Myxoma · What Is It, Causes, Diagnosis, Treatment, and More

Clinical presentations of myxomas can vary widely depending on the location and size of the tumor.  

Cardiac myxomas often cause constitutional symptoms, such as fever, malaise, myalgia and weight loss, due to the production of interleukin-6 by the tumor. The tumors can also grow and block blood flow from the left atrium to the left ventricle through the mitral valve. This valvular obstruction can lead to a decrease in blood flow to the brain, which can cause syncopal episodes. Blockage of the flow through the mitral valve can also lead to a build-up of blood in the lungs, which can cause dyspnea and pulmonary edema, which refers to excess fluid in the lungs. If valvular obstruction occurs at the right side of the heart, the individual can experience symptoms of right heart failure. With right heart failure, the right atrium is unable to empty blood into the right ventricle, causing the blood to back up and result in congestion of the veins. This can present with visible bulging of the jugular veins in the neck (i.e., jugular vein distention), enlargement of the liver and spleen (i.e., hepatosplenomegaly), and swelling of the legs. 

In addition, small pieces of the mass can break off and travel through the bloodstream, potentially causing a blockage of an artery (i.e., embolism). If this occurs in the right side of the heart, the small pieces can travel towards the lungs and cause a pulmonary embolism, which can result in shortness of breath and chest pain. If emboli originate from the left side of the heart, they can travel to the brain or extremities and cause a stroke or arterial embolism, respectively. Both valvular obstruction and embolisms can potentially cause sudden death.  

Additionally, cardiac myxomas can interfere with the electrical signaling of the heart and cause abnormal heart rhythms, most commonly atrial arrhythmias such as atrial fibrillation. This can be felt as palpitations or the feeling of extra or skipped heartbeats. In some cases of cardiac myxomas, however, individuals can be completely asymptomatic.  

The other types of myxomas often cause less severe signs and symptoms. Intramuscular myxoma, which most commonly involves the muscles of the thighs and shoulders, can present as a painless, palpable mass, which is slightly movable. Pain or neurological symptoms due to mass effects may occur. Cutaneous myxoma can present as a nodule on the face, trunk, or extremities. Finally, conjunctival myxoma, which is a type of ocular myxoma typically presents as a slow-growing, painless, yellow-pink cyst-like mass in the conjunctiva, the membrane covering the front part of the eye. 

Diagnosis of all myxomas depends on the location and size of the tumor. Regardless, diagnosis generally begins with a medical assessment of signs and symptoms.  

In individuals experiencing symptoms associated with a cardiac myxoma, a physical examination can reveal the presence of abnormal heart sounds. Blood tests might show anemia, or a lack of red blood cells. An electrocardiogram (ECG), which measures the heart’s electrical signals, may reveal atrial fibrillation. Imaging tests that can be used to diagnose cardiac myxoma include an ultrasound of the heart (i.e., echocardiogram), chest X-rays, computerized tomography (CT) scans, or magnetic resonance imaging (MRI). An echocardiogram can be used to detect the presence and location of the tumor and evaluate its mobility. Chest X-rays might reveal cardiomegaly, calcification of the tumor, evidence of valvular obstruction, or pulmonary edema. CT and MRI scans can provide enhanced visualization of the cardiac tumor and its location within the heart.  

 Intramuscular myxomas are also often visualized using ultrasound imaging, CT scans, or MRI. They are commonly confirmed with a biopsy and pathological examination of the suspected tumor. Similarly, ocular and cutaneous myxomas are typically confirmed with a biopsy.

Myxomas can be removed through surgical intervention. Cardiac myxomas are typically removed through open heart surgery, although total endoscopic surgery is emerging as a less invasive alternative in selected cases at specialized centers. The atrial septum may also be removed during the operation, depending on the depth of tumor penetration. The pericardium, which is a two-layered membrane that covers the heart, can be used to repair the atrial septum in such cases. When the myxoma extends into the mitral valve, individuals may need to have the valve replaced. In rare instances, myxomas can recur if the tumor is not completely removed during surgery. 

Intramuscular and ocular myxomas can be also removed through surgical excision, after which recurrence of the tumor is rare. On the other hand, cutaneous myxomas frequently reform, even after surgical removal.