Cardiac Tumors

Overview

CTs (cardiac tumors) are extremely uncommon. Primary cardiac tumors are significantly less prevalent than metastatic tumors, with a frequency of about 0.02 percent in autopsy series. The most common benign tumor is myxoma (50–70%), while angiosarcoma is the most common malignant tumor (30%), followed by rhabdomyosarcoma (20 percent ).

Cardiac metastases occur in around 10% of all cancer patients, but they are rarely clinically noticeable. They can, however, induce a wide range of clinical signs and symptoms that can be mistaken for many other more prevalent cardiovascular and systemic disorders. When a CT is suspected, echocardiography remains the first diagnostic approach. On the other hand, CTs commonly occur unexpectedly during an echocardiographic evaluation.

Cardiac tumors classification

Cardiac tumors are rare and can be either primary or secondary. Autopsy estimates the incidence of primary cardiac malignancies to be between 0.001 and 0.3 percent.

They can be classified into three clinicopathological groups: 

• benign congenital tumors; 
• benign acquired tumors; and 
• malignant tumors. 

The majority of initial cardiac tumors are benign (almost 90%). Myxoma is the most prevalent primary cardiac tumor, accounting for almost half of all primary cardiac tumors. Malignant cardiac tumors are uncommon, accounting for about 10% of all primary heart tumors. Sarcomas, particularly angiosarcomas, are among them. Tumors that spread to the heart are far more prevalent than original cardiac tumors, yet they are only surgically removed in a minority of cases.

Epidemiology

Secondary malignant lesions, which occur in around 0.001 to 0.3 percent of autopsies, are far more common than primary cardiac malignancies. Almost all initial cardiac tumors that are surgically removed are benign. Cardiomyxomas were once thought to be the most prevalent primary benign cardiac neoplasm in adults, accounting for roughly 80% of benign tumors. Secondary malignant disease of the heart and pericardium is 30 to 1000 times more prevalent than primary cardiac malignant disease, according to certain estimations.

The incidence of metastatic involvement was 0.4 percent; cardiac involvement might be as high as 20% in patients with proven malignancy. Direct tumor extension, venous/lymphatic spread, or arterial metastasis are the most common ways for cancer to spread to the heart. Lung, breast, esophagus, stomach, kidneys, melanoma, lymphoma, and leukemia are the most prevalent underlying malignant illnesses with subsequent cardiac involvement.

Etiology 

Some cardiac tumors arise as a result of genetic predispositions or as part of genetic disorders, which could have consequences for genetic counseling and targeted therapy.

• Tuberous sclerosis, an autosomal dominant condition characterized by the development of hamartomas in many organs, is linked to cardiac rhabdomyomas.
• Gorlin syndrome is an autosomal dominant illness marked by developmental defects and a proclivity for neoplasia. Cardiac fibromas may be linked to Gorlin syndrome.
• Cardiac myxomas could be a symptom of the Carney syndrome, which is an autosomal dominant disorder.
• Histiocytoid cardiomyopathy can run in families, although the genetic defects that cause it are unknown.
• Most cardiac undifferentiated sarcomas have a genetic profile similar to pulmonary artery intimal sarcomas, with recurrent mutations in the MDM2, PDGFRA, and CDKN2A genes.
• After cardiac instrumentation and thoracic irradiation, papillary fibroelastomas have been documented.

Primary Cardiac Tumors

Benign Tumors

1. Myxoma

• In adults, this is the most frequent benign tumor. The left atrium is the most common location (80%), followed by the right atrium and the ventricles on rare occasions.
• They usually appear next to the fossa ovalis membrane, near the interatrial septum.
• Women are more likely to develop them, and they usually appear in the sixth decade of life.
• The majority of cardiac myxomas are sporadic, but there have been reports of family instances.
• Solid and villous gross subtypes have been identified macroscopically. Solid tumors are globular or elongated, with a smooth, glossy, and occasionally undulant surface. The papillary surfaces of villous tumors are uneven and often friable.
• The presence of the so-called myxoma cell (or lepidic cell), a cytologically bland cell with eosinophilic cytoplasm and an oval or round nucleus, is the only histological feature. Spindle cells that are stellate, ovoid, or plump can be found alone or in groups. The cells are usually found in a mucopolysaccharide-rich myxoid matrix. Near the stalk or the base of the lesion, large thick-walled vessels are common.
• Embolization is widespread due to a lack of robust structure.

2. Lipomas

• This is the second most common type of primary cardiac mass. Approximately 0.5 percent of all cardiac tumors
• The sub-endocardium and sub-epicardium of the left ventricle, right atrium, and interatrial septum are more commonly affected.
• Lipomas are solitary masses that are golden, soft, smooth, well-circumscribed, and encapsulated under the microscope.
• The tumors are composed of white fat with a fibrous capsule and some fibrous septa, with minimal to no atypia in the fat cells.
• Lipomas are usually asymptomatic, although they can cause arrhythmias, conduction system dysfunction, and heart failure symptoms depending on their location.

3. Papillary fibroelastoma

• Endocardial papilloma is another name for endocardial papilloma.
• Valve tumors are the most common (75 percent), with the aortic valve being the most common location, followed by the mitral valve.
• Endocardial cells are the source of this substance; 95% of it is located in the left-sided chambers.
• Men are more likely to be diagnosed in their sixth to seventh decades of life.
• Papillary fibroelastomas have a spherical, white appearance and a soft substance under the microscope. Multiple delicate fronds unroll in solution, giving the tumor a "sea anemone-like" appearance. The tumors usually have a single stalk connected to the endocardium and range in size from 2 to 50 mm.
• Papillary fibroelastomas are made up of narrow avascular papillary fronds with complicated branching patterns under the microscope. The collagen and elastic fiber arrangement resembles the tendinous cords of the atrioventricular valves histologically.
• Embolization is a regular occurrence. There is also valvular insufficiency or blockage. Symptoms of heart failure and a new murmur on physical examination are also common.

4. Rhabdomyomas

• The most frequent cardiac tumor in children occurs before they reach the age of one year. A whopping 86 percent of cardiac rhabdomyomas have been linked to tuberous sclerosis.
• It can manifest in a variety of ways, but it most usually affects the ventricles.
• Rhabdomyomas are well-defined, unencapsulated, whitish or grey nodular masses that range in size from millimeters to several centimeters on a macroscopic scale.
• Rhabdomyomas are well-defined nodules of enlarged vacuolated cells with transparent cytoplasm due to glycogen accumulation on a microscopic level. The appearance of so-called spider cells is a distinguishing trait.
• The occlusion of the cardiac chambers and conduction system disturbances, such as heart block or ventricular tachyarrhythmias, cause symptoms.
• Except in situations of blockage or arrhythmias, most of these tumors resolve spontaneously after birth, and excision is rarely required.

5. Fibromas:

• With a little male predominance, this is the second most common cardiac tumor diagnosed in children.
• Are intramural tumors that mostly affect the left ventricle's septum.
• Cardiac fibromas are well-circumscribed, solid, generally solitary white masses that resemble fibromatosis or uterine leiomyomas on the macroscopic level. On chopped sections, they usually have a whorled appearance.
• Cardiovascular fibroma is made up of monomorphic fibroblasts with little or no atypia under the microscope. The edges of the margins permeate the heart muscle.
• The signs and symptoms are linked to heart failure symptoms and are linked to an increased risk of ventricular tachyarrhythmias and sudden cardiac death.

Malignant Tumors

Cardiac Sarcomas

Angiosarcoma

• The most frequent primary malignant tumor in the fourth decade of life, with a rising prevalence.
• The most common location is the right atrial chamber.
• Angiosarcomas appear as dark brown or black hemorrhagic masses with infiltrating boundaries under the microscope.
• Angiosarcoma infiltrates heart muscle without defined borders under the microscope. The vascular channels are uneven, anastomosing, and sinusoidal, with pleomorphic lining cells displaying mitotic patterns frequently.
• Patients with angiosarcoma have a dismal prognosis.

Secondary Cardiac Tumors

Metastatic tumors

Metastases can enter the heart through the lymphatic system, as well as the arterial and venous systems. Lymphatic spread is widespread in lung and breast malignancies, as well as some sarcomas and lymphomas; it frequently produces pericardial effusion and can result in "tumor encasement of the heart," which is characterized by constriction.

Because pericardial drainage will not ease symptoms in individuals with suspected cardiac tamponade, it is necessary to keep in mind the possibility of tumor encasement (with or without effusion). Leukemia, melanoma, and various lymphomas commonly spread intracoronary; the metastases are usually intramural, and cases of acute coronary syndrome have been reported.

Tumors of the genitourinary system frequently penetrate the inferior vena cava, grow rapidly in a symbiotic relationship with superimposed thrombus (so-called "tumor thrombosis"), and reach the right atrium. Melanoma has a high proclivity for cardiac involvement, but lung and breast carcinoma, soft-tissue sarcoma, and renal malignancy are all typical origins of heart metastases.

The heart is frequently affected by leukemia and lymphoma. Lung carcinoma (35 percent–40 percent), hematologic malignancies (10–20 %), and breast cancer are the most common secondary tumors of the heart seen in clinical practice, based on both the prevalence of the underlying tumor and the propensity to metastasis (10 % )

Cardiac tumors symptoms

CTs are typically associated with cardiac failure, arrhythmias, or embolic events. Heart failure and embolic events are more common in intracavitary tumors, whereas arrhythmias are more common in intramural tumors. Intracavitary tumors, on the other hand, may have a point of attachment at the cardiac walls and thus be arrhythmogenic; intramural tumors, on the other hand, may bulge and partially obliterate a cardiac chamber or interfere with a ventricle's mechanical performance and thus cause heart failure if large enough.

As a result, the precise anatomical position, size, and interactions with surrounding tissues of tumors are more directly associated to their unique signs and symptoms than their histological kind. Tumors in the atria or atrioventricular valves can impede blood flow into the heart, causing stenosis of the mitral or tricuspid valves to appear. Paroxysmal heart failure, syncope, dyspnea, and embolism are common complications of mobile, pedunculated neoplasms. Tumor infiltration into the ventricular walls can cause symptoms that are comparable to hypertrophic or restrictive cardiomyopathy, with heart failure dominating the clinical picture.

Pseudoischemic alterations in the associated leads may be visible on ECG. SVC syndrome can develop from expansion into the superior vena cava (SVC). Tumor infiltration of the neural pathways or the conduction system can result in irregular heartbeat and, in particular, atrioventricular block (which is especially common in fibromas); in some cases, sudden cardiac death is the initial symptom of a CT.

CTs are frequently ordered when a patient has experienced a stroke, a peripheral embolism, or a pulmonary artery embolism, all of which are caused by detached tumor tissue or the mobilization of thrombotic deposits. It's also important to consider the likelihood of paradoxical embolisms. As a result, all embolic material pieces collected during diagnostic investigations should be histologically examined. Myxomas, in particular, are prone to causing embolisms due to their gelatinous composition.

Diagnosis

The properties and origin of the mass can be determined using a variety of imaging methods. Due to the difficulty of histological assessment of cardiac masses, most of these tumors will not be diagnosed with certainty unless they are removed.

The following imaging techniques are mostly used to determine cardiac masses:

Echocardiogram

The first diagnostic procedure is usually echocardiography. The differential diagnosis for a cardiac mass found on echocardiography includes thrombi, benign tumors, and malignant tumors. The following variables must be taken into account: location, implant, additional structures involved, and echogenicity. A thrombus is a broad-based mass in an enlarged left atrium in a patient with atrial fibrillation and/or significant mitral stenosis.

Thrombi in the right chambers are frequently an embolus or extension of a deep venous thrombosis; they are serpentine-like and very migratory. The most frequent benign tumors (myxomas and PFEs) are pedunculated, with insertions on the left side of the interatrial septum (myxomas) or a heart valve in the majority of instances (fibroelastomas). The expansion of an intracardiac or pericardial mass in the cardiac wall is usually a hallmark of malignancy; malignant tumors are often broad-based and may have several sites.

Rhabdomyomas and fibromas, on the other hand, can grow within the ventricular wall. Echo contrast agents can be used to confirm the presence of an intracardiac mass and to further describe it based on the amount of contrast enhancement, which is a vascularity marker, as well as to assess myocardial infiltration. As a result, hyperenhancement with contrast is seen in malignant and highly vascular tumors, whereas thrombi do not appear to enhance at all, and myxomas are only partially increased.

The uptake of the contrast agent by a CT is often delayed (a few minutes after injection) and persistent; qualitative and quantitative study of the reperfusion time has been shown to be beneficial in the differential diagnosis. To examine myocardial mass vascularization, low mechanical index contrast echocardiography is a simple, noninvasive cardiac imaging method.

The degree of contrast enhancement and time to opacification fluctuate greatly between cardiac masses and correspond to varying degrees of vascularization.

Cardiac MRI

Cardiac MRI is a good imaging technique for determining tumor size, location, and surrounding structures so that surgical removal can be planned.

The analysis of T1 and T2 signals can aid in determining the mass's composition. The use of contrast, comparable to an echocardiography, can help determine whether a cardiac thrombus or a tumor is present.

CT Scan 

This imaging research can be used to evaluate cardiac mass, neighboring structures, and the nature of the mass by evaluating x-ray attenuation. This imaging study can detect calcification of the mass and can also analyze tiny masses.

Left Heart Catheterization with Coronary Angiogram

The blood supply and surrounding structures to the tumors can be determined by left cardiac catheterization. The procedure can also be used to assess whether the tumor has spread to the epicardial arteries, and ventriculography can be used to determine whether the tumor has spread into the ventricular chamber.

Biopsy and Histological Evaluation

In vivo intracardial biopsy is a high-risk technique performed only by expert surgeons in high-volume hospitals. Tumors on the right side are more likely to be biopsied to determine the tumor's histology.

During a left-sided tumor biopsy, there is a higher risk of perforation and systemic embolization. The success rate of a biopsy is increased by imaging-guided biopsy, and a good tissue specimen is obtained for determining the histological origin.

The underlying nature of malignancies can also be determined using cytology from pericardial fluid. Finally, the type of tumor is determined through surgical removal of the tumor, histological assessment, and fluoroscopy.

Transesophageal echocardiography

When the cardiac mass is in the atria, transesophageal echocardiography looks to be preferable to transthoracic echocardiography. Improved resolution of the tumor and its attachment, the ability to detect some masses not visible on transthoracic echocardiography, and the ability to examine the pulmonary veins, venae cavae, and the infiltration of the pulmonary veins for the left atrial masses are all potential advantages of transesophageal echocardiography.

It is widely utilized for intraoperative (transvenous biopsy or cardiac surgery) monitoring and should be explored when the transthoracic study is poor.

Management

Primary Cardiac Tumors

Benign Tumors

Myxoma

• Because of the increased danger of embolization caused by the myxoma's friable nature, surgical excision is required.
• To avoid recurrence, it is critical to have tumor-free margins after resection.

Lipomas

In the absence of symptoms or arrhythmias, there is no need to intervene.

Papillary Fibroelastoma

Patients with large mobile masses or evidence of embolization should have their left-sided papillary fibroelastomas surgically resected.

Rhabdomyoma

Except in situations of blockage or arrhythmias, most of these tumors resolve spontaneously after birth, and excision is rarely required.

Fibroma

Complete surgical resection when is feasible is the recommendation.

Cardiac Sarcomas

The majority of sarcomas have a dismal prognosis; however, several studies have showed that complete surgical excision of the sarcoma improves survival rates when compared to those who do not have surgery. After diagnosis, surgical removal is recommended.

Secondary Cardiac Tumors

Treatment of the underlying cancer will help prevent cardiac invasion, however cardiac invasion or metastasis is typically a bad prognostic factor.

Pericardial effusion is treated with pericardial drainage, and if re-accumulation occurs, a pericardial window can be performed.

Differential Diagnosis

Other more common features such as thrombus or vegetations are important differential diagnosis for cardiac masses. The clinical context is critical in these circumstances to pinpoint the source of the cardiac mass. In the case of infection, the presence of intracardiac or prosthetic implants raises the suspicion of vegetations.

Heart failure symptoms in patients with an underlying malignancy can also be attributable to chemotherapy cardiotoxicity, which must be evaluated before evaluating whether the main tumor has spread or invaded. Infectious disorders can cause intracardial and pericardial masses or effusions, necessitating a microbiological examination.

How long can you live with a heart tumor?

The kind of cardiac tumors and mechanical abnormalities (obstruction/insufficiency) determine their prognosis.

Primary benign cardiac tumors have the best prognosis unless numerous embolizations occur, which can result in multiple strokes with varying neurological involvement and physical limitations, especially when systemic. A similar situation occurs when a tumor produces mechanical irregularities in the conduction system, resulting in life-threatening arrhythmias or valvular disease symptoms such as syncope or heart failure.

Malignant tumors, particularly initial tumors, have the lowest long-term prognosis. In the absence of surgical excision, survival after the first year after diagnosis is poor.

Secondary cardiac tumors have a bad prognosis, owing to the fact that the initial tumor is most certainly progressed, with multiple regions of metastasis conceivable. In this circumstance, there is also a mechanical compromise.

Complications

Mechanical complications arise as a result of cardiac tumors. Embolization producing strokes is a common complication that might present as a stroke and later be discovered during a stroke workup.

When the mass is close to the leaflets, valvular illness, such as blockage or insufficiency, is common. Syncope can occur when a mass obstructs blood flow, resulting in hypoperfusion of the brain and coronaries and predisposing to tachyarrhythmias.

Electrical anomalies such as atrioventricular block, total heart block, and ventricular tachyarrhythmias can be caused by masses near the conduction system in the epicardium and myocardium. Hypotension, shortness of breath, and even cardiac tamponade can occur as a result of pericardial involvement and pericardial effusion.

Conclusion 

Primary CTs are typically benign and have a fair prognosis, but sarcomas are the most common malignant primary CTs and have a bad prognosis.

Other conditions such as rheumatic valvular disease, endocarditis, myocarditis, pericarditis, cardiomyopathies, and congenital heart disease, as well as pulmonary conditions such as pulmonary emboli, pulmonary hypertension, and interstitial lung disease, cerebrovascular disease, and vasculitis, can be misdiagnosed as CTs. Noninvasive cardiovascular imaging techniques, particularly echocardiography, have advanced.

CT and MRI scans have substantially aided diagnostic evaluation and allowed for the quick detection of intracardiac masses. When identifying the diagnosis and designing therapy, a multidisciplinary approach is critical.