Left Atrial Undifferentiated Pleomorphic Sarcoma Causing Mitral Valve Obstruction
A 61-year-old Latino woman with no past medical history presented to the emergency department with 2 weeks of gradual onset of dyspnea on exertion, cough, and palpitations. She denied any recent illnesses, fevers, or unintentional weight loss. She was not taking any medications or using tobacco, alcohol, or illicit drugs.
On physical examination, she had a temperature of 100.6°F, a heart rate of 122 bpm, respiratory rate of 25 breaths per minute, blood pressure of 155/92 mm Hg, and oxygen saturation of 92% on bilevel positive airway pressure. Her physical examination was notable for jugular venous distension, a loud S1 and normal S2, a grade 2/6 middiastolic murmur heard loudest at the apex, crackles throughout her posterior lung fields, and trace bilateral lower-extremity edema.
Her ECG showed sinus rhythm with no significant ST-T abnormalities (Figure 1). A portable chest radiograph showed mild enlargement of the cardiac silhouette, bilateral air space opacities, and small bilateral pleural effusions (Figure 2). Computed tomography of the chest with intravenous contrast was done to evaluate for pulmonary embolism; it revealed a mass with lobulated margins within the left atrium (Figure 3) protruding into the left ventricular cavity and infiltrating the left atrial wall.
An emergent transthoracic echocardiogram showed normal left and right ventricular systolic function. A large mass in the left atrium was seen prolapsing into the left ventricle during diastole, causing functional mitral stenosis, and was attached to the posterior wall of the left atrium. The patient was admitted for intravenous diuresis and was evaluated by the cardiothoracic surgery service for tumor excision.
A preoperative coronary angiogram demonstrated extensive tumor blush with filling from the left atrial recurrent branch from the circumflex artery and from the sinoatrial artery and posterior left ventricular branch of the right coronary artery feeding the suspected tumor (Figure 4 and Movies I and II in the online-only Data Supplement).
The intraoperative transesophageal echocardiogram confirmed the transthoracic echocardiographic findings of a large 5-cm soft tissue density in the left atrium with a mobile, pedunculated component prolapsing into the left ventricle during diastole (Figure 5 and Movie III in the online-only Data Supplement). The mass caused a functional mitral stenosis with a valve area calculated as 1.1 cm2 and a mean gradient of 7 mm Hg. The left atrium was accessed by first opening the right atrium and then the interatrial septum. The left atrial mass was adherent to the posterior wall of the left atrium and extended to the orifice of the left atrial appendage but spared the mitral leaflets (Figure 6). A pedunculated portion protruding through the mitral valve was excised (Figure 7); however, the rest of the mass could not be excised because it was infiltrating through the posterior wall to the visceral pericardium and into the atrioventricular groove (Figure 8). The pathological specimen later revealed a pleomorphic undifferentiated high-grade sarcoma (Figure 9).
The patient's postoperative course was complicated by several days of hypotension and accelerated junctional rhythm requiring inotropic support with dopamine, which gradually resolved with return of the patient's native sinus rhythm. The patient was discharged with recommendation for follow-up at the Oncology and Cardiology Clinic with serial transthoracic echocardiogram surveillance and for evaluation of chemotherapy/radiation therapy options. She is doing well 2 months after discharge and is receiving outpatient chemotherapy with doxorubicin and cyclophosphamide.
Primary cardiac tumors are rare, with an incidence of ≈0.0017% to 0.019%, with 25% of these tumors being malignant.1 The undifferentiated sarcomas are very rare, are known to primarily occupy the left atrium, and can be mistaken for a myxoma,1 causing pulmonary congestion. Sarcomas can also cause symptoms of dyspnea, syncope, chest pain, fever, malaise, and weight loss due to valvular inflow obstruction, arrhythmias, pericardial involvement and effusion, and tumor emboli. This case illustrates many of these features as a new presentation.
Survival depends on the extent of successful resection of sarcomas because of their high potential for recurrence and the presence of metastatic disease. Mean survival after excision has been documented to be ≈9 to 10 months; a significant predictor of long-term mortality is New York Heart Association Class III and IV symptoms.2 The benefit of adjuvant chemotherapy and radiotherapy is unknown given the limited data and the lack of randomized trials; complete surgical section has been the only factor that influences survival.1,3
The online-only Data Supplement is available with this article at http://circ.ahajournals.org/cgi/content/full/CIRCULATIONAHA.110.974345/DC1.
- © 2011 American Heart Association, Inc.