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{{Myxoma}}
{{Myxoma}}
{{CMG}}; '''Associate Editor-In-Chief:'''  {{CZ}}{{AAM}}{{MV}}
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==Overview==
==Overview==
A '''myxoma''' (''Myxo-'' = Latin for [[mucus]]) is the most common primary [[tumor]] of the [[heart]]. Myxomas are usually located in either the [[left atrium|left]] or [[right atrium]] of the heart; about 86 percent occur in the [[left atrium]].<ref>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. ([http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=3188128 Medline abstract])</ref>
A '''myxoma''' (''Myxo-'' = Latin for [[mucus]]) is the most common primary [[tumor]] of the [[heart]]. Cardiac myxoma was first described in 1845. In 1951, Prichard described a kind of microscopic [[endocardial]] structure of the [[atrial]] [[septum]], which was suggested to be associated with cardiac myxoma. Clarence Crafoord, a Swedish cardiovascular surgeon successfully removed a [[cardiac]] myxoma for the first time in 1954. Before 1951, cardiac myxoma diagnosis was made only at [[post-mortem]] examination. In 1959, the first [[M-mode echo: principles and classic findings|M-mode]] [[echocardiogram]] of a left atrial myxoma was reported. 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. 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]]. 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). On [[gross pathology]], a gelatinous, irregular surface that fills the [[left atrium]] is the characteristic finding of myxoma. A common [[histopathological]] finding is the ''Gamna-Gandy Bodies'' that consist of fibrosis and deposition of [[pigments|iron pigments]]. The main cause of cardiac myxoma remains unknown. However, in some cases like inherited myxomatosis, there is a strong relation with genetic mutations of PRKAR1A gene. Cardiac myxoma should be differentiated from other benign and malignant primary heart tumors including [[papillary fibroelastoma]], [[lipoma]], [[rhabdomyoma]], and cardiac [[metastasis]]. Cardiac myxomas are the most common primary cardiac tumor in adults, with a reported prevalence of 0.03% in general [[population]]. The [[incidence]] of cardiac myxoma is about 1/ 100,000 per year. The majority of patients with cardiac myxoma are diagnosed between 30 to 60 years; children are rarely affected. Females are more commonly affected with cardiac myxoma than men. The female-to-male ratio is approximately 1.8 to 1. Cardiac myxomas represent 78% of heart tumors. Common risk factors in the development of myxoma are female gender and genetic predisposition. In some cases, right atrial myxoma has been associated with [[tricuspid stenosis]] and [[atrial fibrillation]]. If left untreated, cardiac myxoma progression occurs slowly. The overlap of various phenomena such as [[thrombosis]], [[hemorrhage]], or fragmentation may influence tumor growth, detachment, and consequently [[embolism]]. 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 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. There is no single diagnostic study of choice for myxoma. Myxoma may be diagnosed based on clinical presentation and detecting the cardiac mass. 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. General [[symptoms]] may also mimic those of [[infective endocarditis]]. 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]]. There are no specific physical findings for cardiac myxoma. The auscultatory presence of a "tumor plop" (which is caused by the obstruction of the mitral valve orifice by the tumor) on physical examination is highly suggestive of cardiac myxoma. Common physical examination findings of cardiac myxoma include [[systolic]] or [[diastolic murmurs]] (depending on size, mobility, and location of the tumor). Laboratory findings consistent with cardiac myxoma are generally non-specific, results often demonstrate [[anemia]], [[leukocytosis]] and elevated [[erythrocyte sedimentation rate]]. On [[chest x-ray]], cardiac myxoma is characterized by normal results and in some cases a [[calcification]] overlying the heart. On [[CT scan]], cardiac myxoma is characterized by low attenuation and areas of [[dystrophic calcification]] in cardiac chambers. CT scan may be helpful in the diagnosis of cardiac myxoma because it provides better soft-tissue contrast than echocardiography, and it can also differentiate calcification and fat, and may allow tissue diagnosis of some masses such as [[Lipoma|lipomas]]. On Magnetic Resonance Imaging (MRI) or [[CMR|Cardiac Magnetic Resonance (CMR)]], cardiac myxoma is characterized by a [[soft tissue]] mass within the [[cardiac chambers]] isointense to [[skeletal muscle]]. This imaging modality plays an important role in the evaluation of cardiac masses and is of great value when [[echocardiographic]] findings are suboptimal or when the lesion has an atypical location or appearance. The [[echocardiogram]] is the initial modality and most useful diagnostic imaging study in cardiac myxoma. On cardiac [[ultrasound]], cardiac myxoma is characterized 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 testing modality, [[two-dimensional echocardiography]] is often coupled with other modalities (such as, [[Doppler echocardiography]]) to detect vascular abnormalities that frequently occur in cardiac myxomas. Another diagnostic study for cardiac myxoma is [[Angiography|cardiac angiography]], which often demonstrates contrast media-enhanced tumor vasculature. There is no known medical therapy for cardiac myxomas. Surgery is the mainstay of treatment for cardiac myxoma. The feasibility of surgery depends on the patient hemodynamic stability at diagnosis. Cardiac myxoma surgery has operative mortality around 0 to 3%, depending on risk factors or mechanical damage to a heart valve, as well as adhesion of the tumor to valve leaflets. The short and long-term prognosis is generally regarded as excellent.
Myxomas are typically [[peduncle (anatomy)|pedunculate]]d, 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.<ref> Cardiac Myxoma. Radiopedia. http://radiopaedia.org/articles/cardiac-myxoma Accessed on November 30,2015</ref>
 
==Historical Perspective==
==Historical Perspective==


In 1845, the first description of a left atrial myxoma was reported by King.<ref> King TW. On simple vascular growths in the left auricle of the heart. Lancet 1845; 2:428-9</ref> In 1951, Prichard described a kind of microscopic endocardial structure of the [[atrial septum]], which was suggested to be associated with cardiac myxoma.<ref name|overview="pmid13129418">{{cite journal |vauthors=Amano J, Kono T, Wada Y, Zhang T, Koide N, Fujimori M, Ito K |title=Cardiac myxoma: its origin and tumor characteristics |journal=Ann Thorac Cardiovasc Surg |volume=9 |issue=4 |pages=215–21 |year=2003 |pmid=13129418 |doi= |url=}}</ref> 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.<ref name="pmid1417305">{{cite journal |vauthors=Chitwood WR |title=Clarence Crafoord and the first successful resection of a cardiac myxoma |journal=Ann. Thorac. Surg. |volume=54 |issue=5 |pages=997–8 |year=1992 |pmid=1417305 |doi= |url=}}</ref> Before 1951, cardiac myxoma diagnosis was made only at [[autopsy]]. In 1959, the first M-mode [[echocardiogram]] of a left atrial myxoma was reported.<ref name="pmid11388092">{{cite journal |vauthors=Pinede L, Duhaut P, Loire R |title=Clinical presentation of left atrial cardiac myxoma. A series of 112 consecutive cases |journal=Medicine (Baltimore) |volume=80 |issue=3 |pages=159–72 |year=2001 |pmid=11388092 |doi= |url=}}</ref>
Cardiac myxoma was first described in 1845. In 1951, Prichard described a kind of microscopic [[endocardial]] structure of the [[atrial septum]], which was suggested to be associated with cardiac myxoma. Clarence Crafoord, a Swedish cardiovascular surgeon successfully removed a cardiac myxoma for the first time in 1954. Before 1951, cardiac myxoma diagnosis was made only at [[post-mortem]] examination. In 1959, the first M-mode [[echocardiogram]] of a left atrial myxoma was reported.


==Classification==
==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.<ref name="pmid23460447">{{cite journal |vauthors=Amano J, Nakayama J, Yoshimura Y, Ikeda U |title=Clinical classification of cardiovascular tumors and tumor-like lesions, and its incidences |journal=Gen Thorac Cardiovasc Surg |volume=61 |issue=8 |pages=435–47 |year=2013 |pmid=23460447 |pmc=3732772 |doi=10.1007/s11748-013-0214-8 |url=}}</ref><ref name="pmid7446701">{{cite journal |vauthors=Wold LE, Lie JT |title=Cardiac myxomas: a clinicopathologic profile |journal=Am. J. Pathol. |volume=101 |issue=1 |pages=219–40 |year=1980 |pmid=7446701 |pmc=1903582 |doi= |url=}}</ref>
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.


==Pathophysiology==
==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]].<ref name="pmid10064365">{{cite journal |vauthors=Roscher AA, Kato NS, Quan H, Padmanabhan M |title=Intra-atrial myxomas, clinical-pathologic correlation based on two case studies including historical review |journal=J Cardiovasc Surg (Torino) |volume=37 |issue=6 Suppl 1 |pages=131–7 |year=1996 |pmid=10064365 |doi= |url=}}</ref><ref name="pmid11737312">{{cite journal |vauthors=Acebo E, Val-Bernal JF, Gómez-Román JJ |title=Prichard's structures of the fossa ovalis are not histogenetically related to cardiac myxoma |journal=Histopathology |volume=39 |issue=5 |pages=529–35 |year=2001 |pmid=11737312 |doi= |url=}}</ref> Myxomas are usually located in the [[fossa ovalis]] and [[endocardium]] of the [[atrial septum]]
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]]. 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).<ref name="Seino-IL6">{{cite journal | author=Seino Y, Ikeda U, Shimada K. | title=Increased expression of interleukin 6 mRNA in cardiac myxomas. | journal=Br Heart J | year=1993 | volume=69 | issue=6 | pages=565-7 | id=PMID 8343326}}</ref><ref name="Jourdan-IL6">{{cite journal | author=Jourdan M, Bataille R, Seguin J, Zhang XG, Chaptal PA, Klein B | title=Constitutive production of interleukin-6 and immunologic features in cardiac myxomas.| journal=Arthritis Rheum | year=1990 | volume=33 | issue=3 | pages=398-402 | id=PMID 1690543}}</ref> 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 [[pigments|iron pigments]].
Some symptoms of myxoma may be associated with the release of [[interleukin 6]] (IL-6). On [[gross pathology]], a gelatinous, irregular surface that fills the [[left atrium]] is the characteristic finding of myxoma. A common [[histopathological]] finding is the ''Gamna-Gandy Bodies'' that consist of fibrosis and deposition of [[pigments|iron pigments]].


==Causes==
==Causes==
 
The main cause of cardiac myxoma remains unknown. However, in some cases like inherited myxomatosis, there is a strong relation with genetic mutations of PRKAR1A gene.
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.<ref> Atrial Myxoma.Wikipedia URL https://en.wikipedia.org/wiki/Atrial_myxoma Accessed November 13, 2015</ref>


==Differentiating Myxoma from other Diseases==
==Differentiating Myxoma from other Diseases==
Cardiac myxoma should be differentiated from other cardiac tumor including [[lipoma]], [[rhabdomyoma]], [[rhabdomyosarcoma]], [[thrombosis]] and [[ metastasis]].
Cardiac myxoma should be differentiated from other benign and malignant primary heart tumors including [[papillary fibroelastoma]], [[lipoma]], [[rhabdomyoma]], and cardiac [[metastasis]].


==Epidemiology and Demographics==
==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.<ref>Cardiac Myxoma. Radiopedia URL http://radiopaedia.org/articles/cardiac-myxoma Accessed on November 13,2015 </ref><ref name="pmid12208428">{{cite journal |vauthors=Yoon DH, Roberts W |title=Sex distribution in cardiac myxomas |journal=Am. J. Cardiol. |volume=90 |issue=5 |pages=563–5 |year=2002 |pmid=12208428 |doi= |url=}}</ref> The [[incidence]] of benign cardiac tumor including myxoma is about 250 per 100,000 persons.<ref name="cancergov">National Cancer Institute. Physician Data Query Database 2015. http://www.cancer.gov/publications/pdp</ref>
Cardiac myxomas are the most common primary cardiac tumor in adults, with a reported prevalence of 0.03% in general [[population]]. The [[incidence]] of cardiac myxoma is about 1/ 100,000 per year. The majority of patients with cardiac myxoma are diagnosed between 30 to 60 years; children are rarely affected. Females are more commonly affected with cardiac myxoma than men. The female-to-male ratio is approximately 1.8 to 1. Cardiac myxomas represent 78% of heart tumors.


==Risk Factors==
==Risk Factors==
Common risk factors in the development of cardiac myxoma are female gender and genetic predisposition.<ref> Atrial myxoma. Wikipedia https://en.wikipedia.org/wiki/Atrial_myxoma Accessed November 13, 2015 </ref>
 
Common risk factors in the development of myxoma are female gender and genetic predisposition. In some cases, right atrial myxoma has been associated with [[tricuspid stenosis]] and [[atrial fibrillation]].


==Natural History, Complications and Prognosis==
==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]].<ref name="pmid3547010">{{cite journal |vauthors=Markel ML, Waller BF, Armstrong WF |title=Cardiac myxoma. A review |journal=Medicine (Baltimore) |volume=66 |issue=2 |pages=114–25 |year=1987 |pmid=3547010 |doi= |url=}}</ref> 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.
If left untreated, cardiac myxoma progression occurs slowly. The overlap of various phenomena such as [[thrombosis]], [[hemorrhage]], or fragmentation may influence tumor growth, detachment, and consequently [[embolism]]. 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 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.<ref>Burke A, Virmani R. Tumors of the Heart and Great Vessels. Amer Registry of Pathology; 1996.</ref>
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.


==Diagnosis==
==Diagnosis==
===Staging===
 
There is no established system for the staging of myxoma.<ref> Atrial myxoma. Wikipedia https://en.wikipedia.org/wiki/Atrial_myxoma Accessed November 13, 2015 </ref>
===Diagnostic Study of Choice===
 
There is no single diagnostic study of choice for myxoma. Myxoma may be diagnosed based on clinical presentation and detecting the cardiac mass.


===History and Symptoms===
===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. <ref name="pmid20834208">{{cite journal |vauthors=Ramchandani M |title=Less invasive surgery for cardiac tumors |journal=Methodist Debakey Cardiovasc J |volume=6 |issue=3 |pages=27–31 |year=2010 |pmid=20834208 |doi= |url=}}</ref> General symptoms may also mimic those of [[infective endocarditis]].<ref> Atrial myxoma. Wikipedia https://en.wikipedia.org/wiki/Atrial_myxoma Accessed November 13, 2015 </ref> 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]].
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. General symptoms may also mimic those of [[infective endocarditis]]. 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===
===Physical Examination===
Common [[physical examination]] findings of myxoma include murmur and abnormal heart sounds that change when the patient changes positions.
 
There are no specific physical findings for cardiac myxoma. The auscultatory presence of a "tumor plop" (which is caused by the obstruction of the mitral valve orifice by the tumor) on physical examination is highly suggestive of cardiac myxoma. Common physical examination findings of cardiac myxoma include [[systolic]] or [[diastolic murmurs]] (depending on size, mobility, and location of the tumor).
 
===Laboratory Findings===
===Laboratory Findings===
Laboratory findings consistent with Myxoma show [[anemia]], [[leukocytosis]] and elevated [[erythrocyte sedimentation rate]].
 
Laboratory findings consistent with cardiac myxoma are generally non-specific, results often demonstrate [[anemia]], [[leukocytosis]] and elevated [[erythrocyte sedimentation rate]].
 
===Chest X-ray===
===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.
 
On [[chest x-ray]], cardiac myxoma is characterized by normal results and in some cases a [[calcification]] overlying the heart.


===CT Scan===
===CT Scan===
On myxoma CT scan is characterised by low attenuation and areas of [[dystrophic calcification]] in cardiac chambers.
 
On CT scan, cardiac myxoma is characterized by low attenuation and areas of [[dystrophic calcification]] in cardiac chambers. CT scan may be helpful in the diagnosis of cardiac myxoma because it provides better soft-tissue contrast than echocardiography, and it can also differentiate calcification and fat, and may allow tissue diagnosis of some masses such as lipomas.
 
===MRI===
===MRI===


Findings on MRI of cardiac myxoma include heterogenous appearence, non-uniformity of the masses, spherical or ovoid masses (sessile or pedunculated)<ref>Myxoma.Radiopedia.http://radiopaedia.org/articles/cardiac-myxoma Accessed on November 13, 2015</ref>
On Magnetic Resonance Imaging (MRI) or [[CMR|Cardiac Magnetic Resonance (CMR)]], cardiac myxoma is characterized by a [[soft tissue]] mass within the [[cardiac chambers]] isointense to [[skeletal muscle]]. This imaging modality plays an important role in the evaluation of cardiac masses and is of great value when [[echocardiographic]] findings are suboptimal or when the lesion has an atypical location or appearance.


===Echocardiography===
===Echocardiography===


 
The [[echocardiogram]] is the initial modality and most useful diagnostic imaging study in cardiac myxoma. On cardiac [[ultrasound]], cardiac myxoma is characterized 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 testing modality, [[two-dimensional echocardiography]] is often coupled with other modalities (such as, Doppler echocardiography) to detect vascular abnormalities that frequently occur in cardiac myxomas.
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. <ref name="pmid2605587">{{cite journal |vauthors=Bentivoglio M, Savino K, Corea L, Verdecchia P, Porcellati C |title=[Doppler echocardiography in atrial myxoma] |language=Italian |journal=Cardiologia |volume=34 |issue=9 |pages=783–6 |year=1989 |pmid=2605587 |doi= |url=}}</ref>


===Other Diagnostic Studies===
===Other Diagnostic Studies===


Additional tests recommended for the diagnosis of cardiac myxoma include: cardiac angiography.
Another diagnostic study for cardiac myxoma is cardiac angiography, which often demonstrates contrast media-enhanced tumor vasculature.


==Treatment==
==Treatment==
===Medical Therapy===
===Medical Therapy===


There is no known medical therapy for Myxomas.
There is no known medical therapy for cardiac myxomas.


===Surgery===
===Surgery===
Surgery is the mainstay of treatment for myxomas.
Surgery is the mainstay of treatment for cardiac myxoma. The feasibility of surgery depends on the patient hemodynamic stability at diagnosis. Cardiac myxoma surgery has operative mortality around 0 to 3%, depending on risk factors or mechanical damage to a heart valve, as well as adhesion of the tumor to valve leaflets. The short and long-term prognosis is generally regarded as excellent.


==References==
==References==
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Latest revision as of 17:21, 11 May 2020

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Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]; Associate Editor(s)-in-Chief: Sogand Goudarzi, MD [2]Maria Fernanda Villarreal, M.D. [3]Cafer Zorkun, M.D., Ph.D. [4]Ahmad Al Maradni, M.D. [5]

Overview

A myxoma (Myxo- = Latin for mucus) is the most common primary tumor of the heart. Cardiac myxoma was first described in 1845. In 1951, Prichard described a kind of microscopic endocardial structure of the atrial septum, which was suggested to be associated with cardiac myxoma. Clarence Crafoord, a Swedish cardiovascular surgeon successfully removed a cardiac myxoma for the first time in 1954. Before 1951, cardiac myxoma diagnosis was made only at post-mortem examination. In 1959, the first M-mode echocardiogram of a left atrial myxoma was reported. 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. 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. 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). On gross pathology, a gelatinous, irregular surface that fills the left atrium is the characteristic finding of myxoma. A common histopathological finding is the Gamna-Gandy Bodies that consist of fibrosis and deposition of iron pigments. The main cause of cardiac myxoma remains unknown. However, in some cases like inherited myxomatosis, there is a strong relation with genetic mutations of PRKAR1A gene. Cardiac myxoma should be differentiated from other benign and malignant primary heart tumors including papillary fibroelastoma, lipoma, rhabdomyoma, and cardiac metastasis. Cardiac myxomas are the most common primary cardiac tumor in adults, with a reported prevalence of 0.03% in general population. The incidence of cardiac myxoma is about 1/ 100,000 per year. The majority of patients with cardiac myxoma are diagnosed between 30 to 60 years; children are rarely affected. Females are more commonly affected with cardiac myxoma than men. The female-to-male ratio is approximately 1.8 to 1. Cardiac myxomas represent 78% of heart tumors. Common risk factors in the development of myxoma are female gender and genetic predisposition. In some cases, right atrial myxoma has been associated with tricuspid stenosis and atrial fibrillation. If left untreated, cardiac myxoma progression occurs slowly. The overlap of various phenomena such as thrombosis, hemorrhage, or fragmentation may influence tumor growth, detachment, and consequently embolism. 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 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. There is no single diagnostic study of choice for myxoma. Myxoma may be diagnosed based on clinical presentation and detecting the cardiac mass. 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. General symptoms may also mimic those of infective endocarditis. 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. There are no specific physical findings for cardiac myxoma. The auscultatory presence of a "tumor plop" (which is caused by the obstruction of the mitral valve orifice by the tumor) on physical examination is highly suggestive of cardiac myxoma. Common physical examination findings of cardiac myxoma include systolic or diastolic murmurs (depending on size, mobility, and location of the tumor). Laboratory findings consistent with cardiac myxoma are generally non-specific, results often demonstrate anemia, leukocytosis and elevated erythrocyte sedimentation rate. On chest x-ray, cardiac myxoma is characterized by normal results and in some cases a calcification overlying the heart. On CT scan, cardiac myxoma is characterized by low attenuation and areas of dystrophic calcification in cardiac chambers. CT scan may be helpful in the diagnosis of cardiac myxoma because it provides better soft-tissue contrast than echocardiography, and it can also differentiate calcification and fat, and may allow tissue diagnosis of some masses such as lipomas. On Magnetic Resonance Imaging (MRI) or Cardiac Magnetic Resonance (CMR), cardiac myxoma is characterized by a soft tissue mass within the cardiac chambers isointense to skeletal muscle. This imaging modality plays an important role in the evaluation of cardiac masses and is of great value when echocardiographic findings are suboptimal or when the lesion has an atypical location or appearance. The echocardiogram is the initial modality and most useful diagnostic imaging study in cardiac myxoma. On cardiac ultrasound, cardiac myxoma is characterized 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 testing modality, two-dimensional echocardiography is often coupled with other modalities (such as, Doppler echocardiography) to detect vascular abnormalities that frequently occur in cardiac myxomas. Another diagnostic study for cardiac myxoma is cardiac angiography, which often demonstrates contrast media-enhanced tumor vasculature. There is no known medical therapy for cardiac myxomas. Surgery is the mainstay of treatment for cardiac myxoma. The feasibility of surgery depends on the patient hemodynamic stability at diagnosis. Cardiac myxoma surgery has operative mortality around 0 to 3%, depending on risk factors or mechanical damage to a heart valve, as well as adhesion of the tumor to valve leaflets. The short and long-term prognosis is generally regarded as excellent.

Historical Perspective

Cardiac myxoma was first described in 1845. In 1951, Prichard described a kind of microscopic endocardial structure of the atrial septum, which was suggested to be associated with cardiac myxoma. Clarence Crafoord, a Swedish cardiovascular surgeon successfully removed a cardiac myxoma for the first time in 1954. Before 1951, cardiac myxoma diagnosis was made only at post-mortem examination. In 1959, the first M-mode echocardiogram of a left atrial myxoma was reported.

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.

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. 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). On gross pathology, a gelatinous, irregular surface that fills the left atrium is the characteristic finding of myxoma. A common histopathological finding is the Gamna-Gandy Bodies that consist of fibrosis and deposition of iron pigments.

Causes

The main cause of cardiac myxoma remains unknown. However, in some cases like inherited myxomatosis, there is a strong relation with genetic mutations of PRKAR1A gene.

Differentiating Myxoma from other Diseases

Cardiac myxoma should be differentiated from other benign and malignant primary heart tumors including papillary fibroelastoma, lipoma, rhabdomyoma, and cardiac metastasis.

Epidemiology and Demographics

Cardiac myxomas are the most common primary cardiac tumor in adults, with a reported prevalence of 0.03% in general population. The incidence of cardiac myxoma is about 1/ 100,000 per year. The majority of patients with cardiac myxoma are diagnosed between 30 to 60 years; children are rarely affected. Females are more commonly affected with cardiac myxoma than men. The female-to-male ratio is approximately 1.8 to 1. Cardiac myxomas represent 78% of heart tumors.

Risk Factors

Common risk factors in the development of myxoma are female gender and genetic predisposition. In some cases, right atrial myxoma has been associated with tricuspid stenosis and atrial fibrillation.

Natural History, Complications and Prognosis

If left untreated, cardiac myxoma progression occurs slowly. The overlap of various phenomena such as thrombosis, hemorrhage, or fragmentation may influence tumor growth, detachment, and consequently embolism. 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 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.

Diagnosis

Diagnostic Study of Choice

There is no single diagnostic study of choice for myxoma. Myxoma may be diagnosed based on clinical presentation and detecting the cardiac mass.

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. General symptoms may also mimic those of infective endocarditis. 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. The auscultatory presence of a "tumor plop" (which is caused by the obstruction of the mitral valve orifice by the tumor) on physical examination is highly suggestive of cardiac myxoma. Common physical examination findings of cardiac myxoma include systolic or diastolic murmurs (depending on size, mobility, and location of the tumor).

Laboratory Findings

Laboratory findings consistent with cardiac myxoma are generally non-specific, results often demonstrate anemia, leukocytosis and elevated erythrocyte sedimentation rate.

Chest X-ray

On chest x-ray, cardiac myxoma is characterized by normal results and in some cases a calcification overlying the heart.

CT Scan

On CT scan, cardiac myxoma is characterized by low attenuation and areas of dystrophic calcification in cardiac chambers. CT scan may be helpful in the diagnosis of cardiac myxoma because it provides better soft-tissue contrast than echocardiography, and it can also differentiate calcification and fat, and may allow tissue diagnosis of some masses such as lipomas.

MRI

On Magnetic Resonance Imaging (MRI) or Cardiac Magnetic Resonance (CMR), cardiac myxoma is characterized by a soft tissue mass within the cardiac chambers isointense to skeletal muscle. This imaging modality plays an important role in the evaluation of cardiac masses and is of great value when echocardiographic findings are suboptimal or when the lesion has an atypical location or appearance.

Echocardiography

The echocardiogram is the initial modality and most useful diagnostic imaging study in cardiac myxoma. On cardiac ultrasound, cardiac myxoma is characterized 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 testing modality, two-dimensional echocardiography is often coupled with other modalities (such as, Doppler echocardiography) to detect vascular abnormalities that frequently occur in cardiac myxomas.

Other Diagnostic Studies

Another diagnostic study for cardiac myxoma is cardiac angiography, which often demonstrates contrast media-enhanced tumor vasculature.

Treatment

Medical Therapy

There is no known medical therapy for cardiac myxomas.

Surgery

Surgery is the mainstay of treatment for cardiac myxoma. The feasibility of surgery depends on the patient hemodynamic stability at diagnosis. Cardiac myxoma surgery has operative mortality around 0 to 3%, depending on risk factors or mechanical damage to a heart valve, as well as adhesion of the tumor to valve leaflets. The short and long-term prognosis is generally regarded as excellent.

References


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