Cardiac Tumors - A Brief Introduction

Most cardiac tumors are secondary deposits. Cardiac metastasis occurs most commonly with lung and breast carcinomas. The most commonprimary cardiac tumor is a myxoma; 75% of myxomas occur in the left atrium, the remainder in the right atrium and ventricle. Myxomas usually arise from the endocardium at the border of the fossa ovalis as a pedunculated mass. This may prolapse through the mitral valve (MV) mimicking mitral stenosis.

Epidemiology:
The prevalence of myxoma is estimated at 2 per 100,000, most commonly in those aged 30–60 years. The female to male ratio is 2:1.

Clinical presentation:
Myxomas are discovered when individuals present withconstitutional upset or the effects of MV obstruction, or the tumour is an incidental finding. Symptoms include

• fever,
• malaise,
• exertional
• dyspnoea and
• weight loss.
• Transient
• pulmonary oedema,
• paroxysmal
• nocturnal dyspnoea,
• haemoptysis,
• dizziness and syncope may occur.
• The first presentation may be due to an embolic phenomenon.

- Malignant tumors usually present acutely with haemorrhagic pericardial effusions or heart block.
- Renal cell cancer invading the IVC may present with signs of right heart failure and a renal mass.
- Carcinoid metastasis to the tricuspid valve may present with facial flushing and bronchospasm.

Physical signs : Fever, finger clubbing and anemia of chronic disease reflect the chronic nature of myxomas. A tumour ‘plop’ may be heard, or auscultatory findings of mitral stenosis with or without regurgitation may be present. The murmur varies with posture, unlike in cases of valvular disease.

Investigations:
1.Blood tests: In myxomas these typically show the anemia of chronic disease, raised inflammatory markers (erythrocyte sedimentation rate and C-reactive protein) and gamma-globulins.

2. Chest radiograph: The tumor may distort the cardiac silhouette. Sudden cardiac or pericardial enlargement, mediastinal lymphadenopathy or an irregular/ indistinct cardiac border may be seen. Intracardiac calcification may occur in myxomas.

3. Echocardiography: This is usually visible on transthoracicecho, but transoesophageal echocardiography may be required in some cases.

Differential diagnosis: Consider endocarditis and MV disease.

Treatment:

• Urgent surgical resection of myxomas is required.
• Avoid the risks of embolisation.
• Most malignant tumours are treated palliatively, although renal cell tumors invading the IVC may be excised.
• Palliative chemotherapy may be appropriate for certain tumor types.

Complications: Myxomas may embolise or cause pulmonary oedema due to MV obstruction. Malignant disease may cause tamponade, heart block, arrhythmias and heart failure. Recurrent pericardial effusions are treated with a pericardial window.

Prognosis: Once removed, the prognosis for patients with myxoma is a normal lifespan.

Disease associations:
Myxomas can be familial (Carney’s syndrome or ‘syndrome myxoma’), with autosomal dominant transmission in 10% of cases. This is associated with endocrine hyperactivity, lentigines and myxomas elsewhere in the body. Multiple tumours occur in approximately 50% of familial cases, and are more common in the ventricle. The mean age of presentation of familial cases is 25 years, and for sporadic cases 56 years.