Cardiac tumors are uncommon and can be primary or metastatic. Primary cardiac tumors are rare, and the incidence is from 0.001 to 0.3% by autopsy. They can be classified into three clinicopathological groups: 1. benign congenital tumors; 2. benign acquired tumors and 3. malignant tumors. Nearly 90% of primary cardiac tumors are benign. Myxoma is by far the most common primary tumor of the heart accounting for slightly more than a half of all primary cardiac tumors. Malignant cardiac tumors are rare and account for 10% of all primary cardiac neoplasms. They include sarcomas especially angiosarcomas. Tumors that metastasize to the heart are much more common than primary cardiac tumors but are rarely surgically excised.
Some cardiac tumors occur in the setting of genetic predispositions or are part of genetic syndromes; this may have implications for genetic counseling and therapeutic implications for targeted therapies.
Primary cardiac tumors are much rarer than secondary malignant lesions occurring in about 0.001-0.3% of the autopsies. Almost 90% of primary cardiac tumors excised surgically are benign. Until recently, cardiac myxomas had wide recognition as the most common primary benign cardiac neoplasm of adulthood, representing nearly 80% of benign tumors. Secondary malignant disease of the heart and pericardium is considerably more common than primary cardiac malignant disease; in some estimates, it is 30 to 1000 times more common. In a random autopsy series, the frequency of metastatic involvement was 0.4%; in patients with confirmed cancer, cardiac involvement can be as high as 20%. Spread to the heart is generally via direct tumor extension, venous/lymphatic spread, or arterial metastasis. The most common underlying malignant diseases with secondary cardiac involvement are carcinoma of the lung, breast, esophagus, stomach, kidneys, melanoma, lymphoma, and leukemia.
Primary cardiac tumors
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Secondary cardiac tumors
The clinical symptoms of different cardiac tumors are often non-specific and insidious, which can delay diagnosis and surgical management.
The symptoms may relate to processes in the heart such as valvular dysfunction, pericardial effusion with tamponade, intracardiac blood flow obstruction, arrhythmia, and congestive heart failure.
An increasing proportion of cardiac tumors induce no symptoms at all and become obvious only as an incidental finding.
The clinical manifestations depend on the tumor's size, anatomical location, growth, and invasiveness.
Multiple imaging modalities can be useful to the determine the mass characteristics and origin. Ultimately, due to the complexity of histological evaluation of cardiac masses, most of these tumors, unless removed, won't be diagnosed with certainty.
The following imaging techniques are mostly used to determine cardiac masses:
EKG is an important imaging technique that is likely to be the one that makes the diagnosis of the cardiac tumor. Sensitivity and specificity are as high as 90%
Can be performed easily at the bedside and if further detail is necessary, the use of transesophageal echocardiogram can help to determine further characteristics and location of the cardiac tumor.
This modality can determine, size, mobility, and extension of the tumor and relation with neighboring structures and to determine dynamics relates to the mass as obstructions or valvular insufficiency.
Use of transesophageal echocardiogram can also increase the visualization of small tumors not clear in the transthoracic echocardiogram.
Contrast echocardiography is also useful to differentiate between cardiac tumor versus cardiac thrombus.
Three-dimensional echocardiography is an additional feature to determine dimensions, shape and structural involvement of the tumor.
Cardiac MRI an excellent imaging modality to determine tumor size, location, adjacent structures to determine an approach for surgical removal.
Assessment of T1 and T2 signal can help to determine the composition of the mass.
Use of contrast, similarly as in echocardiogram, can evaluate the presence of cardiac thrombus versus a tumor.
This imaging study is useful for assessment of cardiac mass, adjacent structure and can determine the nature of the mass by evaluating the x-ray attenuation.
Calcification of the mass is also visible with this imaging study, and it can also evaluate small masses.
Left heart catheterization with coronary angiogram
Left cardiac catheterization can be helpful to determine the blood supply and adjacent structures to the tumors. The technique can also help to determine invasion of the tumor to the epicardial vessels, and with ventriculography one can determine the extension of the tumor into the ventricular chamber.
Biopsy and histological evaluation
In vivo intracardial biopsy is a risky procedure that is mostly limited done at high volume centers with experienced surgeons.
Right-sided tumors are more likely to be biopsied to determine the histology of the tumor.
Left-sided tumor biopsy has more risk for perforation and systemic embolization during the procedure.
Imaging-guided biopsy increases the success rate of a biopsy and also provides a good tissue specimen for determination of histological origin.
Cytology from the pericardial fluid can also be used to determine the underlying nature of tumors.
Ultimately, surgical resection of the tumor with histological evaluation and fluoroscopy are used to determine the type of tumor.
Primary Cardiac tumors
The majority of sarcomas have an overall poor prognosis; some studies have found an increase in survival rate with complete surgical resection of the sarcoma when compared with patients without surgical management. Surgical removal after diagnosis is the recommendation.
Secondary cardiac tumors:
Treatment of the underlying malignancy will help with cardiac invasion, but very frequently, cardiac invasion or metastasis is a poor prognosis factor.
Management of pericardial effusion is via pericardial drainage, and if re-accumulation occurs, one can perform a pericardial window.
Important differential diagnoses of cardiac masses are other more common findings as thrombus or vegetations. In these situations, the clinical scenario is vital to determine the origin of the cardiac mass.
The presence of intracardiac devices or prosthetic devices in the setting of infection increases the suspicious of vegetations.
Heart failure symptoms in patients with underlying malignancy can also be related to cardiotoxicity from chemotherapy, and this requires evaluation before determining possible metastasis or invasion of the primary tumor.
Infectious diseases can also produce intracardial and pericardial masses or effusion, and microbiological assessment is necessary.
The prognosis of the different cardiac tumors depends on their nature and mechanical disturbances (obstruction/insufficiency).
Primary benign cardiac tumors have the best prognosis, unless multiple embolizations occur, especially when systemic because this can cause multiple strokes with different neurological involvement and physical limitations. A similar situation occurs when the tumor causes mechanical abnormalities in the conduction system inducing arrhythmias that can be life-threatening or valvular disease-causing syncope or heart failure symptoms.
Malignant tumors, especially primary tumors are the ones with worst overall prognosis. Survival after the first year of diagnosis is low, especially in the absence of surgical excision.
Secondary cardiac tumors have a poor prognosis but mostly because the primary tumor is likely to be advanced with possible different areas of metastasis. Also, a mechanical compromise occurs in this scenario.
Complications due to cardiac tumor are mechanical.
Embolization causing strokes is a frequent complication that can present as stroke and later while doing stroke workup can find the cardiac mass.
Valvular disease, such as obstruction or insufficiency is common when the mass is adjacent to the leaflets. Syncope can occur when there is a blood flow obstruction due to the mass, causing hypoperfusion to the brain and the coronaries, also predisposing to tachyarrhythmias.
Presence of masses next to the conduction system in the epicardium and myocardium can generate electrical abnormalities as atrioventricular block, complete heart block, and ventricular tachyarrhythmias.
Pericardial involvement and pericardial effusion can cause a hemodynamic disturbance with hypotension, shortness of breath and even cardiac tamponade.
Patients with the diagnosis of cardiac masses need extensive evaluation to determine the etiology and prevent of decompensation.
Cardiac masses can be abnormal tissue that can be limited to the heart tissue and after removal can prevent mechanical complications.
The presence of a cardiac mass requires a multidisciplinary approach. The differential is enormous, and the diagnosis and management need to be prompt to lower the morbidity and mortality. Besides a cardiologist, a cardiac surgeon, electrophysiologist, an internist, and intensivist are essential in patient care. The overall prognosis depends on the type of mass and extent of myocardial involvement.