What is a cardiac tumor
Primary cardiac tumors are extremely rare, with an incidence of less than 0.1%. They are benign or malignant neoplasms that originate from the inner lining tissues, muscular layer, or pericardium of the heart.
Secondary or metastatic cardiac tumors are always malignant, more common than primary malignant tumors, and have spread from another part of the body to the heart. The most common primary sites are the lung, breast, kidney, soft tissues (sarcomas), blood (leukemias), lymphatic tissue (lymphomas), or skin (melanomas).
Cancers that affect the chest, such as lung or breast cancer, can reach the heart through direct invasion, often in the membrane surrounding the heart (the pericardium). Other cancers can also reach the heart muscle through the bloodstream or lymphatic system.
Only a small portion of cardiac tumors are malignant: 25%, while 75% of cases are benign cardiac tumors.
Subtypes of benign primary cardiac tumors
- Myxoma – is the most common, accounting for 50% of all primary cardiac tumors. It is two to four times more common in women than in men. Approximately 75% of myxomas arise in the left atrium, with the remainder occurring in other heart chambers, either as a solitary tumor or (less commonly) at multiple sites. Its diameter can reach 15 cm³, and the cell that can give rise to it is unknown;
- Papillary fibroelastoma – are avascular papillomas that occur in cardiac valves in more than 80% of cases and are more common on the left side of the heart;
- Rhabdomyoma – the most common cardiac tumor in infants and children, accounting for 60% of cases. They are usually multiple tumors. There is a very close relationship between rhabdomyomas and tuberous sclerosis: sclerosis is reported in up to 80% of cases of patients with this tumor, and the tumor is detected in up to 72% of cases of patients who had previously been diagnosed with tuberous sclerosis;
- Fibroma – is also more frequent in children and is usually a solitary tumor. Its diameter can reach 10 cm;
- Hemangioma – extremely rare, with a diameter of 2 to 4 cm, and may regress spontaneously, although in children its course may be unfavorable;
- Lipoma – exclusive to adults, but in a very wide age range. It can lead to the development of arrhythmias.
Subtypes of malignant primary cardiac tumors
- Angiosarcoma – a tumor that predominantly occurs in males and mainly affects the right atrium (80% of cases). It can metastasize to the pleura, mediastinum, and lungs;
- Rhabdomyosarcoma – manifests in adult men, originates in striated muscle, and affects any of the heart chambers;
- Pericardial mesothelioma – rare, affecting all age groups, more commonly in men than women. It can metastasize to the spine, adjacent soft tissues, and brain;
- Lymphoma – extremely rare, usually occurs in patients with HIV or other diseases that lead to immunodeficiency.
Subtypes of metastatic (malignant) cardiac tumors
- Melanoma – the reason is unknown, but melanoma has a predilection for cardiac metastases: half of the cases of disseminated melanoma throughout the body have deposits in cardiac tissue in autopsy findings;
- Lung and breast carcinoma – are the most common sources of metastasis to the heart, able to spread to the pericardium and cause pericardial effusions;
- Leukemia – when leukemia metastasizes, it usually occurs in the heart, silently and sometimes with large deposits and hemorrhagic pericardial effusion;
- Lymphoma – also tends to metastasize to the heart in an asymptomatic manner, forming small intramyocardial masses.
Symptoms and signs of cardiac tumor
The symptoms of malignant cardiac tumors are essentially the same as those of benign cardiac tumors, with malignant tumors tending to worsen more rapidly as they grow more quickly.
In general, symptoms include:
- Sudden onset of heart failure (with shortness of breath and fatigue);
- Cardiac arrhythmia (causing palpitations, weakness, or fainting);
- Bleeding and accumulation of fluid in the pericardium (which can interfere with heart function and cause cardiac tamponade).
In metastatic cardiac tumors, symptoms of the original tumor and metastases occur simultaneously. For example, lung cancer with metastasis to the heart may have symptoms such as difficulty breathing, fatigue, and coughing up blood.
The most specific symptoms depend on the type of tumor, its location, size, and fragility.
Diagnosis of cardiac tumor
When symptoms raise suspicion for a specialist, the diagnosis of cardiac tumors is made through imaging tests: echocardiography, magnetic resonance imaging, and computed tomography.
- Echocardiography is the test that confirms the diagnosis. Transesophageal echocardiography (TEE) is better for visualizing atrial tumors, while transthoracic echocardiography works better for detecting ventricular tumors.
- Cardiac magnetic resonance imaging is used to identify tissue characteristics of the tumor and thus find clues about the type of tumor.
- Contrast-enhanced cardiac computed tomography can provide detailed information with superior spatial resolution
Biopsy is not usually performed on cardiac tumors because imaging tests can differentiate between benign and malignant tumors. Additionally, there is a risk of unintentional dissemination of neoplastic cells in patients with a primary malignant tumor undergoing a cardiac tumor biopsy. In cases of suspected primary tumors, surgery is preferred over biopsy.
For metastatic cardiac tumors, additional tests are performed to find the original cancer (unless its location is already known).
Treatment of cardiac tumors
Benign primary cardiac tumors are usually treated with surgical excision – the procedure is only not performed if another disease contraindicates surgery. The exception is rhabdomyoma, which mostly regresses spontaneously and does not require treatment.
The treatment of malignant primary cardiac tumors is generally palliative (radiotherapy, chemotherapy, and care for complications, for example), as the prognosis is reserved, meaning the likelihood of improvement or cure is small.
For metastatic cardiac tumors, treatment depends on the origin and type of tumor. It may include systemic chemotherapy or palliative therapy, and the prognosis is also reserved.
Prevention of cardiac tumor
Since there are no associated risk factors for cardiac tumors, it is not possible to prevent their development.
