Primary Cardiac Leiomyosarcoma
When Valvular Disease Becomes a Vascular Surgical Emergency
A 50-year-old previously healthy woman was referred to our department for suspected mitral valve endocarditis because of a 3-week history of fever, weight loss, and the echocardiographic discovery of a mitral valve mass. On admission, the patient was cachectic (body mass index of 18 kg/m2) and subfebrile (37.5°C) with dyspnea at rest, jugular vein distension, and tender liver enlargement. Her heart examination showed regular tachycardia (100 bpm), apical systolic murmur (3/6 degree), and diastolic rumble.
The ECG showed sinus tachycardia (105 bpm) and signs of left atrial abnormality (wide, notched P wave measuring 140 ms; Figure 1). Chest x-ray revealed a cardiothoracic index of 0.6, with left atrial enlargement and interstitial edema (Figure 2).
Echocardiography showed an enlarged left atrium and a partially mobile mass on the mitral valve involving mainly the anterior leaflet and the anterolateral commissure (Figure 3A and 3B and Movies I and II in the online-only Data Supplement). This caused severe obstruction of the left ventricular inflow tract, with a mean transmitral gradient of 12 mm Hg and a functional valve area of 1 cm2 (Figure 4). Moderate mitral regurgitation was also noted. Transesophageal echocardiography confirmed the presence of a 22×11-mm highly mobile mass on the mitral valve oscillating between the left atrium and the left ventricle during the cardiac cycle (Figure 3C and 3D and Movie III in the online-only Data Supplement). No other intracardiac masses were detected.
Shortly after admission, the patient presented a transient episode of left calf pain, paresthesia, and reduced power in the left lower limb that lasted for 30 minutes with complete recovery. Abdominal ultrasonography with color Doppler showed a filling defect at the level of aortic bifurcation and origin at the common iliac arteries (Figure 5). The episode was interpreted as a possible peripheral embolic event.
Coronary angiography showed normal coronary arteries, but injection into the abdominal aorta revealed a round filling defect at the level of the aortic bifurcation (Figure 6). Immediately afterward, echocardiography was repeated and showed the disappearance of the mobile part of the mass (Movie IV in the online-only Data Supplement), with a decrease in the transmitral mean gradient (Figure 7).
Emergency surgical removal of both the intracardiac and intraaortic portions of the tumor was performed simultaneously under cardiopulmonary bypass. The mitral valve was excised with the anterolateral papillary muscle, which appeared on inspection to be invaded by the tumor, and a Sorin Bicarbon bileaflet mechanical mitral valve prosthesis (Sorin Biomedica, Saluggia, Italy) was implanted.
Gross examination of the valve showed a 2-cm brown mass, confirming infiltration of the papillary muscle, and a similar macroscopic appearance of the arterial tumor emboli (Figure 8A). Histological examination of both the valvular mass and the intraaortic embolus showed that the tumor consisted of spindle cell proliferation, suggesting cardiac sarcoma (Figure 8B). Immunohistochemistry revealed nuclear polymorphism with atypical mitosis (with low mitotic index of 2 to 3 per 10 high-power fields) with positive staining for smooth muscle actin and vimentin (Figure 8C and 8D), confirming the diagnosis of leiomyosarcoma.
A complete imaging workup was performed for a primary cause of the tumor (which was negative) and for secondary spread, which did not find any metastasis. Chemotherapy with docetaxel and gemcitabine was started, and 6 months after the initial diagnosis, the patient remained well and asymptomatic. Follow-up echocardiography at 6 months showed no cardiac tumor recurrence and normal prosthetic function.
Differential diagnosis between infective endocarditis and cardiac tumor can be difficult if based on the clinical picture alone, but echocardiography can be helpful in differentiating a cardiac tumor from a vegetation. Primary cardiac leiomyosarcoma is a very rare tumor with a poor outcome.1 The most common site of origin for a primary cardiac sarcoma is the left atrium, whereas mitral valve origin is unusual (2 in a 15-case series).2 Complete resection of these tumors can rarely be achieved, but palliative surgery is usually undertaken because many patients present with mechanical obstruction. Adjunctive chemotherapy, radiation therapy, or both are sometimes used. However, the optimal protocol and treatment efficacy are unclear.3 The average survival without operation is 6 to 12 months; surgery extends survival to ≈24 months.4
We would like to thank Ileana Arsenescu, MD, and Marian Albu, MD, for their assistance with vascular ultrasonography and arteriography imaging.
The online-only Data Supplement is available with this article at http://circ.ahajournals.org/cgi/content/full/121/21/e415/DC1.