A 73-year-old non-obese man with a history of hypertension, coronary artery disease, and hyperlipidemia presented to our institution for off-pump coronary artery bypass grafting. Consent for publication of this case has been obtained from the patient. After induction of general anesthesia, a comprehensive transesophageal echocardiography (TEE) examination was performed. The midesophageal 4-chamber (ME 4C) view demonstrated an extrusion of the myocardial wall at the base of the anterior tricuspid valve (TV) annulus by 2-dimensional (2-D) (Video 1, see Supplemental Digital Content 1, http://links.lww.com/AA/A566) and 3-D (Fig. 1; Video 1, http://links.lww.com/AA/A566) imaging. The mobile, well-circumscribed, homogenous mass was not pedunculated, lacked cystic characteristics, and measured 1.8 × 2.2 cm. The modified bicaval view (Fig. 2; Video 2, see Supplemental Digital Content 2, http://links.lww.com/AA/A567) confirmed that the anterior leaflet was anchored to the mass. The mass was noted in close proximity to the right atrial appendage but did not involve the crista terminalis. The transgastric (TG) short-axis view (Video 3, see Supplemental Digital Content 3, http://links.lww.com/AA/A568) further established the relationship of the bright echogenic mass and the anterior leaflet of the TV. Three-dimensional TEE imaging in the ME 4C view provided a unique perspective of the valvular geometry that helped elucidate how the mass might affect TV structure and function. Three-dimensional imaging revealed normal TV leaflets and annulus with unhindered opening of the TV leaflets in diastole (Video 1, see Supplemental Digital Content 1, http://links.lww.com/AA/A566). Color-flow Doppler analysis of the TV demonstrated mild tricuspid regurgitation (Video 3, see Supplemental Digital Content 3, http://links.lww.com/AA/A568). Continuous-wave Doppler was not obtained, but tricuspid stenosis was excluded on the basis that there was no thickening or shortening of the valve leaflets, there was a low-velocity laminar flow, and there was a lack of turbulence or aliasing by color-flow Doppler across the TV. After discussion with the surgical team, the decision was made not to excise the incidentally identified lesion since it was presumed to be benign lipomatous hypertrophy of the TV annulus. The mass did not significantly affect TV structure or function, nor cause hemodynamic compromise. The patient did not have associated lipomatous hypertrophy of the interatrial septum. The off-pump coronary artery bypass grafting proceeded uneventfully, and the patient was discharged from the hospital on the fifth postoperative day in stable condition.
The echocardiographic differential diagnosis for cardiac valvular masses includes primary benign neoplasms, primary and secondary (metastatic) malignant neoplasms, thrombi and vegetations (Table 1).1–3 Isolated valvular lipomatous lesions (benign primary neoplasms) are very rare and tend to be an incidental finding on perioperative cardiac imaging or surgery.3,4
Five other cases of nonencapsulated lipomatous lesions solely involving the TV have been reported.1,3,4 These lesions predominantly affect the septal leaflet.1,3 However, lesions specifically affecting the TV annulus, as observed in this case, most commonly attach along the anterior aspect of the valve with the anterior leaflet having the appearance of being anchored to the base of the mass.4,6 Intraoperatively, lipomatous lesions can often be diagnosed based on clinical presentation and echocardiography (Table 1). A tissue biopsy is not necessary.
A systematic approach using 5 specific views is necessary to perform a thorough investigation by TEE of the TV, including its 3 leaflets (anterior, posterior, and septal).7 In the ME 4C view (0°–30°), the anterior leaflet (or posterior leaflet with additional probe retroflexion) can be visualized adjacent to the right atrial and right ventricular (RV) free wall, while the septal leaflet can be visualized adjacent to the ventricular septum. The ME RV inflow–outflow view (50°–70°) displays the posterior leaflet adjacent to the RV free wall and the septal or anterior leaflet adjacent to the aortic valve (depending on probe anteflexion or rightward turn). In the modified bicaval view (110°–120°), the posterior leaflet is viewed more posterior and on the left side of the imaging display near the coronary sinus, while the anterior leaflet is more anterior and toward the right side near the right atrial appendage. The TG midpapillary short-axis view (20°–50°) is the only view where all 3 leaflets can be imaged simultaneously. In this view, the septal leaflet is closest to the interventricular septum, the posterior leaflet is closest to the TEE probe, and anterior leaflet is on the left side of the image, near the RV free wall. Finally, in the TG RV inflow view (90°–120°), the anterior and posterior leaflets can both be imaged (posterior leaflet closest to the TEE probe inferiorly). Due to the difficulty in evaluating all 3 TV leaflets and their attachment to the annulus simultaneously in 2-D imaging, 3-D TEE of the TV allows for evaluation of the entire TV apparatus from multiple perspectives to help elucidate any pathophysiology.
The decision of whether or not to excise a seemingly benign cardiac lipomatous valve lesion to avoid life-threatening complications is challenging. Lipomatous valvular masses have the potential to affect the integrity of the valve, involve the adjacent atrial tissue, and/or the papillary muscles. Right-sided lipomatous lesions, large enough to cause circulatory obstruction and hemodynamic compromise, are likely to affect valvular function and cause right atrial cavity encroachment or narrowing of either cavoatrial junction as diagnosed with TEE.5 Any signs or symptoms of valvular obstruction, ventricular dysfunction, intractable arrhythmias, hemodynamic compromise, or malignancy should warrant further investigation and may necessitate surgical intervention.4,5 However, most reported cases of lipomatous TV lesions were asymptomatic, did not significantly affect valve function or structure, caused only mild tricuspid regurgitation, and were incidentally noted on TEE or autopsy.1,3,4,6 Asymptomatic patients with TV lipomatous lesions may be observed conservatively with interval follow-up and cardiac imaging. TEE is, therefore, an invaluable intraoperative tool to diagnose incidental valvular lesions and define the need for excision.
Clinician’s Key Teaching Points
By Martin M. Stechert, MD, Roman M. Sniecinski, MD, and Martin J. London, MD
- Lipomatous infiltration (otherwise known as hypertrophy) of the interatrial septum is a benign finding that is frequently noted during a routine transesophageal echocardiography examination. However, this same finding in a location other than the interatrial septum is rare and should be differentiated from other cardiac masses.
- Intracardiac masses include vegetations, thrombus, and both benign and malignant neoplasms. A systematic approach to their examination should include 2-dimensional ultrasound for assessing mobility, measuring size, determining relative echogenicity, and describing the mass’s relationship to surrounding structures. In addition, both spectral and color-flow Doppler should be used to assess any impact on cardiac valve function.
- In this case, a right atrial mass adjacent to the tricuspid valve annulus was noted incidentally. Echogenic appearance was most consistent with a benign, unencapsulated lipomatous cardiac valve lesion. Although the mass appeared anchored to the anterior leaflet of the tricuspid valve, this did not interfere with function of the tricuspid valve, and so the decision was made to leave it alone.
- Incidental masses are commonly encountered during a routine intraoperative transesophageal echocardiography examination. It is therefore important for the echocardiographer to be familiar with the general appearance of benign lesions and to be able to determine whether they have any functional impact.
Name: Christopher C. Rigsby, DO.
Contribution: This author helped analyze the data, write the manuscript, and perform literature search.
Attestation: Christopher C. Rigsby approved the final manuscript.
Name: Yasdet Maldonado, MD.
Contribution: This author helped analyze the data and write the manuscript.
Attestation: Yasdet Maldonado approved the final manuscript.
Name: Alexander R. Hellman, MD.
Contribution: This author helped edit/prepare TEE images and videos.
Attestation: Alexander R. Hellman approved the final manuscript.
Name: Richard A. Field, DO.
Contribution: This author helped write the manuscript and manage the patient and obtained a comprehensive TEE examination.
Attestation: Richard A. Field approved the final manuscript.
Name: Mark A. Taylor, MD.
Contribution: This author helped write the manuscript.
Attestation: Mark A. Taylor approved the final manuscript.
Name: Christopher A. Troianos, MD.
Contribution: This author helped edit the manuscript.
Attestation: Christopher A. Troianos approved the final manuscript.
This manuscript was handled by: Martin J. London, MD.
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