Right Atrial Angiosarcoma

Case from: Roshan Weerackody, Ceri Davies, Mark Westwood

Institute: London Chest Hospital, London, United Kingdom, E2 9JX

Clinical history: 47 year old asian male who was previously well was referred to the Cardiology Out-patient clinic with chest pain, dypnoea and episodes of nausea and vomiting. He also reported 2 week history of night sweats, arthralgia and possible weight loss. He denied foreign travel. He was non smoker. He was apyrexial and physical examination revealed normal findings. ECG showed non specific T wave changes in the inferior and lateral leads (Fig 1). CMR study was performed to further clarify the diagnosis and plan treatment

Figure 1: ECG with nonspecific T wave changes

Transthoracic echocardiogram (TTE) showed a large right atrial mass associated with the right atrial free wall, small pericardial effusion, normal valves and preserved systolic function (Movies 1-4). The differential diagnosis included atrial thrombus, myxoma or primary or secondary cardiac tumour.

Movie 1: TTE (PLAX) with pericardial effusion & Movie 2: TTE (SAX) with pericardial effusion

Movie 3: TTE (SAX) with right atrial mass & Movie 4: TTE (Apical) with right atrial mass

CMR Findings: There were small bilateral pleural effusions and a small pericardial effusion seen. No enlarged lymph nodes were present in the mediastinum. The ventricles were not dilated and bi-ventricular function was preserved and septal motion was discordant (Movie 5). The right atrium was enlarged. There was a large mass attached to free wall and roof of the right atrium (72mm x 44mm). No obvious compression of the SVC or IVC was seen secondary to the mass (Fig 4 and 5). The pericardium was diffusely thickened and especially around the anterolateral wall of the LV (pericardial thickness around RV: 7mm; and anterolateral LV wall: 14mm).

Figure 2: Axial SSFP & Figure 3: Axial black-blood

T2-STIR imaging showed areas of increased signal intensity within the RA mass suggesting oedema (Fig 4). There was no fatty infiltration of the mass (Fig 5).

Figure 4: T2-STIR & Figure 5: Fat-sat black blood

Rest perfusion showed a large avascular area that would be consistent with areas of necrosis (Movie 6).

Late gadolinium imaging showed no enhancement of the LV or RV myocardium but diffuse uptake within the pericardium (Fig 6). The lack of early gadolinium enhancement also suggested a large avascular area (Fig 7). Late gadolinium enhancement within the RA mass corresponded to areas of necrosis (Fig 8).

Figure 7: Early enhancement & Figure 8: Late enhancement

Follow up: The patient underwent attempted excision of the mass. However, at surgical exploration through median sternotomy, the mass was clearly too extensive for surgical excision. There were multiple masses present within the pericardium with extensive adhesions. The major mass was occupying the right atrium and felt solid. The SVC felt hard on palpation, however, there was no direct obstruction of SVC or IVC. There was a further separate mass overlying the aorta and pulmonary artery anteriorly. Multiple biopsies were taken for further examination.

The histology of the specimens showed fibroconnective tissue invaded by a malignant tumour. The tumour was composed of small dark epithelioid cells arranged in solid sheets and cords with limited eosinophilic cytoplasm and focal vasoformative arrangement. Frequent mitotic figures were present. The stroma was fibrotic and showed chronic inflammation and haemosiderophages. The microscopic and immunohistochemical profile were consistent with an angiosarcoma.

Perspective: Angiosarcomas are the most common primary malignant neoplasm of the heart. The incidence peaks in the third to fifth decade and are more common in males. Ninety percent of the angiosarcomas are located in the right atrium. The most common site being the free wall and the septum being spared in most cases.

A variety of imaging modalities are available in the work up of a patient with a cardiac mass. Cardiac MRI enables the most comprehensive imaging assessment of cardiac masses. In contrast to other modalities, MRI provides improved soft tissue contrast, tissue characterisation as well as assessment of mediastinal and lung involvement by the tumour. Additional imaging with gadolinium contrast allows further characterisation of the tissue, the extent of vascular supply and further improves the differentiation from surrounding tissue.

The treatment of angiosarcomas are dictated by the local extent of the tumour and metastatic spread. Surgical resection or debulking of the tumour is indicated where possible. Additional treatment with chemotherapy, irradiation and cardiac transplantation have been reported with no significant impact on survival.

References:

Burke A, Jeudy J, Virmani R. Cardiac tumours: an update. Heart 2008 94: 117-123.
Randhawa K, Ganeshan A, Hoey E. Magnetic resonance imaging of cardiac tumours: Part 2, Malignant tumours and tumour like conditions. Curr Probl Diagn Radiol 2011 July/August: 169-179.

COTW handling editor: Kevin Steel

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