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.
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.
Myxomas are discovered when individuals present withconstitutional upset or the effects of MV obstruction, or the tumour is an incidental finding. Symptoms include
- weight loss.
- 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.
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.
- 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.
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.