Cardiac Tumours

Epidemiology

• Primary cardiac tumours are extremely rare
  • Metastatic tumours are 30-40 times more prevalent
  • Of all the primary tumours, myxoma is the most common, accounting for up to half of all primary benign tumours in adults
    • In children, rhabdomyomas are more common

Types

• Benign Primary tumours
  • Myxoma
    • The majority seem to be located in the left atrium and are pedunculated.  They may prolapse through the mitral valve during diastole and prevent ventricular filling.
    • They can be smooth/firm or friable/irregular.  The latter can often present with systemic embolism.
  • Papillary fibroelastomas
    • Avascular papillomas usually occurring on the mitral or aortic valves.  They don’t often cause any valvular disruption but present instead with embolic disease.  Usually found in older people.
  • Rhabdomyomas
    • Most common heart tumour in children, and commonly associated with Tuberous Sclerosis.  Most are located intramurally or free wall of the left ventricle, and can affect the conduction system.  They can regress with age but a minority can develop tachyarrhythmias/heart failure due to outflow obstruction.
  • Other types of benign tumours include fibromas (often found in childhood and associated with renal tumours or basal cell naevus syndrome); Haemangiomas; Teratomas; Lipomas; Paragangliomas (including phaeochromocytomas) and Pericardial cysts)
• Malignant tumours
  • Sarcoma
    • 2nd most common primary tumour and most common malignant primary- it affects mainly middle-aged adults and originate in the right atrium, involving the pericardium and can cause right ventricular inflow obstruction and pericardial tamponade.  It frequently metastasises to the lung.
  • Other types include lymphoma and pericardial mesothelioma.
• Metastases
  • Most common although rare in general- usually from the lung, breast or kidney cancers.

Symptoms/Signs

• Many patients can be asymptomatic (found incidentally on imaging)
• Symptoms largely depend on the size, location and character of the tumour, but there may be a triad of features
  • Valvular obstruction
    • I.e. left or right sided heart failure
      • Left sided: shortness of breath; orthopnoea; pulmonary oedema
      • Right sided: peripheral oedema; ascites; raised JVP
  • Embolic events
    • Most tend to be left sided and therefore systemic embolic events
      • Stroke or tissue/organ ischaemia
  • Constitutional symptoms
    • Weight loss, fatigue, weakness, fever, arthralgia
    • May resemble infective endocarditis
• A diastolic murmur may be audible with myxomas, and an audible ‘tumour plop’ may be heard too as the tumour passes through the mitral valve.

Investigation

• Due to the rarity of these tumours- often symptoms are investigated for other causes and diagnosis may be delayed
• Echocardiogram may detect tumours
• Cardiac MRI is used to stage tumours

Management

• Depends on the tumour type, individual patient and predicted outcome
• In general
  • Benign primary tumours should be offered excision (note that this is entirely dependent on individual and their functional status
  • Malignant primary tumours are general palliative
  • Metastatic disease should be treated depending on the primary