What are the other Names for this Condition? (Also known as/Synonyms)

• Myxosarcoma of Heart

What is Cardiac Myxosarcoma? (Definition/Background Information)

• Cardiac Myxosarcoma is a very rare, high-grade malignancy of the heart. It is a form of sarcoma of the heart. They do not arise from cardiac myxomas, which are benign tumors affecting the heart
• When fibrosarcoma of the heart is present with lots of myxoid stroma, as observed by a pathologist under a microscope, it is known as a Cardiac Myxosarcoma
• The tumors are observed in adults in a wide age range. Currently, there are no identified risk factors of cause for Cardiac Myxosarcoma
• In a majority of cases, the tumors are observed to form in the left atrium (upper chamber of the heart). Large-sized tumors may cause chest pain, lung congestion, and breathing difficulties
• The treatment of Cardiac Myxosarcoma is undertaken through surgery. However, since it is difficult to remove the entire tumor, chemotherapy and/or radiation therapy may be necessary
• The prognosis of Cardiac Myxosarcoma is generally poor. The tumors are locally invasive and can metastasize to other body organs, in rare cases

Who gets Cardiac Myxosarcoma? (Age and Sex Distribution)

• Cardiac Myxosarcoma is a very rare tumor of the heart; they constitute 5-10% of the cardiac sarcomas
• The tumor occurs in adults - wider than the age range of malignant fibrous histiocytoma (MFH) tumors; MFH is seen in individuals between 20-80 years of age
• Some tumors have been observed in children too
• Both males and females are affected
• No racial or ethnic preference is noted

What are the Risk Factors for Cardiac Myxosarcoma? (Predisposing Factors)

• Currently, no specific risk factors are noted for the development of Cardiac Myxosarcoma

It is important to note that having a risk factor does not mean that one will get the condition. A risk factor increases ones chances of getting a condition compared to an individual without the risk factors. Some risk factors are more important than others.

Also, not having a risk factor does not mean that an individual will not get the condition. It is always important to discuss the effect of risk factors with your healthcare provider.

What are the Causes of Cardiac Myxosarcoma? (Etiology)

The exact cause and mechanism of formation of Cardiac Myxosarcoma is unknown.

• In general, it is known that cancers form when normal, healthy cells begin transforming into abnormal cells - these cancer cells grow and divide uncontrollably (and lose their ability to die), resulting in the formation of a mass or a tumor
• The transformation of normally healthy cells into cancerous cells may be the result of genetic mutations. Mutations allow the cancer cells to grow and multiply uncontrollably to form new cancer cells
• These tumors can invade nearby tissues and adjoining body organs, and even metastasize and spread to other regions of the body

What are the Signs and Symptoms of Cardiac Myxosarcoma?

The signs and symptoms of Cardiac Myxosarcoma are not very clearly marked/identified. They are based on the location of the tumor in the heart. Small tumors may not present any signs and symptoms. In such cases, the tumors may be discovered incidentally.

The features of Myxosarcoma of Heart may include:

• A majority of the tumors are located in the left atrium; other locations include the right atrium and ventricles (lower chambers of the heart)
• The tumor may intrude into the pericardium, so it can be confused with mesothelioma
• The presence of soft tumor that appears like a polyp
• Since mostly the left side of the heart is affected by the tumor, the signs and symptoms include lung congestion, blockage of pulmonary vein, and narrowing/stenosis of mitral valve (due to compression effect of the tumor)
• Besides the above, chest pain, breathing difficulty, blood in cough, dizziness, and fainting may also be observed

How is Cardiac Myxosarcoma Diagnosed?

The diagnosis of Cardiac Myxosarcoma is established in the following manner:

• Complete evaluation of family (medical) history, along with a thorough physical examination; including examination of the heart, with special emphasis to signs such as abnormal heart sounds
• Transthoracic echocardiography (TTE): This procedure uses sound waves to create a motion picture of the heart movement
• Electrocardiogram (EKG or ECG): It is used to measure the electrical activity of the heart, to detect arrhythmias
• MRI scan and CT scan of the heart:
• Doppler ultrasound: Sound waves are used to measure the speed and direction of blood flow
• Tissue biopsy of the tumor:
  • A biopsy of the tumor is performed and sent to a laboratory for a pathological examination. A pathologist examines the biopsy under a microscope. After putting together clinical findings, special studies on tissues (if needed) and with microscope findings, the pathologist arrives at a definitive diagnosis. Examination of the biopsy under a microscope by a pathologist is considered to be gold standard in arriving at a conclusive diagnosis
  • Biopsy specimens are studied initially using Hematoxylin and Eosin staining. The pathologist then decides on additional studies depending on the clinical situation
  • Sometimes, the pathologist may perform additional studies, which may include immunohistochemical stains and molecular studies to assist in the diagnosis

Note:

• A differential diagnosis to rule out myxoma of the heart may be undertaken
• Due to the rarity of these tumors, it can cause diagnostic challenges during a frozen section biopsy

Many clinical conditions may have similar signs and symptoms. Your healthcare provider may perform additional tests to rule out other clinical conditions to arrive at a definitive diagnosis.

What are the possible Complications of Cardiac Myxosarcoma?

Complications due to Cardiac Myxosarcoma could include:

• Congestive heart failure, depending on the location of the tumor in the heart
• Increased risk for thromboembolism (blood clot obstructing a blood vessel)
• Metastasis of the tumor to other sites in the body is generally rare. But if it takes place, then the following organs may be affected - lungs, lymph nodes, skin, and kidney
• Recurrence of the tumor after surgery, when the entire tumor is not removed
• Blood loss during invasive treatment methods may be heavy
• Damage of vital nerves, blood vessels, and surrounding structures during surgery
• Side effects from chemotherapy (toxicity), radiation therapy

How is Cardiac Myxosarcoma Treated?

The treatment measures for Cardiac Myxosarcoma may include a combination of the following:

• Surgery: Complete excision where possible is attempted; though, it is difficult for the heart tumor to be removed completely
• Radiation therapy and/or chemotherapy may be provided, when the tumor cannot be removed completely
• Embolization (clotting the vessels in the tumor) may be used to provide temporary relief from the symptoms and reduce blood loss during a surgical procedure
• Heart transplantation may be undertaken in some cases; when no metastasis has occurred and the primary tumor, which cannot be surgically removed, is confined to the heart
• Follow-up care with regular screening and check-ups are important

How can Cardiac Myxosarcoma be Prevented?

• Current medical research has not established a way of preventing the formation of Cardiac Myxosarcoma
• Due to its metastasizing potential and recurrence rate, regular medical screening at periodic intervals with blood tests, scans, and physical examinations, are mandatory for those who have already been treated for this tumor

What is the Prognosis of Cardiac Myxosarcoma? (Outcomes/Resolutions)

• The prognosis of Cardiac Myxosarcoma is generally poor; most cases with local invasion or metastasis are fatal despite surgery to remove the tumors. The prognosis is reported to be similar to malignant fibrous histiocytoma tumors
• Nevertheless, the prognosis depends on a combination of factors, such as:
  • Age of the individual
  • Grade of the tumor:
  • Tumor size and location
  • Its Ki-67 value - a protein found in cells that is a good indicator of how fast the tumor cells are growing. The Ki-67 value is determined by a pathologist and is usually mentioned in the pathology report
  • Response to treatment and medical therapy

Additional and Relevant Useful Information for Cardiac Myxosarcoma:

Primary tumors of heart are rare and they account for only 5% of heart tumors. Metastatic tumors to the heart are far more common.