Myxoma: Symptoms, Types, Causes and Treatment

Myxoma is a term that encompasses a group of rare, typically benign tumors arising from connective tissue. The most clinically significant are cardiac myxomas, but other types, such as odontogenic myxomas, also exist. Understanding the symptoms, types, causes, and treatment options is crucial for both patients and healthcare providers, given myxomas' ability to mimic other diseases and their potentially serious complications. This comprehensive guide synthesizes the latest research to provide a clear and informative overview of myxoma.

Symptoms of Myxoma

Myxomas are often called "the great imitators" because their symptoms can be subtle, nonspecific, or mimic other conditions. Early recognition is essential due to the risk of severe complications, especially with cardiac myxomas, which can cause obstruction, embolization, or systemic symptoms.

Symptom	Frequency/Notes	Associated Type	Source(s)
Dyspnea	Most common, up to 95% of cases	Cardiac (atrial)	1 2 7 12
Palpitations	Often reported, sometimes with arrhythmias	Cardiac	1 2 12
Chest Discomfort	May mimic ischemic heart disease	Cardiac	1 2 7
Constitutional	Fever, weight loss, fatigue	Cardiac	1 2 4 5
Embolization	Stroke, rash, peripheral emboli	Cardiac (left-side)	1 3 4 5 6 12
Syncope	Common with obstruction	Cardiac	1 2 4 7
Edema	Especially pedal edema	Cardiac (right-side)	2 4 7
Cutaneous Signs	Rash, skin lesions (sentinel rash)	Cardiac	3
Asymptomatic	Incidental discovery	Cardiac, Odontogenic	6 12 10

Table 1: Key Symptoms

Understanding the Symptoms

Cardiac Myxoma: The Classic Triad

Cardiac myxomas present with a triad of symptoms:

• Intracardiac Obstruction: The tumor may physically block blood flow inside the heart, leading to symptoms similar to valve disease. This includes shortness of breath (dyspnea), especially when lying down or during exertion, and sometimes syncope (fainting) due to interrupted blood flow. Obstruction is more pronounced with larger tumors or those positioned near heart valves 1 2 4 5 7 12.

• Embolic Events: Myxomas are friable, meaning pieces can break off and travel through the bloodstream. In left-sided tumors, this can result in strokes or peripheral emboli causing sudden neurological deficits or limb ischemia. Right-sided tumors may cause pulmonary embolism. Rarely, emboli can cause skin manifestations — such as "sentinel rash" on hands, feet, or face — representing microemboli in dermal vessels 1 3 4 5 6 12.

• Constitutional Symptoms: These can include fever, fatigue, weight loss, and malaise, sometimes mimicking autoimmune or inflammatory diseases. These symptoms are thought to be mediated by cytokines like interleukin-6 produced by the tumor 1 2 4 5 6 8.

Less Common and Unique Presentations

• Palpitations and Arrhythmias: Tumor movement or irritation of the heart lining can cause irregular heartbeats or sensations of fluttering 1 2 12.
• Edema: Right-sided myxomas may lead to swelling of the legs and feet (pedal edema) due to impaired venous return 2 4 7.
• Cutaneous Signs: New research suggests that skin rashes associated with myxomas, traditionally classified as constitutional, are actually embolic phenomena 3. These rashes, often on the extremities or face, can sometimes precede more severe embolic events.
• Asymptomatic Cases: Some myxomas, particularly smaller or incidentally found odontogenic myxomas, cause no symptoms and are discovered during imaging or dental exams 6 10 12.

Types of Myxoma

Not all myxomas are the same. Their clinical behavior, location, and management vary significantly.

Type	Common Location	Notable Features	Source(s)
Cardiac Myxoma	Left atrium (75-80%)	Most common, can embolize	1 2 4 5 6 7 12
Right Atrial	Right atrium (15-20%)	Edema, right heart failure	4 6 7
Biatrial/Ventricular	Both atria/ventricles	Rare, more complex	1 6 7
Polypoid	Heart (usually atria)	Obstructive symptoms	5
Papillary	Heart	More embolic events	5
Odontogenic Myxoma	Jaw (mandible/maxilla)	Painless jaw swelling	10
Familial Myxoma	Multiple sites, younger	Carney complex, recurrence	5 6 8

Table 2: Myxoma Types

Exploring Myxoma Types

Cardiac Myxoma

• Left Atrial Myxoma: Most common site (75-80%). Arises near the fossa ovalis. Typically presents in adults, more often females, and is associated with the highest risk of embolic and obstructive symptoms 1 2 4 5 6 7 12.
• Right Atrial Myxoma: Accounts for 15-20% of cases. More likely to cause right-sided heart failure symptoms — such as peripheral edema and hepatic congestion — due to impaired blood return to the heart 4 6 7.
• Biatrial and Ventricular Myxomas: Rare, but can occur in both atria or the ventricles, sometimes as part of familial syndromes 1 6 7.

Morphological Types

• Polypoid Myxomas: Usually larger, with a stalk, and prone to causing obstruction of blood flow 5.
• Papillary Myxomas: More fragile and prone to fragment, leading to a higher risk of embolic complications 5.

Odontogenic Myxoma

• Location: Occurs in the jaw, most frequently the mandible.
• Presentation: Painless swelling or expansion of the jaw, sometimes causing tooth displacement. Rarely, it can be aggressive and recur after removal 10.

Familial Myxoma (Carney Complex)

• Genetics: Associated with mutations in the PRKAR1A gene.
• Features: Multiple myxomas (cardiac and extracardiac), pigmented skin lesions, and endocrine abnormalities. Higher risk of recurrence after surgery 5 6 8.

Causes of Myxoma

Understanding what causes myxomas is key to both prevention in high-risk groups and early detection.

Cause/Factor	Description	Associated Type	Source(s)
Sporadic Mutation	Random genetic change, most common	Cardiac, Odontogenic	5 6 8
Familial/Genetic	PRKAR1A mutation (Carney complex)	Familial cardiac	5 6 8
Mesenchymal Origin	Derived from primitive stem cells	Cardiac, Odontogenic	5 6 8 10
Cytokine Activity	Tumor produces interleukin-6, EGFs	Cardiac	5 8
Unknown/Idiopathic	No clear cause in many cases	All	5 6 10

Table 3: Causes of Myxoma

Delving into the Causes

Genetic and Familial Forms

• Carney Complex: A hereditary syndrome marked by the presence of multiple myxomas (cardiac and non-cardiac), skin pigmentation, and endocrine tumors. This is due to mutations in the PRKAR1A gene. Familial cases tend to occur at a younger age and are more likely to recur after surgery 5 6 8.

Sporadic Myxoma

• Most Common: The majority of myxomas arise due to spontaneous, non-inherited genetic mutations. There is no clear environmental or lifestyle risk factor identified 5 6 8.

Cellular Origin

• Mesenchymal Cells: Myxomas are thought to originate from primitive pluripotent mesenchymal stem cells, which can differentiate into multiple tissue types. This explains their potential to arise in various locations, such as the heart and jaw 5 6 8 10.

Molecular and Cytokine Factors

• Cytokine Production: Cardiac myxomas often secrete inflammatory cytokines, most notably interleukin-6 (IL-6). These can cause systemic symptoms such as fever and weight loss and may contribute to the tumor's ability to evade the immune system 5 8.
• Growth Factors: The tumor may also produce endothelial growth factors that contribute to its vascularity and potential for embolization 5 8.

Odontogenic Myxoma

• Origin in Dental Tissue: Believed to arise from the ectomesenchyme of developing teeth. There is no well-established genetic or environmental cause, though some suggest a link to undifferentiated mesenchymal cells in the jaw 10.

Treatment of Myxoma

Timely and effective treatment of myxoma is vital due to the risk of severe complications. The mainstay of therapy is surgical excision, but approaches and considerations differ depending on the type and location.

Treatment	Indication/Approach	Success/Prognosis	Source(s)
Surgical Excision	First-line, all symptomatic cardiac cases	Low risk, excellent outcome	1 4 5 6 7 8 12
Minimally Invasive	Robotic/endoscopic, selected cases	Increasing use	5 8
Segmental Resection	Large odontogenic jaw tumors	Low recurrence	10
Enucleation/Curettage	Small odontogenic jaw tumors	Higher recurrence risk	10
Long-term Follow-up	All cases, especially familial	Monitor for recurrence	1 6 12
Oncolytic Virotherapy	Research stage (cancer therapy)	Not for benign myxoma	9 11 13

Table 4: Treatment Approaches

Treatment in Depth

Cardiac Myxoma

• Surgical Resection:

  • Standard of Care: All symptomatic or incidentally discovered cardiac myxomas should be surgically removed as soon as possible due to the risk of embolism or sudden cardiac death 1 4 5 6 7 8 12.
  • Minimally Invasive Surgery: Growing trend toward minimally invasive or robotic-assisted techniques, offering shorter recovery and less trauma in eligible patients 5 8.
  • Prognosis: Surgical removal is highly effective, with low operative risk, excellent long-term survival, and low recurrence (usually <5%). Recurrence is higher in familial cases 1 6 12.
  • Combined Procedures: Sometimes performed alongside other cardiac surgeries, such as valve repair, if indicated 12.

• Follow-Up:

  • Echocardiographic Monitoring: Regular imaging is recommended, especially in familial cases, to detect recurrence early 1 6 12.

Odontogenic Myxoma

• Surgical Management:
  • Small Tumors: Enucleation and curettage (conservative surgery) can be effective, but there is a higher risk of recurrence 10.
  • Large Tumors: Segmental resection of the jaw with immediate reconstruction is preferred for larger or aggressive tumors, with lower recurrence rates 10.
  • Long-Term Follow-Up: Essential to monitor for recurrence, especially after conservative treatment 10.

Experimental and Research Therapies

• Oncolytic Myxoma Virus: While not used for benign human myxomas, the myxoma virus is being studied as an oncolytic (cancer-killing) virus in experimental therapies targeting malignant tumors like multiple myeloma and solid tumors. It is not currently relevant for benign myxoma treatment 9 11 13.

No Effective Medical Therapy

• There are currently no medications that can shrink or eliminate myxomas. Surgery remains the only curative approach 4 5 6 7 8 10 12.

Conclusion

Myxomas are a rare but critical group of tumors, most notably affecting the heart and jaw. Their varied symptoms can make diagnosis challenging, but awareness of the classic triad — obstruction, embolization, and constitutional symptoms — is key. Timely surgical intervention offers excellent outcomes, especially when followed by long-term monitoring for recurrence.

Key Takeaways:

• Symptoms: Myxomas can present with a triad of cardiac obstruction, embolic events, and constitutional symptoms, but may also be asymptomatic or mimic other conditions 1 2 4 5 6 7 12.
• Types: Most commonly found in the left atrium of the heart, but can also appear in the right atrium, both atria, ventricles, or jaw (odontogenic myxoma). Familial cases are associated with genetic syndromes 1 2 4 5 6 7 10 12.
• Causes: Usually sporadic, but some cases are familial, particularly as part of Carney complex. Myxomas arise from mesenchymal stem cells and may secrete cytokines like IL-6 5 6 8 10.
• Treatment: Surgical removal is the cornerstone, with minimally invasive options emerging. Long-term follow-up is essential, especially in familial cases. No effective drug therapy exists; research on myxoma virus as a cancer therapy is unrelated to benign myxoma management 1 4 5 6 7 8 9 10 11 12 13.

Being aware of myxoma's diverse faces ensures timely diagnosis and treatment, preventing potentially life-threatening complications.