View source for Myxoma

{{Redirect-distinguish|Myxomatous|Myxomatosis}}
{{about||the atrial subtype|Atrial myxoma|the virus|Myxoma virus}}
{{DiseaseDisorder infobox |
  Name           = Myxoma |
  ICD10          = {{ICD10|D|21|9d|10}} |
  ICD9           = {{ICD9|212.7}} |
  ICDO           = {{ICDO|8840|0}} |
  Image          = Atrial_myxoma_high_mag.jpg|
  Caption        = [[Micrograph]] of an [[atrial myxoma]]. [[H&E stain]].|
  OMIM           = 255960 |
  OMIM_mult      = |
  MedlinePlus    = |
  eMedicineSubj  = med |
  eMedicineTopic = 186 |
  DiseasesDB     = 30736 |
  MeshID         = D009232 |
}}

A '''myxoma''' (''Myxo-'' = New Latin from Greek 'muxa' for [[mucus]]) is a [[tumor]] of primitive [[connective tissue]].<ref>{{DorlandsDict|nine/000954944|Myxoma}}</ref> It is the most common primary tumor of the [[heart]] in adults, but can also occur in other locations.
The phrase "[[myxomatous degeneration]]" refers to the process in which [[connective tissue]] becomes filled with mucus. 

[[File:Myxoma_CMR.gif|thumb|right|Animated image of an [[MRI]] of the heart. ''Can you provide a better description? <span class="noprint plainlinksneverexpand">&#x5b;[{{fullurl:Myxoma|action=edit}} edit this section]&#x5d;</span>'']]
[[File:Myxoma.jpg|thumb|right|A Myxoma. A gelatinous tumor can be seen attached by a narrow pedicle to the atrial septum. The myxoma has an irregular surface and nearly fills the left atrium.]]

==Location==
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 name="pmid3188128">{{cite journal |author=Knepper LE, Biller J, Adams HP, Bruno A |title=Neurologic manifestations of atrial myxoma. A 12-year experience and review |journal=Stroke |volume=19 |issue=11 |pages=1435–40 |year=1988 |pmid=3188128 |doi=}}</ref>

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.

== Diagnosis ==
An atrial myxoma may create an extra [[Heart sounds|heart sound]], audible to [[auscultation]] just after S2.

It is most seen on [[echocardiography]], as a pedunculated mass that is heterogeneous in appearance.

A left atrial myxoma will cause an increase in [[Pulmonary wedge pressure|Pulmonary Capillary Wedge Pressure]].

The [[differential diagnosis]] include other cardiac tumors such as [[lipoma|lipomas]] and [[rhabdomyoma|rhabdomyomas]] (and rarely [[teratoma|teratomas]]).  These other tumors of the heart are typically not pedunculated, however, and are more likely to [[Infiltration (medical)|infiltrate]] the muscle of the heart. Cardiac [[magnetic resonance imaging]] (MRI) can help non-invasively diagnose cardiac tumors.  However, diagnosis usually requires examination of a [[Biopsy|tissue sample]] by a [[pathologist]].
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==Types<ref name="Review">[http://www3.interscience.wiley.com/cgi-bin/fulltext/121664953/HTMLSTART Solitary superficial angiomyxoma: an infrequent but distinct soft tissue tumor. Satter. Journal of Cutaneous Pathology, Vol 36, Issue s1, pages 56-59.]</ref>==
{| class="wikitable"
|-
!Myxoma
!Margin
!Vascular pattern
! Cellularity 
! [[Stroma (animal tissue)|Stroma]]
! [[Staining]] characteristics 
! Recurrence rate
! Image (see [[Histology]])
|-
|[[Cutaneous myxoma]] or Superficial angiomyxoma
|Poor to moderately circumscribed, multilobular 
|Scattered thin-walled vessels 
|Moderately cellular, bland spindled and [[Stellate cell|stellate cells]], variable inflammatory cell infiltrate 
|Abundant mucin with clefts. Up to 30% have an associated epithelial component 
|[[Vimentin]]; variable staining with [[CD34]], [[Factor XIII|factor XIIIA]], SMA{{ref|1|1}}, MSA{{ref|2|2}} and [[S-100 protein|S-100]]
|20–30% 
|[[Image:CutaneousMyxoma.jpg|center|100px|Cutaneous Myxoma]]
|-
|Intramuscular myxoma 
|Poorly circumscribed merges with surrounding muscle 
|Hypovascular variant; hypervascular variant 
|Hypocellular variant; hypercellular variant; bland spindle cells 
|Abundant mucin with cystic spaces. Hypercellular variant has strands of collagen 
|Vimentin; variable staining with [[actin]], [[desmin]], CD34 
|None 
|[[Image:IntramuscularMyxoma.JPG|center|100px]]
|-
|Juxta-articular myxoma 
|Poorly circumscribed infiltrates surrounding tissue 
|Focally vascular 
|Focally hypercellular, peripheral spindle cells with occasional atypical cells and mitoses 
|Abundant mucin, 89% of cases contain cystic spaces lined by fibrin or collagen 
|Vimentin; variable staining with actin, desmin, CD34 
|34% 
|-
|Aggressive [[angiomyxoma]] 
|Infiltrative 
|Uniformly distributed medium-sized blood vessels often with prominent hyalinization 
|Low to moderately cellular, evenly distributed round, spindled or stellate cells 
|Loose myxoid to focally collagenous 
|Vimentin, desmin, SMA{{ref|1|1}}, MSA{{ref|2|2}}, estrogen and progesterone receptor 
|36–72% 
|-
|Angiomyofibroblastoma 
|Well circumscribed 
|Abundant thin-walled blood vessels 
|Alternating hypercellular and hypocellular areas, perivascular condensations of spindled to epithelioid [[stromal cells]] 
|Collagenous to edematous with minimal mucin 
|Vimentin, desmin, CD34, estrogen and [[progesterone receptor]] 
|No recurrences reported, but rare cases of sarcomatous degeneration 
|-
|[[Superficial acral fibromyxoma]] 
|Pushing to infiltrative 
|Mild to moderately accentuated vasculature 
|Moderately cellular, spindle and stellate cells with a storiform to fascicular pattern, variable mast cells 
|Myxoid to collagenous 
|CD34, [[EMA]]{{ref|3|3}}, [[CD99]] 
|Recurrence rare and primarily for incompletely excised lesions 
|-
|[[Neurothekeoma]] (Nerve sheath myxoma)
|Well circumscribed, multilobular 
|Hypovascular 
|Moderately cellular, spindled cells in fascicles and whorls 
|Nests of cells separated by collagenous bundles 
|S-100, EMA{{ref|3|3}}
|47% if incompletely excised
|[[Image:Neurothekeoma2.JPG|center|100px]]
|}
1.{{note|1}}SMA, [[smooth muscle]] [[actin]]. 2.{{note|2}}MSA, muscle-specific [[actin]]. 3.{{note|3}}EMA, [[MUC1|epithelial membrane antigen]].

== Symptoms ==
Symptoms associated with cardiac myxomas are typically due to the effect of the mass of the tumor obstructing the normal flow of blood within the chambers of the heart. Because pedunculated myxomas are somewhat mobile, symptoms may only occur when the patient is in a particular position.

Some symptoms of myxoma may be associated with the release of [[interleukin 6]] (IL-6) by the myxoma.<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 | pmid=8343326 | doi=10.1136/hrt.69.6.565 | pmc=1025174}}</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 | pmid=1690543 | doi=10.1002/art.1780330313}}</ref>  High levels of IL-6 may be associated with a higher risk of embolism of the myxoma.<ref name="Wada-IL6">{{cite journal | author=Wada A, Kanda t, Hayashi R, et al. | title=Cardiac myxoma metastasized to the brain: potential role of endogenous interleukin-6 | journal=Cardiology | year=1993 | volume=83 | issue=3 | pages=208–11 | pmid=8281536 | doi=10.1159/000015180}}</ref>

Symptoms of a cardiac myxoma include<ref name="Fisher-Cardiacmyxoma">{{cite journal | author=Fisher J. | title=Cardiac myxoma | journal=Cardiovasc Rev Rep | year=1983 | issue=4 | pages=1195–9}}</ref>:
* [[Dyspnea]] on exertion
* [[Paroxysmal nocturnal dyspnea]]
* [[Fever]]
* [[Weight loss]] (see [[cachexia]])
* Lightheadedness or [[Syncope (medicine)|syncope]] (Loss of consciousness)
* [[Hemoptysis]]
* Sudden death
* [[Tachycardia]] or milder heartrate, ie 75 - 100 cycl/min

== Treatment ==
Myxomas are usually removed surgically.  The surgeon removes the myxoma, along with at least 5 surrounding millimeters of atrial septum.  The septum is then repaired, using material from the [[pericardium]].

== See also ==
* [[Cutaneous myxoma]]
* [[Carney complex]]
* [[Myxomatosis]]
* [[Primary tumors of the heart]]

==References==
{{reflist|2}}

== External links ==
* {{GPnotebook|-435814399}}
* {{MerckHome|03|031|b}}
* [http://pie.med.utoronto.ca/TEE/TEE_content/TEE_synopses_myxoma.html Toronto General Hospital Department of Anesthesia VIRTUAL TEE pathology section: Cardiac Myxoma (with video)]

{{Soft tissue tumors and sarcomas}}
{{Heart and thymus neoplasia}}

[[Category:Cardiology]]
[[Category:Types of cancer]]

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[[uk:Міксома]]
[[Category:2Fix]]