A large mass in the right ventricle: Tumor or thrombus?

A 69-year-old woman with hypertension, diabetes mellitus, and chronic kidney disease presented with a 1-month history of worsening episodic dyspnea, lower-extremity edema, and dizziness. Two months earlier, she had been diagnosed with poorly differentiated pelvic adnexal sarcoma associated with a mature teratoma of the left ovary, and she had undergone bilateral salpingo-oophorectomy, pelvic and para-aortic lymph node dissection, and omentectomy.

Examination revealed tachypnea (23 breaths per minute) and bilateral pitting pedal edema. The neck veins were distended. There was no hepatomegaly. Results of laboratory testing were unremarkable.

Chest radiography showed a homogeneous opacity in the lower lobe of the right lung with multiple nodules. Computed tomography (CT) without contrast confirmed the presence of innumerable scattered ground-glass pulmonary nodules, consistent with metastatic disease (Figure 1). Also evident was trace pericardial effusion. Contrast was not used because of her kidney disease.

Two-dimensional transthoracic echocardiography performed at the bedside to evaluate her tachypnea and pedal edema demonstrated an echogenic right ventricular mass protruding into a dilated right atrium, with near-complete obstruction of the right ventricle (Figures 2–4). (See video 1 and video 2.) The tricuspid valve was not visualized. The left ventricle was normal in size and function.

This mass was thought to be a metastasis from her ovarian cancer. She was a poor candidate for surgery or chemotherapy and, unfortunately, soon died of respiratory failure.

EVALUATING A CARDIAC MASS

Noninvasive evaluation of cardiac masses includes echocardiography, CT, and magnetic resonance imaging (MRI). Echocardiography can show the anatomic location, the extent, and the physiologic consequences of an intra­cardiac mass by dynamic assessment during the cardiac cycle. While cardiac masses are often initially detected with transthoracic echocardiography, transesophageal echocardiography shows them better, especially if the mass is located posteriorly.

Thrombus, tumor, or vegetation?

If an intracardiac mass is discovered, we need to determine what it is.

Thrombosis is more likely if contrast echocardiography shows the mass has no stalk (thrombi almost never have a stalk), the atrial chamber is enlarged, cardiac output is low, there is stasis, the mass is avascular, and it responds to thrombolytic therapy. A giant organized thrombus can clinically mimic a tumor if it is immobile, is located close to the wall, and responds poorly to thrombolysis. A wall-motion abnormality adjacent to the mass, global hypokinesis, or a concomitant autoimmune condition such as lupus erythematosus or antiphospholipid antibody syndrome may also favor thrombosis.

Tumors in the heart are uncommon. The prevalence of primary cardiac tumors has been reported as 0.01% to 0.1% in autopsy studies. Metastases to the pericardium, myocardium, coronary arteries, or great vessels have been found at autopsy in 0.7% to 3.5% of the general population and in 9.1% of patients with known malignancy.¹

Vegetations from infective endocarditis should also be considered early in the evaluation of an intracardiac mass. They can result from bacterial, fungal, or parasitic infection. Vegetations are generally irregular in appearance, mobile, and attached to a valve. Left-sided valves are generally involved, and a larger mass may indicate fungal origin. Abscess from tuberculosis may need to be considered in the appropriate setting. Whenever feasible, tissue diagnosis is desirable.

Occasionally, there may be an inflammatory component to masses detected in the setting of autoimmune disease.