Myxomas

ByLauren A. Baldassarre, MD, Yale School of Medicine;
Emmanuel Akintoye, MD, MPH, Yale School of Medicine
Reviewed/Revised Jun 2024
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A myxoma is a noncancerous primary heart tumor, usually irregular in shape and jellylike in consistency.

  • People may feel short of breath or faint, or they may have fever or weight loss.

  • Doctors confirm the diagnosis with echocardiography.

  • Surgery is needed to remove a myxoma.

Forty to 60% of all primary (arising in the heart) heart tumors are myxomas. Most myxomas occur in the left atrium, the chamber of the heart that receives oxygen-rich blood from the lungs. Myxomas usually develop in women, typically between the ages of 40 and 60 years.

Some uncommon types of myxomas run in families. These hereditary myxomas (part of Carney complex, a syndrome of various noncancerous tumors) usually develop in people in their mid-20s, and they can occur in one or more of any of the chambers of the heart.

How a Myxoma Can Block Blood Flow in the Heart

A myxoma in the left atrium often grows from a stalk and swings freely with the flow of blood. As it swings, the myxoma may move in and out of the nearby mitral valve, which opens from the left atrium into the left ventricle. This swinging motion may plug and unplug the valve over and over again, so that blood flow stops and starts intermittently.

Myxomas in the left atrium often grow from a stalk and swing freely with the flow of blood, as a tetherball does. As they swing, they may move in and out of the nearby mitral valve, the valve that opens from the left atrium into the left ventricle. This swinging motion may plug and unplug the valve over and over again, so that blood flow stops and starts intermittently.

Symptoms of Myxomas

When they stand, people with a myxoma in the left atrium may feel short of breath or may faint. When a person is standing, the force of gravity pulls the myxoma into the opening of the mitral valve, blocking blood flow through the heart. This blockage causes a transient drop in blood pressure because less blood is able to be pumped from the heart. Lying down typically causes the myxoma to move away from the valve and relieves the symptoms.

Other symptoms of myxomas can include

  • Fever

  • Weight loss

  • Joint pain

  • Raynaud syndrome (the fingers and toes become cold and painful when exposed to cold)

Complications of myxoma

Pieces of a myxoma or blood clots that form on the surface of the myxoma may break off (becoming emboli), travel through the bloodstream to other organs, and block arteries there. The resulting symptoms depend on which artery is blocked. For example, an artery in the brain blocked by tumor emboli from a left atrial myxoma may cause a stroke, and an artery in the lung blocked by emboli from a right atrial myxoma may cause pain and coughing up of blood. Emboli are the most common complication of myxomas.

Other complications include certain blood abnormalities. A low red blood cell count (anemia) can cause fatigue, weakness, and paleness. A low platelet count, can cause problems with blood clotting and people may have red, purple, or brown spots (petechiae) or bruises on their skin.

Diagnosis of Myxomas

  • A doctor's evaluation

  • Imaging

Myxomas are suspected based on the person's symptoms. With a stethoscope, doctors may hear a sound (heart murmur) produced by abnormal blood flow. The myxoma may block blood flow to or from the heart.

Because many symptoms of a myxoma may also be caused by many other disorders, extensive testing may be needed before a diagnosis is made.

Blood tests may show a high number of white blood cells (indicating inflammation), anemia, and a low number of platelets in the blood. But none of these tests is conclusive.

Doctors make the diagnosis using echocardiography. Other imaging tests, including computed tomography (CT) and magnetic resonance imaging (MRI), are sometimes necessary.

Treatment of Myxomas

  • Surgery

Surgical removal of the myxoma usually cures the person. After surgery, echocardiography is done periodically for about 5 years to be sure that the myxoma does not recur.

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