Cardiac Metastases with echocardiography

Case Study: Cardiac Metastases – An unusual cause of left atrial mass

A 33 year old gentleman was referred with increasing neck swelling in the cervical region. Biopsy of the swelling confirmed metastatic malignant melanoma. A staging CT of the chest revealed a 4 X 4cm filling defect within the left atrium. Echocardiogram performed showed abnormal left ventricular function. A large homogenous irregular sessile mass measuring 5.6 X 3 cm was seen attached to the basal free wall of the left atrium. It was not attached to the interatrial septum. It appeared to originate from the right pulmonary vein. The left atrium was mildly dilated. There is no stalk attached to the mass. The tip of the mass prolapses through the mitral valve during diastole. No spontaneous echo contrast could be seen in the left atrium or appendage.

We discuss the aetiology, diagnosis and management of cardiac metastases.

Transesophageal Echocardiogram

Transesophageal Echocardiogram

Transthoracic Echocardiogram

Transthoracic Echocardiogram

Discussion

The differential diagnosis of left atrial masses includes primary cardiac tumours, cardiac metastases, atrial myxoma and thrombus within the left atrium. Cardiac metastasis is uncommon and it is discovered in autopsies in 11.8% of all patients with malignancies1.  It usually occurs late in the course of a malignant disease and generally has a poor prognosis. Sites of origin2 include lung, non-solid primary malignancies including melanoma, sarcoma and lymphoma, breast and oesophagus. It has been reported that up to 64% of patients with melanoma have cardiac metastases2. There have been case reports of cardiac metastasis from cancer of the cervix, kidney and thyroid.

Patients with cardiac metastases may be asymptomatic as in our case. Some patients may present with cardiac arrhythmias, impaired cardiac function or pericardial effusion. Death attributed to cardiac invasion includes cardiac tamponade, congestive cardiac failure, coronary artery invasion and sino-atrial node invasion leading to fatal arrythmias.

Routes of invasion3 includes retrograde lymphatic extension, haematogenous spread, direct contiguous spread and transvenous extension.

Diagnosis of cardiac metastases can be made by echocardiogram (transthoracic and transoesophageal). CT and MRI scans can delineate the mass within the heart. The new technique of PET CT imaging enables us to identify the lesion as well as measures its metabolic activity using radio labelled glucose analogue 18-fluorodeoxyglucose (FDG).

In this case, our suspicion of cardiac metastasis was confirmed by PET CT imaging.

Though myxoma can not be completely excluded with out a histological diagnosis, it is very unlikely in our case, given the appearance and atypical location. We excluded the possibility of a thrombus as there were no spontaneous echo contrast and the mass was not arising from the pulmonary vein or atrial appendages.

Although less used, definitive diagnosis can be made by obtaining histo-cytology samples from the mass itself or the pericardial fluid in the presence of a pericardial effusion.

Management of cardiac metastases is usually palliative due to the advanced course of the malignant disease. There have been reports of surgical excision of the metastasis to improve quality of life and symptoms4 but this is mainly limited to patients with good karnofsky performance status, minimal extracardiac involvement, indolent course of disease and main symptoms stemming from cardiac involvement.

References

  1. Abraham KP, Reddy V, Gattuso P. Neoplasms metastatic to the heart: review of 3314 consecutive autopsies. Am J Cardiovasc Pathol 1990; 3: 195-8.
  2. Klatt EC, Heitz DR. Cardiac metastases. Cancer 1990; 65:1456-9.
  3. Schoen FJ, Berger BM, Guerina NG. Cardiac effects of noncardiac neoplasms. Cardiol Clin 1984; 2:657-70.
  4. Messner et al. Surgical Management of metastatic melanoma to ventricle. Tex Heart Inst J. 2003; 30(3):218-20.

 

Author:

Dr Prashanth Raju & Dr Gershin Davis
Cardiologists
University Hospital Aintree
UK

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