-Sided, Prosthetic & Infective Valve Disease

Tricuspid & Pulmonic Valve Disease and Pulmonary Hypertension Assessment Infective Endocarditis and Vegetations Prosthetic Valves and Postoperative Evaluation

9 Ischemic Disease & Cardiomyopathies

Coronary Anatomy, Ischemic Heart Disease & Wall-Motion Abnormalities Stress Echocardiography & Myocardial Viability Mechanical Complications of Myocardial Infarction Dilated & Restrictive Cardiomyopathy Hypertrophic Cardiomyopathy, SAM & LVOT Obstruction

10 Pericardial Disease, Masses & Aorta

Pericardial Effusion & Cardiac Tamponade Constrictive Pericarditis vs. Restrictive Physiology Cardiac Masses, Tumors & Thrombi Aortic Disease: Aneurysm, Dissection & Atheroma

11 Congenital Heart Disease & Shunts

Septal Defects & Shunt Quantification Common Adult Congenital Lesions

12 Clinical Care & Safety

Patient Care, Clinical-Data Integration & Exam Protocols Bioeffects, ALARA, Infection Control & Ergonomics

Cardiac Masses, Tumors & Thrombi

Key Takeaways Explain This Topic AI

Myxoma is the most common primary cardiac tumor in adults; roughly 75-80% arise in the left atrium and attach by a stalk to the fossa ovalis.

Papillary fibroelastoma is the most common tumor arising from a cardiac valve, typically appearing as a small, mobile, frond-like mass on the valve surface.

Metastatic tumors are far more common than primary cardiac tumors and most often involve the pericardium rather than the myocardium.

Left atrial appendage thrombus is best evaluated by transesophageal echocardiography because the appendage is poorly visualized transthoracically.

Chiari network, lipomatous hypertrophy of the interatrial septum, and Lambl's excrescences are normal anatomic variants that must not be mistaken for pathologic masses.

Last updated: July 2026

Overview of Cardiac Masses

Most masses encountered on echocardiography are not true neoplasms. Thrombi, vegetations (covered with infective endocarditis in Chapter 8), and normal anatomic variants are all far more common than primary cardiac tumors. When a mass is identified, systematic characterization of location, attachment (broad-based versus stalk/pedunculated), mobility, echogenicity/texture, and border definition — supplemented by contrast enhancement, multiplane TEE, or cardiac MRI/CT when needed — guides the differential diagnosis and downstream management.

Primary Cardiac Tumors

Myxoma is the most common primary cardiac tumor in adults, accounting for roughly half of all primary cardiac tumors. Approximately 75-80% arise in the left atrium, classically attached by a stalk to the fossa ovalis on the interatrial septum. Myxomas are typically mobile, heterogeneous in echogenicity (may contain calcification or areas of hemorrhage), and can prolapse across the mitral valve in diastole, producing an obstructive, mitral-stenosis-like physiology or exertional syncope; they also carry a meaningful embolic risk because fragments can break off and travel systemically.

Papillary fibroelastoma is the most common tumor arising from a cardiac valve, as opposed to myxoma, which is the most common cardiac tumor overall. It typically presents as a small, mobile mass with a characteristic frond-like, "shimmering" appearance, attached by a short stalk to a valve surface — most often the aortic or mitral valve, usually on the downstream (low-pressure) side of the valve. Despite its small size, it carries significant embolic risk, including stroke or, if aortic-valve-based, coronary embolism.

Cardiac sarcoma , most commonly angiosarcoma, is the most common malignant primary cardiac tumor in adults. It frequently arises in the right atrium, grows rapidly with infiltrative extension into surrounding structures, and carries a poor prognosis. Rhabdomyoma and fibroma are the most common primary cardiac tumors in children but are not typical adult-exam content.

Risk Stratification and Multimodality Follow-Up

Embolic risk for both myxoma and papillary fibroelastoma correlates with mobility and size: highly mobile masses, or fibroelastomas exceeding roughly 1 cm, are more likely to embolize and more often prompt surgical excision even when the patient is asymptomatic. Most sporadic myxomas are solitary, but a minority are multiple, recurrent, or familial — seen in Carney complex , an autosomal dominant syndrome that also features skin pigmentation abnormalities and endocrine tumors — and these patients warrant closer surveillance and consideration of family screening.

Because 2D and Doppler findings alone cannot always distinguish tumor type or reliably exclude malignancy, cardiac MRI (tissue characterization, contrast enhancement pattern) and, when embolic or biopsy questions remain, cardiac CT or surgical pathology are frequently used to complete the work-up. TEE also outperforms TTE for detecting small, mobile masses on valve surfaces, given its higher spatial resolution and closer proximity to the heart.

Metastatic (Secondary) Tumors

Metastatic tumors are dramatically more common than primary cardiac tumors — by some estimates 20- to 40-fold more common — and most frequently involve the pericardium rather than the myocardium, often presenting first as a pericardial effusion. Common primaries include lung and breast carcinoma, melanoma, and lymphoma; renal cell carcinoma is notable for direct venous extension through the inferior vena cava into the right atrium, a pattern the sonographer should specifically look for when a renal mass history is present.

Cardiac Thrombi

Left atrial appendage (LAA) thrombus develops most often in the setting of atrial fibrillation or mitral stenosis, where left atrial enlargement and reduced appendage emptying velocities promote blood stasis. Because the trabeculated appendage is poorly visualized transthoracically, TEE is required for reliable exclusion, and thrombus must be carefully distinguished from the normal pectinate muscles that line the appendage wall.

LV apical thrombus forms over regions of apical akinesis or dyskinesis — classically after an anterior myocardial infarction with apical aneurysm formation, or in non-ischemic cardiomyopathy with severely reduced ejection fraction. It typically has a layered, laminated appearance. Because the apex is a common site of near-field echo dropout on transthoracic imaging, contrast (LV opacification) should be used whenever apical thrombus is suspected but not clearly seen on unenhanced images.

Normal Anatomic Variants (Mass Mimics)

Structure Location Key Features Significance

Chiari network RA, near IVC/eustachian valve Filamentous, highly mobile Normal remnant of the right sinus venosus valve; no clinical significance

Lipomatous hypertrophy of the interatrial septum Interatrial septum, sparing the fossa ovalis Classic "dumbbell"/hourglass shape Benign fat deposition, not a true tumor

Lambl's excrescences Valve closure lines (aortic, mitral) Thin, filiform, mobile strands Degenerative, usually incidental, rarely an embolic source

Moderator band RV apical trabeculation Linear echodensity crossing the RV cavity Normal structure, not a mass

Recognizing these variants prevents unnecessary work-up, anticoagulation, or biopsy referral for a structure that requires no intervention — an important distinction from a genuine mass with real embolic or obstructive potential.

A useful practical rule when a mass is first seen: correlate location and clinical context before reaching for an exotic diagnosis. A mobile RA structure near the IVC/eustachian valve in an otherwise asymptomatic patient is almost always a Chiari network; a septal structure that spares the fossa ovalis and has a soft, homogeneous fat-like texture is almost always lipomatous hypertrophy; and thin filiform strands along a valve closure line in an older adult are almost always Lambl's excrescences. Reserving concern for masses that are large, broad-based, invasive into adjacent structures, or associated with pericardial effusion and systemic symptoms keeps the differential appropriately weighted toward the common, benign explanations.