Cardiac Tumours

The heart may rarely be affected by primary or secondary tumours. Secondaries may occur by local extension or haematogenous spread. Most cardiac tumours arise from or occupy the myocardial or pericardial tissues. Myxomas account for around 50% of all cardiac tumours with the remainder made being a mixture of rare primary and secondary tumours.¹ They can present a significant diagnostic challenge causing symptoms and signs that mimic other cardiac diseases. Detection is now much easier with echocardiography and MRI scanning.

• They are quite rare. The prevalence from a post-mortem series is 0.0001–0.5% of the population.²
• Myxomas are responsible for about 50% of these tumours in those aged 30–60.²
• The commonest primary malignant tumours of the heart and pericardium are sarcomas.³
• The incidence is different in different age groups.
  The following tumours mainly affect children:
  • Rhabdomyoma
  • Fibroma
  • Teratoma
  • Hamartoma
  • Purkinje tumours
  Tumours mostly occurring in adults include:
  • Cardiac myxoma
  • Lipomatous septal hypertrophy
  • Paraganglioma
  • Sarcomas
  Some affect all age groups:
  • Papillary fibroelastoma
  • Haemangioma
  • Lipoma

• Myxomas:
  • Often asymptomatic and may be discovered accidentally.
  • They can cause constitutional symptoms such as fever, malaise, tachycardia and tachypnoea (release inflammatory mediators).
  • They may produce symptoms and signs of ischaemia or infarction in the peripheries due to embolisation of adherent thrombus.
  • Large myxomas may impair intracardiac blood flow causing dyspnoea, syncope or symptoms and signs of congestive cardiac failure.
• Rhabdomyomas:
  • Tend to be associated with atrioventricular valves and can arise and regress spontaneously.
  • They commonly present with atrial arrhythmias or heart block.
  • They are commonly associated (around 80% of cases) with tuberous sclerosis.
  • They usually remain small, but if large can cause symptoms due to intracardiac obstruction of blood flow.
• Fibromas, haemangiomas and lipomas:
  • Cause symptoms through their mass effect within the heart and usually give rise to symptoms of right or left ventricular outflow obstruction (such as dyspnoea, hepatic engorgement, peripheral oedema and episodes of syncope).
  • If these tumours occur on the interventricular septum they may cause arrhythmias.
• Papillary fibroelastomas:
  • Usually occur on the mitral (most commonly) or aortic valves.
  • They are usually asymptomatic and discovered during echocardiography.
  • Occasionally they may cause embolic phenomena.
• Lipomatous septal hypertrophy:
  • Causes arrhythmias, particularly atrial dysrhythmia and heart block.
• Hamartomas (Purkinje tumours):
  • Cause refractory ventricular tachycardias in infants.
• Teratomas and paragangliomas:
  • Often cause external compression of the heart. This leads to symptoms and signs of pericardial tamponade such as hypotension, fatiguability, dyspnoea, elevated JVP and Kussmaul's sign (JVP rising during inspiration).
  • They may also cause a superior vena cava syndrome.
  • Paragangliomas may manifest due to systemic symptoms caused by tumour products leading to hypertension, headache, flushing and palpitations.
• Secondary tumours of the heart:
  • Usually infiltrate the pericardium and cause symptoms and signs of pericardial effusion and tamponade.
• Phaeochromocytoma:
  • Synthesise catecholamines in about half of all cases.
  • Classical symptoms and signs of catecholamine excess include hypertension, dysrhythmias, anxiety, palpitations, flushing, headache and hyperhidrosis.
• Tumours of the sarcoma group:
  • Tend to present with non-specific symptoms such as dyspnoea, chest pain, episodic syncope and lassitude or fatiguability. The presence of chest pain strongly suggests malignancy.
  • Haemoptysis may be a presenting feature.
  • Tumour embolisation from the left side of the heart leads to stroke, fits, visceral or limb infarction and tumour metastasis at distant sites.
  • Signs associated with these tumours include diminution of the heart sounds, pericardial friction rub, pericardial effusion, crackles in the lung fields, refractory dysrhythmias, heart block and cardiac failure.
  • Extensively infiltrating tumours may cause superior vena cava syndrome and dysphonia due to recurrent laryngeal nerve palsy.

• Cardiac valvular disease
• Infective endocarditis
• Ischaemic heart disease causing angina or other abnormalities
• Restrictive cardiomyopathy
• Constrictive pericarditis
• Lung cancer
• Mesothelioma
• Mediastinitis, for example due to oesophageal rupture
• Other mediastinal tumours or disease processes
• Pericarditis
• Primary cardiac dysrhythmia

• ESR and other inflammatory markers may be elevated.
• CXR may show an abnormally large cardiac outline or evidence of atrial enlargement.
• ECG may show evidence of dysrhythmia, voltage reduction due to pericardial disease and non-specific ST segment and T-wave abnormalities.
• Pericardiocentesis may be used to obtain pericardial fluid for biochemical and cytological analysis.
• Echocardiography (preferably via transoesophageal route) is the gold standard for detecting and analysing the haemodynamic sequelae of intracardiac tumours or pericardial disease.
• MRI can detect intra-cardiac tumours.
• Cardiac catheterisation may be employed to analyse haemodynamic parameters.
• Endomyocardial biopsy may rarely be conducted. Most biopsy samples are obtained during surgical exploration and intervention.
• A specific test for paragangliomas is the metaiodobenzylguanidine (MIBG) scan. The radioactively-labelled guanidine analogue is taken up by neuroendocrine cells and demonstrates the tumour presence and position.

• The Carney complex is an autosomal dominant condition with variable penetrance that is thought to be the underlying cause of up to 10% of myxomas.⁴ Older names for the condition include LAMB syndrome (lentigines, atrial myxoma, mucocutaneous myxoma and blue naevi) or NAME syndrome (naevi, atrial myxoma, myxoid neurofibroma and ephilides). There are a group of abnormalities found in association with a tendency to atrial myxomas, such as cutaneous myxomas, spotty skin pigmentation, endocrinopathies and endocrine and other tumours.
• Tuberous sclerosis is strongly associated with rhabdomyomas in children. They may be diagnosed prenatally on ultrasound examination.⁵ They may be the only presenting feature of tuberous sclerosis in some children who do not have other typical features, or in whom signs of the disease are not detected until the cardiac tumour raises the suspicion.

• Medical therapies such as β-blockers (particularly for paragangliomas), other anti-hypertensives and anti-arrhythmics may be used as initial stabilising therapy.
• Most intra-cardiac tumours are excised surgically. This therapy is curative for benign tumours, although they may recur later in life.
• Malignant tumours such as sarcomas are rarely cured by resection, but cardiac function may be significantly improved, reducing symptoms. Adjuvant chemotherapy and radiotherapy have not demonstrated any significant benefits in terms of survival but may improve quality of life measures.³
• Secondary cardiac tumours usually carry a poor prognosis and respond poorly to surgical or other curative attempts.
• Pericardiotomy or pericardial fenestration may help relieve symptoms caused by pericardial disease.
• Cardiac transplantation has been used to treat malignant and some benign cardiac tumours. Long-term outcomes are unclear due to the small number of cases involved.⁶

• Left, right or combined ventricular failure
• Cardiac valvular dysfunction
• Heart block of varying degrees
• Other cardiac dysrhythmias
• Pericardial effusion and tamponade
• Embolic events including stroke
• Distant tumour metastasis
• Superior vena caval obstruction
• Systemic upset due to secretion of bioactive mediators by tumour
• Sudden death due to acute haemodynamic compromise in advanced cases
• Tumour recurrence after resection

Benign tumours usually carry a good prognosis with normal life expectancy post-resection. Patients who have had benign tumours resected are usually followed up with regular echocardiography and cardiological supervision. Malignant tumours such as sarcomas tend to do very poorly despite intervention, with median survival from diagnosis about 6 months.³ Occasional cases of survival due to complete resection do occur. Secondary malignancy affecting the heart has a grave outlook, although there is much that can be done to palliate the worst effects of the condition.

Patients with diseases known to be associated with cardiac tumours should be screened clinically and usually with echocardiography to detect the presence of intra-cardiac growths. Patients who have had benign tumours resected should usually be followed up with echocardiography and cardiological assessment to detect recurrence.