Primary Cardiac Angiosarcoma Presenting as a Rapidly Growing Right Atrial Mass

A right atrial mass is a rare finding that is often incidentally reported on echocardiogram or other imaging studies. It can be caused due to a thrombus, primary or metastatic cardiac tumor, vegetation of the tricuspid valve, or as a normal variant.¹ Primary tumors of the heart are extremely rare, with a reported incidence of about 0.02%.² Primary cardiac angiosarcomas are the most aggressive and invasive subtype of primary tumors.² They are often associated with cardiac tamponade and recurrent episodes of pericardial effusion.³ Complete surgical resection is the best treatment option.⁴ We present a case of a 44-year-old woman who presented with exertional dyspnea and was found to have a 7.0 cm x 3.5 cm right atrial mass on transthoracic echocardiogram that required surgical resection. Pathology of the mass showed a highly aggressive primary cardiac angiosarcoma that grew within 5 months. 

Case  

The patient is a 44-year-old woman with a history of diabetes mellitus type II, hypertension, and thyroid nodule with partial thyroidectomy 6 years ago, who presented to our institution in September of 2016 for dyspnea on exertion, generalized weakness, and intermittent chest discomfort for few days. She denied history of a hypercoagulable state or active malignancy. The patient was seen at our institution in April of 2016 for an evaluation of pericardial effusion and had a pericardial window. Transthoracic echocardiogram at this time showed small pericardial effusion, but there was no evidence of any atrial mass, tricuspid stenosis, or right ventricle compromise (Panel 1).  

On exam, she was hemodynamically stable with a heart rate of 85, blood pressure of 118/85, respiratory rate of 16, and arterial oxygen saturation (SaO₂) of 99% on room air. Her cardiopulmonary exam was within normal limits, with no jugular venous distention, no murmurs/rubs/gallops, and no wheezes, rales, or rhonchi. She only complained of mild right upper quadrant tenderness to palpation on abdominal exam. She had no peripheral edema. Chest x-ray showed cardiomegaly. Troponins were negative x3. An electrocardiogram (EKG) showed no ST segment changes. Transthoracic echocardiogram showed right atrial dilation with a large right atrial mass measuring 7.0 cm x 3.5 cm occupying the right atrial cavity and nearly occluding right atrial outflow across the tricuspid valve (Panel 2). A transesophageal echocardiogram done 5 days later confirmed these findings (Panel 3). There was subsequent superior and inferior vena cava dilatation. Right-to-left atrial septal displacement suggested elevated right-sided pressures. Ejection fraction was reported to be 60-65%. A computed tomography (CT) scan of the chest further revealed that the mass was extending into right ventricle and pericardium. There was evidence of bilateral pulmonary emboli. 

Cardiothoracic surgery was required due to large obstructing right atrial mass with subsequent tricuspid valve stenosis and right ventricle dysfunction. A right mini thoracotomy was performed with complete resection of the right atrial mass (gross image, Panel 4) and partial resection of right atrial wall. The mass was pulsating because of its vascularity and had a broad 3 x 3 cm stalk coming from the lateral wall of the right atrium. Right atrium and right ventricle function improved post resection. The mass was sent to pathology, which revealed a high grade angiosarcoma with spindle cells and associated necrosis. Immunohistochemistry revealed that the tumor is strongly positive for CD31, CD34, and SMA, while negative for melanoma markers.

Discussion

A primary cardiac angiosarcoma is a highly aggressive cardiac tumor with a fast growth rate and poor prognosis. In our patient, the tumor grew to the size of 7.0 cm x 3.5 cm in the span of merely 5 months. Because an angiosarcoma grows within the myocardial wall, diagnosing can be difficult through imaging.³ In addition, the symptoms of a right atrial mass tend to be non-specific and depend on the location of the mass, rather than its histological subtype, which makes it difficult to diagnose at an early stage.^3,5 However, early diagnosis is critical for a good prognosis. This is because of the tendency of an angiosarcoma to locally invade and distantly metastasize at a fast rate.⁵ Prompt surgical resection is necessary to prevent mortality.⁵

References 

1. Leitman M, Kuperstein R, Medalion B, Stamler A, Porat E, Rosenblatt S, et al. A highly unusual right atrial mass presented in two women. Eur J Echocardiogr. 2008 Nov; 9(6): 833-834. doi: 10.1093/ejechocard/jen173.
2. Park WK, Jung SH, Lim JY. Cardiac angiosarcoma on the right atrium: two cases. Korean J Thorac Cardiovasc Surg. 2012 Apr; 45(2): 120-123. doi: 10.5090/kjtcs.2012.45.2.120.
3. Enkhtaivan B, Govindu R. Rare primary cardiac angiosarcoma presenting as recurrent cardiac tamponade. CHEST Journal. 2016 Oct; 150(4_S): 273A-273A.
4. Chen SW, Chu PH, Shih LG, Lu MS, Shen WC, Huang YK. Right atrial angiosarcoma: rupture and tamponade. Tex Heart Inst J. 2012; 39(1): 153-155.
5. Shanmugam G. Primary cardiac sarcoma. Eur J Cardiothorac Surg. 2006 June; 29(6): 925-932.

^aRutgers Robert Wood Johnson Medical School, Piscataway, New Jersey

^bRobert Wood Johnson University Hospital, New Brunswick, New Jersey

Disclosure: The authors report no conflicts of interest regarding the content herein.

The authors can be contacted via Vatsal Bhatt, MSIII, at bhattvy@rwjms.rutgers.edu.