Myxoma overview
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Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]; Associate Editor-In-Chief: Cafer Zorkun, M.D., Ph.D. [2]Ahmad Al Maradni, M.D. [3]Maria Fernanda Villarreal, M.D. [4]
Overview
A myxoma (Myxo- = Latin for mucus) is the most common primary tumor of the heart. Myxomas are usually located in either the left or right atrium of the heart; about 86 percent occur in the left atrium.[1] Myxomas are typically pedunculated, with a stalk that is attached to the interatrial septum. The most common location for attachment of the stalk is the fossa ovalis region of the interatrial septum. The phrase "myxomatous degeneration" refers to the process in which connective tissue becomes filled with mucus. About 71% of myxomas occur in the heart, 41% on the skin, and 7% in the oral cavity (usually on the palate). Common physical examination findings of myxoma include murmur and abnormal heart sounds that change when the patient changes positions. Complications that can develop as a result of myxoma are: arrhythmias, pulmonary edema, peripheral emboli, metastasis, blockage of the mitral heart valve. Surgery is the mainstay of treatment for myxomas.[2]
Historical Perspective
In 1845, the first description of a left atrial myxoma was reported by King.[3] In 1951, Prichard described a kind of microscopic endocardial structure of the atrial septum, which was suggested to be associated with cardiac myxoma.[4] Clarence Crafoord a Swedish cardiovascular surgeon, successfully removed a cardiac myxoma for the first time in 1954. This case also represented the first extirpation of a cardiac tumor on cardiopulmonary support.[5] Before 1951, cardiac myxoma diagnosis was made only at autopsy. In 1959, the first M-mode echocardiogram of a left atrial myxoma was reported.[6]
Classification
Cardiac myxomas are classified by the WHO histological classification of tumors of the heart "Benign tumors and tumor-like lesions" and categorized into a type of pluripotent mesenchymal tumor.[7][8]
Pathophysiology
Cardiac myxoma arises from remnants of subendocardial vasoformative reserve cells, which are primitive mesenchymal cells that are normally involved in the supportive structure of the endocardium.[9][10] Myxomas are usually located in the fossa ovalis and endocardium of the atrial septum
Some symptoms of myxoma may be associated with the release of interleukin 6 (IL-6).[11][12] On gross pathology, a gelatinous, irregular surface that fills the left atrium is characteristic finding of myxoma. A common hystopathological finding is the Gamna-Gandy Bodies that consist of fibrosis and deposition of iron pigments.
Causes
About 10% of cardiac myxomas are passed down through families (inherited). Right atrial myxomas are sometimes associated with tricuspid stenosis and atrial fibrillation, however the underlying mechanism remains unknown.[13]
Differentiating Myxoma from other Diseases
Cardiac myxoma should be differentiated from other cardiac tumor including lipoma, rhabdomyoma, rhabdomyosarcoma, thrombosis and metastasis.
Epidemiology and Demographics
Cardiac myxomas are the most common primary cardiac tumor in adults, but are relatively infrequent in childhood. There is a wide range in the age of presentation (11-82 years), with most patients presenting in adulthood (mean ~50 years of age). There is a recognized female predilection.[14][15] The incidence of benign cardiac tumor including myxoma is about 250 per 100,000 persons.[16]
Risk Factors
Common risk factors in the development of cardiac myxoma are female gender and genetic predisposition.[17]
Natural History, Complications and Prognosis
If left untreated, cardiac myxoma progression occurs slowly. The overlapping of various phenomena such as thrombosis, hemorrhage, or fragmentation may influence tumor growth, detachment, and consequently embolism.[18] Constitutional symptoms, such as: weight loss, fatigue, weakness are often the initial clinical onset of cardiac myxoma, and may resemble those from endocarditis. Metastases are very uncommon in cardiac myxoma.
Since the majority of the cardiac myxomas are left sided, it may progress to develop mitral valve obstruction or systemic embolic events, such as stroke. Whereas, right atrial myxomas may obstruct the tricuspid valve and can present as right sided heart failure. Approximately 20% of patients with cardiac myxoma are asymptomatic. Overall, clinical features of cardiac myxoma are associated with the size of the tumor, location, size and mobility.[19]
Diagnosis
Staging
There is no established system for the staging of myxoma.[20]
History and Symptoms
Symptoms associated with cardiac myxomas are typically due to the effect of the mass of the tumor obstructing the normal blood flow within the heart chambers. Left atrial myxoma symptoms may mimic mitral stenosis, while right atrial myxomas rarely produce symptoms until they have grown to be at least 13 cm wide. [21] General symptoms may also mimic those of infective endocarditis.[22] Cardiac myxoma symptoms may occur at any time, but most often they tend to occur with changes in body position. Common symptoms include: chest pain, palpitation, dizziness, syncope and dyspnea on exertion.
Physical Examination
There are no specific physical findings for cardiac myxoma.[23][24][25]The physical sign that may be remarkable for cardiac myxoma is the "tumor plop" which is caused by the obstruction of the mitral valve orifice by the tumor.[24] Common findings include systolic or diastolic murmurs (depending on size, mobility and location of the tumor). Normally, diastolic murmurs are due to the obstruction of the left/right ventricle. Whereas systolic murmurs are related to the narrow closure of the atrioventricular valves. Another finding is abnormal heart sounds that change when the patient changes positions. For instance, in patients with left atrial myxomas, S1 is often loud and widely split, because the tumor has caused a delay in the closure of the mitral valve. In most cases, a common ascultatory finding is the accentuated first heart sound and the loud pulmonary component of the second heart sound.
Laboratory Findings
Laboratory findings consistent with cardiac myxoma show anemia, leukocytosis and elevated erythrocyte sedimentation rate.
Chest X-ray
On chest x-ray, cardiac myxomas are characterized by normal findings and in some cases a calcification overlying the posterior aspect of heart.
CT Scan
On myxoma CT scan is characterised by low attenuation and areas of dystrophic calcification in cardiac chambers.
MRI
Findings on MRI of cardiac myxoma include heterogenous appearence, non-uniformity of the masses, spherical or ovoid masses (sessile or pedunculated)[26]
Echocardiography
The echocardiogram is the initial modality and most useful diagnostic imaging study in cardiac myxoma. On cardiac ultrasound, cardiac myxoma is characterised by the presence of a heterogeneous pedunculated mass that is commonly located in the left atrium. Echocardiography allows for evaluation assessment of tumor mobility, as it often protrudes through valve flaps. As a test modality, two-dimensional echocardiography is often coupled with other modalities (such as, Doppler echocardiography) to detect vascular abnormalities that frequently occur in cardiac myxomas. [27]
Other Diagnostic Studies
Additional tests recommended for the diagnosis of cardiac myxoma include: cardiac angiography.
Treatment
Medical Therapy
There is no known medical therapy for Myxomas.
Surgery
Surgery is the mainstay of treatment for myxomas.
References
- ↑ Knepper LE, Biller J, Adams HP Jr, Bruno A. Neurologic manifestations of atrial myxoma. A 12-year experience and review. Stroke. 1988 Nov;19(11):1435-40. (Medline abstract)
- ↑ Cardiac Myxoma. Radiopedia. http://radiopaedia.org/articles/cardiac-myxoma Accessed on November 30,2015
- ↑ King TW. On simple vascular growths in the left auricle of the heart. Lancet 1845; 2:428-9
- ↑ Amano J, Kono T, Wada Y, Zhang T, Koide N, Fujimori M, Ito K (2003). "Cardiac myxoma: its origin and tumor characteristics". Ann Thorac Cardiovasc Surg. 9 (4): 215–21. PMID 13129418.
- ↑ Chitwood WR (1992). "Clarence Crafoord and the first successful resection of a cardiac myxoma". Ann. Thorac. Surg. 54 (5): 997–8. PMID 1417305.
- ↑ Pinede L, Duhaut P, Loire R (2001). "Clinical presentation of left atrial cardiac myxoma. A series of 112 consecutive cases". Medicine (Baltimore). 80 (3): 159–72. PMID 11388092.
- ↑ Amano J, Nakayama J, Yoshimura Y, Ikeda U (2013). "Clinical classification of cardiovascular tumors and tumor-like lesions, and its incidences". Gen Thorac Cardiovasc Surg. 61 (8): 435–47. doi:10.1007/s11748-013-0214-8. PMC 3732772. PMID 23460447.
- ↑ Wold LE, Lie JT (1980). "Cardiac myxomas: a clinicopathologic profile". Am. J. Pathol. 101 (1): 219–40. PMC 1903582. PMID 7446701.
- ↑ Roscher AA, Kato NS, Quan H, Padmanabhan M (1996). "Intra-atrial myxomas, clinical-pathologic correlation based on two case studies including historical review". J Cardiovasc Surg (Torino). 37 (6 Suppl 1): 131–7. PMID 10064365.
- ↑ Acebo E, Val-Bernal JF, Gómez-Román JJ (2001). "Prichard's structures of the fossa ovalis are not histogenetically related to cardiac myxoma". Histopathology. 39 (5): 529–35. PMID 11737312.
- ↑ Seino Y, Ikeda U, Shimada K. (1993). "Increased expression of interleukin 6 mRNA in cardiac myxomas". Br Heart J. 69 (6): 565–7. PMID 8343326.
- ↑ Jourdan M, Bataille R, Seguin J, Zhang XG, Chaptal PA, Klein B (1990). "Constitutive production of interleukin-6 and immunologic features in cardiac myxomas". Arthritis Rheum. 33 (3): 398–402. PMID 1690543.
- ↑ Atrial Myxoma.Wikipedia URL https://en.wikipedia.org/wiki/Atrial_myxoma Accessed November 13, 2015
- ↑ Cardiac Myxoma. Radiopedia URL http://radiopaedia.org/articles/cardiac-myxoma Accessed on November 13,2015
- ↑ Yoon DH, Roberts W (2002). "Sex distribution in cardiac myxomas". Am. J. Cardiol. 90 (5): 563–5. PMID 12208428.
- ↑ National Cancer Institute. Physician Data Query Database 2015. http://www.cancer.gov/publications/pdp
- ↑ Atrial myxoma. Wikipedia https://en.wikipedia.org/wiki/Atrial_myxoma Accessed November 13, 2015
- ↑ Markel ML, Waller BF, Armstrong WF (1987). "Cardiac myxoma. A review". Medicine (Baltimore). 66 (2): 114–25. PMID 3547010.
- ↑ Burke A, Virmani R. Tumors of the Heart and Great Vessels. Amer Registry of Pathology; 1996.
- ↑ Atrial myxoma. Wikipedia https://en.wikipedia.org/wiki/Atrial_myxoma Accessed November 13, 2015
- ↑ Ramchandani M (2010). "Less invasive surgery for cardiac tumors". Methodist Debakey Cardiovasc J. 6 (3): 27–31. PMID 20834208.
- ↑ Atrial myxoma. Wikipedia https://en.wikipedia.org/wiki/Atrial_myxoma Accessed November 13, 2015
- ↑ Bulkley BH, Hutchins GM (1979). "Atrial myxomas: a fifty year review". Am. Heart J. 97 (5): 639–43. PMID 433739.
- ↑ 24.0 24.1 Goswami KC, Shrivastava S, Bahl VK, Saxena A, Manchanda SC, Wasir HS (1998). "Cardiac myxomas: clinical and echocardiographic profile". Int. J. Cardiol. 63 (3): 251–9. PMID 9578352.
- ↑ Grebenc ML, Rosado-de-Christenson ML, Green CE, Burke AP, Galvin JR (2002). "Cardiac myxoma: imaging features in 83 patients". Radiographics. 22 (3): 673–89. doi:10.1148/radiographics.22.3.g02ma02673. PMID 12006696.
- ↑ Myxoma.Radiopedia.http://radiopaedia.org/articles/cardiac-myxoma Accessed on November 13, 2015
- ↑ Bentivoglio M, Savino K, Corea L, Verdecchia P, Porcellati C (1989). "[Doppler echocardiography in atrial myxoma]". Cardiologia (in Italian). 34 (9): 783–6. PMID 2605587.