Also found in: Dictionary, Thesaurus, Encyclopedia, Wikipedia.
Related to myxoma: Atrial myxoma




A myxoma is a rare, usually noncancerous, primary tumor (a new growth of tissue) of the heart. It is the most common of all benign heart tumors.


Myxoma is an intracardiac tumor; it is found inside the heart. Seventy five percent of all myxomas are found in the left atrium, and almost all other myxomas are found in the right atrium. It is very rare for a myxoma to be found in either of the ventricles. The tumor takes one of two general shapes: a round, firm mass, or an irregular shaped, soft, gelatinous mass. They are attached to the endocardium, the inside lining of the heart. The cells that make up the tumor are spindle-shaped cells and are embedded in a matrix rich in mucopolysaccharides (a group of carbohydrates). Myxomas may contain calcium, which shows up on x rays. The tumor gets its blood supply from capillaries that bring blood from the heart to the tumor. Thrombi (blood clots) may be attached to the outside of the myxoma.
There are three major syndromes linked to myxomas: embolic events, obstruction of blood flow, and constitutional syndromes. Embolic events happen when fragments of the tumor, or the thrombi attached to the outside of the tumor, are released and enter the blood stream. Gelatinous myxomas are more likely to embolize than the more firm form of this tumor.
Myxomas may also obstruct blood flow in the heart, usually at a heart valve. The mitral valve is the heart valve most commonly affected. Blood flow restrictions can lead to pulmonary congestion and heart valve disease. Embolization can lead to severe consequences. In cases of left atrial myxoma, 40-50% of patients experience embolization. Emboli usually end up in the brain, kidneys, and extremities.
The third syndrome linked to myxomas are called constitutional syndromes, nonspecific symptoms caused by the myxoma.

Causes and symptoms

There is no known causative agent for myxoma. The main symptoms, if any, produced by myxoma are generic and not specific. These include fever, weight loss, anemia, elevated white blood cell (WBC) count, decreased platelet count and Raynaud's phenomenon. Most patients with myxoma are between 30-60 years of age.


Diagnosis is made following a suspicion that a myxoma might be present, and can usually be confirmed by echocardiogram


Surgery is used to remove the tumor. Myxomas can regrow if they are not completely removed. The survival rate for this operation is excellent.


Successful removal of the tumor rids the patient of this disease. Emboli from a myxoma may survive in other areas of the body. However, there is no evidence that myxoma is truly metastatic (able to transfer disease from one area to another), causing tumors in other areas of the body.

Key terms

Embolus — A piece of tissue, blood clot, etc. that travels through the blood system and can lodge in smaller blood vessels anywhere in the body.
Metastasis — The spread of a cancer or infectious agent from the site of origin to other areas of the body.
Raynaud's phenomenon — Intermittant ischemia (deficient blood flow) of the fingers or toes, sometimes also affecting the ears and nose.



"Myxoma, Intracardiac." OMIM Home Page, Online Mendelian Inheritance in Man.


a tumor composed of primitive connective tissue cells and stroma resembling mesenchyma. adj., adj myxo´matous.


A benign neoplasm derived from connective tissue, consisting chiefly of polyhedral and stellate cells that are loosely embedded in a soft mucoid matrix, thereby resembling primitive mesenchymal tissue; occurs frequently intramuscularly (where it may be mistaken for a sarcoma), also in the jaw bones, and encysted in the skin (focal mucinosis and dorsal wrist ganglion).
[myxo- + G. -ōma, tumor]


/myx·o·ma/ (mik-so´mah) pl. myxomas, myxo´mata   a benign tumor composed of primitive connective tissue cells and stroma resembling mesenchyme.


n. pl. myxo·mas or myxo·mata (-mə-tə)
A benign tumor, most often found in the heart, composed of connective tissue embedded in mucus.

myx·o′ma·tous (-sō′mə-təs, -sŏm′ə-) adj.


Etymology: Gk, myxa + oma, tumor
a neoplasm of the connective tissue, characteristically composed of stellate cells in a loose mucoid matrix crossed by delicate reticulum fibers. These tumors may grow to enormous size and may occur under the skin but are also found in bones, the genitourinary tract, and the retroperitoneal area. myxomatous, adj.


A benign neoplasm derived from connective tissue, consisting of polyhedral and stellate cells embedded in a soft mucoid matrix; occurs in bone, skin, and muscle; when arising from cardiac muscle may encroach on the cavity of an atrium.
[myxo- + G. -ōma, tumor]


A rare, benign, jelly-like tumour consisting of soft mucoid material, mainly hyaluronic acid. Myxomas may affect muscles, especially in the shoulder and thigh and sometimes occur within one of the chambers of the heart. A myxoma in this situation may cause blood clot EMBOLI or may interfere with the normal flow of blood. If necessary, a cardiac myxoma may be removed surgically.


Benign neoplasm derived from connective tissue, found intramuscularly and in jaw bones.
[myxo- + G. -ōma, tumor]

myxoma (miksō´mə),

n a benign tumor composed of fibroblastic cells that have reverted to embryonic growth and produce a mucoid matrix containing widely dispersed stellate cells that have multipolar processes. myxoma, odontogenic, n a new growth of soft tissue, gelatinous in appearance, originating from the mesenchymal tissue of the tooth. The growth may invade tissues surrounding the region, and it does not metastasize or provide any bodily function.


a tumor composed of primitive connective tissue cells and stroma resembling mesenchyme.

heart valve myxoma
developmental abnormality caused by persistence of embryonic myxomatous tissue in the endocardial cushions.
myxoma virus
a poxvirus in the genus Leporipoxvirus; the cause of myxomatosis of rabbits.
References in periodicals archive ?
A Case of odontogenic myxoma with unusual histological features mimicking a fibro-osseous process.
Symptoms from a cardiac myxoma are more pronounced when the myxomas are left-sided, racemosus, and over 5 cm in diameter [6].
In the case described here, obstruction of the mitral valve by the myxoma may have provoked syncope and features of left ventricular failure.
Based on the clinical, gross, and mainly histopathologic findings, the bird was diagnosed with myxoma.
Sudhakar S, Robinson P, Loyo J, Hai H, Sewani A An unusual case of left ventricular myxoma.
Identification of a novel genetic locus for familial cardiac myxomas and Carney complex.
Other lesions had a lower incidence, such as myxoma (3%), CCOT (3%), cementoblastoma (2%), COF (1%), and CEOT (1%).
The seriousness of the tumour - a left atrial myxoma - meant she was immediately referred to Liverpool Heart and Chest Hospital.
Other cardiac causes include valvular heart disease, prosthetic heart valves, post-myocardial infarction, ventricular aneurysm, atrial myxoma, and paradoxical embolism in a patient with a patent foramen ovale.
Of all primary cardiac tumors, benign tumors have a higher incidence, of which the most common is the atrial myxoma (4).
Current early stage melanoma treatments require minor surgery to cut out the cancer cells and healthy skin around a mole but the new research has created a peptide, or a chain of amino acids, that mimics how the proteins of the myxoma virus interact with melanoma cells.