Cardiac tumors

Cardiac tumors

Cardiac tumors are rare. They can occur anywhere in the heart or surrounding tissue. Tumors can be localized in the myocardium, pericardium, perivalvular (adjacent to the valves), etc. Cardiac tumors cause nonspecific symptoms that depend on the size of the tumor, localization, hemodynamic effects and possible impact on the coronary arteries. The tumors can be asymptomatic for a long time and be detected randomly when investigating other conditions. More dramatic onset of symptoms can be seen in arrhythmogenic tumors of the myocardium; in these cases, the tumor can debut with ventricular arrhythmias that result in asystole and sudden death.

In echocardiography, tumour should be suspected in case of detection of ecotdense tissue masses. However, the majority of all ecotate masses are vegetations (endocarditis) and thrombi. Only a minority of all ecotaceous masses are tumors. Most of all cardiac tumors are secondary, and the primary cardiac tumors, generally, are benign.

Primary and secondary cardiac tumors

• Primary cardiac tumors, which constitute a minority of cardiac tumors, occur in the heart tissue. Approximately 80% of all primary tumors are benign, and the remaining ones are malignant. • Secondary cardiac tumours have spread to the heart by metastasis or invasion from surrounding tissue.

Differential Diagnostics

There are several differential diagnoses in the case of cardiac masses. The characteristics of the patient, the size and localization of the mass are indicative in diagnostics. A patient who exhibits an ecotdense mass entrenched in the endocardium with impaired mobility (for example, after myocardial infarction), most likely has a parietal thrombus. The presence of ecotdense masses on valves should lead to suspicion of endocarditis (the masses are vegetations). The risk of endocarditis is especially high for patients with valve prostheses.

Investigation of cardiac masses

Detection of cardiac masses with echocardiography most often entails additional investigation, which is aimed at clarifying the genesis of the mass. Transesophageal echocardiography (TEE), magnetic resonance imaging (MRI of the heart) and computed tomography (DT of the heart) are appropriate investigative options. Three-dimensional (3D) echocardiography is likely to have increased significance in these studies in the future.

Hemodynamic effects of cardiac tumors

The hemodynamic effect of the tumor depends on its size and location. Tumors can reduce cardiac output by causing obstruction or valve dysfunction. Tumors that grow invasively in the myocardium can cause arrhythmias, which in turn can cause hemodynamic effects (impaired cardiac output).

Benign primary cardiac tumors

Most (75%) of all primary cardiac tumors are benign. Among adults, most of them are myxomas and next papillary fibroelastoma is most common. Among children, rhabdomyoma is most common.

Myxoma

Myxoma is the most common primary cardiac tumor. These tumors most often debute at the age of 30-60 years and are more common among women. Approximately 80% of all myxomas are localized in the left atrium (most of them originate from the atrial septum). In 15 -20% of cases, the tumor is localized in the right atrium. Myxoma is rare in the valves and ventricles.

Myxoma, generally, is mobile structures. Polypoid myxomas are large; they have a smooth surface and a nucleus that often exhibits cavities, which consist of hemorrhages in the tumor. Polypoid myxoma usually causes haemodynamic complications due to obstruction. Papillary myxomas are small; they have a more stretched appearance and most often exhibit multiple villi. These myxomas are more likely to embolize (Cardiac Thromboembolism).

There are genetic syndromes that result in the emergence of multiple myxomas.

Papillary fibroelastoma

Papillary fibroelastoma is benign primary tumors affecting adults. These tumors most often occur in the aortic valve and the mitral valve. generally, tumors are 2 to 40 mm. They usually have a stalk and are very mobile. The structure of the tumor is reminiscent of a sea anemone. Although most fibroelastomas are located on the valves, they usually cause no or only small valve dysfunction. However, papillary fibroelastoma carries a risk of thromboembolic events (TIA, stroke).

Left-sided fibroelastoma that is >1 cm is usually removed operatively. Right-sided are removed if they are large and entail hemodynamic complications, or if they pose a risk of thromboembolism (for example, through the persistent oval foramen with right to left shunt).

Rhabdomyoma (rhabdomyoma)

Rhabdomyoma is the most common primary tumor among children and the tumor is most often detected in the first year of life. These children often have tuberous sclerosis. Rhabdomyoma is rare among adults.

Rhabdomyoma is most often localized on the wall of the ventricle, alternatively on the mitral or tircuspid valve. Tumors are seen on echocardiogram as small, well-delimited tubers or stemmed masses. Rhabdomyoma can be embedded in the myocardium.

Rhabdomyoma most often goes into spontaneous regress and most often does not require treatment.

Fibromium

Fibroma is rare but affects both adults and children. These tumors are well-delimited, solid, high-echogenic masses inside the myocardium. Fibroma may be calcified.

Most fibromas are localized on the free wall of the left ventricle, anterior wall or septum. However, the growth in the ventricular cavity seen, which can lead to obstruction and heart failure. Fibroma growing in the myocardium can provoke arrhythmias.

Fibroma rarely goes into spontaneous regress and usually needs surgery removed. People with Gorlin's syndrome have multiple basal cell carcinomas and fibromas of the heart.

Lipoma

Cardial lipoma consists of benign adipose tissue. They occur most often in the subendocardium or on the heart valves. Most often, the lipoma is a couple of millimeters in diameter, but they can become several centimeters. On echocardiograms, lipomas appear as immobile, broad-basal structures that are well delimited to the environment. The contents are homogeneous and there are no calcifications. Lipomas in ventricular cavity are echo tight, while the lipomas of the pericardium are ecophilious.

Lipoma, generally, is asymptomatic. They can give symptoms through arrhythmias or valve dysfunction. Epicardially located lipomas can cause compression of the coronary arteries, thereby causing myocardial ischemia and chest pain . Since lipoma has a tendency to grow, surgery may be necessary.

Lipomatous hypertrophy of the atrial septum

A special form of fat deposits is sometimes seen in the atrial septum and this is especially common among the elderly and overweight. These fat deposits are seen mainly in the proximal and distal parts of the atrial septum. Fat deposits are not tumors and they rarely need to be addressed.

Other benign primary tumors of the heart

In the heart, albeit very rarely, hemangiomas, tumors of the AV node and teratoma occur. Hemangioma can occur anywhere in the heart (myocardium, pericardium, heart valves). Teratoma occurs in the pericardium.

Malignant tumors of the heart

Approximately 20% of all primary cardiac tumors are malignant. These are much more common on the right half of the heart, where almost 50% of tumors are malignant. Malignancy is usually accompanied by invasiveness, rapid growth and hemorrhagic pericardial deffusion.

Sarcoma of the heart

Sarcoma is the most common malignant primary tumor of the heart. The average age at debut is 40 years. Sarcoma most often affects the left atrium. The tumor has a wide base with varying echogenicity. Sarcoma has no stalk. These tumors tend to metastases, especially to the lungs.

The most common types of sarcoma are angiosarcoma and rhabdomyosarcoma . Less common are leiomyosarcoma, osteosarcoma, fibrosarcomaand undifferentiated sarcoma. All sacromas grow rapidly and metastasize early.

Lymphoma of the heart

Lymphoma often metastasizes to the heart. Autopsy studies show that 16% of patients with Hodgkin's lymphoma and 18% of patients with non-Hodgkin's lymphoma have metastases in the heart.

Lymphoma may also occur in the heart, especially B-cell lymphoma, and this is seen in transplanted patients and other immunosuppressed patients. Lymphoma most often affects the right half of the heart, especially the right atrium.

Lymphomas appear as homogeneous infiltrates on ultrasound. They can, depending on their size and localization, cause extensive hemodynamic disorders.

Mesothelioma (Mesothelioma)

Mesothelioma (malignant) makes up about 50% of primary tumors of the pericardium. Other tumors of the pericardium (teratoma, fibroma, lipoma) are benign. Mesothelioma can be seen in the pericardium, which usually contains an effusion.

Metastases to the heart

Autopsy studies show that up to 7% of all people with cancer have metastases in the heart. Metastases can reach the heart via the blood (hematogenous spread), by direct invasion from the environment (tumors in the mediastinum, lungs), via the lymph or via the inferior vena cava.

Lung cancer, oesophageal cancer, malignant melanoma, leukemia and lymphoma are the tumors that most often metastases to the heart. The highest propensity to metastases to the heart has malignant melanoma. In the case of metastases to the heart, the pericardium is also engaged, which leads to pericardial effusion.