Left ventricular outflow tract obstruction due to a left ventricular myxoma that was misidentified as an accessory mitral valve tissue

Abstract

We report obstruction of the left ventricle outflow tract (LVOT) caused by cardiac myxoma that was misidentified as an accessory mitral valve tissue preoperatively. A 65-year-old woman presented with chest discomfort that persisted for 7 days. Transthoracic echocardiography (TTE) revealed a mobile, lowechogenic, balloon-shaped mass attached to the anterior mitral valve leaflet and papillary muscle, which was suspected to be an accessory mitral valve tissue. Because the mass caused LVOT obstruction and it could result in hemodynamic instability, emergency operation was performed. Intraoperative transesophageal echocardiography (TEE) was performed, and the mass had irregular margins and was pedunculated, with a stalk originating from the left ventricle (LV) wall and extending to the lateral chordae of the mitral valve. The surgeon excised the mass filled with the myxomatous mass, which was yellowish and gelatinous and had a stiff stalk, and histopathologic diagnosis confirmed a myxoma. Although mitral valve or LV myxomas are rare, TEE is a useful tool for distinguishing a myxoma from other intracardiac masses, such as vegetation or an accessory mitral valve tissue.

Left atrial myxoma with left ventricular myxoma diagnosed by ultrasound examination

“…Mitral valve prolapse and mild mitral regurgitation may be caused by the mass attached to the anterior lobe of the mitral valve. [ 16 ] The TEE features of left atrial myxoma present as a mass attached to the atrial septum. The tumor could protrude into the left ventricle through the mitral valve and block the mitral valve during diastole.…”

“…In mitral stenosis and atrial fibrillation, thrombus may appear in any part of the left atrium. Baek SH et al [ 16 ] misidentified the LV myxoma as an accessory mitral valve tissue by TTE, but on TEE the mass was accurately diagnosed as LV myxoma. Francois J et al [ 14 ] showed a LV myxoma attached to chordeae tendinea in an asymptomatic patient through TEE.…”

An Extremely Rare Cause of Mitral Regurgitation—Accessory Commissural Mitral Tissue with Anomalous Left Atrial Chordal Attachment

“…TEE may also help differentiate AMVT from other entities including myxomas, papillary fibroelastomas, and vegetations, which can have a similar echocardiographic appearance and produce similar LVOT mass effect on TTE images 9, 10. Baek et al.…”

“…Baek et al. 10 for example, reported a case of LVOT obstruction secondary to cardiac myxoma that was misdiagnosed as AMVT on preoperative TTE.…”

Left Ventricle Outflow Obstruction by Reverse-Oriented Tricuspid Semilunar Valve-Like Endocardial Duplicatures

“…In our case, semilunar valve-like structures were positioned on the muscular part of the outflow channel, which differed from the accessory mitral valve leaflet that outgoes from the membranous structure—the anterior mitral valve leaflet, and is connected to the anterolateral papillary muscle via a strand of chordal tissue [ 15 ]. Other pathologies that could produce left ventricular outflow obstruction account tumors, that is, myxoma [ 16 ] or a dynamic left ventricular outflow obstruction induced by other preexisting pathological conditions [ 17 , 18 ].…”