What are the typical presentation, diagnostic workup, and management of atrial myxoma in adults?

Atrial Myxoma: Clinical Presentation, Diagnosis, and Management

Clinical Presentation

Atrial myxomas are the most common primary cardiac tumors in adults (incidence up to 0.2% in autopsy series) and typically present with a classic triad of constitutional, embolic, and obstructive cardiac symptoms. 1

Typical Symptoms

• Constitutional symptoms: Influenza-like illness, fever, malaise, weight loss, and fatigue 1
• Embolic manifestations: Stroke or transient ischemic attack (overall embolism rate of 25%), with villous tumors having greater embolic potential 2
• Obstructive symptoms: Heart failure, dyspnea, syncope, or sudden death from intracardiac blood flow obstruction 2, 1
• Asymptomatic presentation: Rare but can occur, with incidental discovery on imaging 3

Key Clinical Pitfall

The mechanism of stroke is embolic, either from thrombus formed on the tumor surface or embolization of tumor fragments themselves. 2 Patients with left-sided cardiac tumors have significantly increased stroke risk requiring urgent intervention. 2

Diagnostic Workup

First-Line Imaging: Echocardiography

Transthoracic echocardiography (TTE) is the diagnostic test of choice for initial detection and characterization of atrial myxomas. 2, 4

• Standard TTE findings: Typically reveals a pedunculated mass attached at the fossa ovalis on the left side of the atrial septum 1
• Limitations: Can miss uncommonly situated myxomas or smaller lesions 1

Advanced Imaging

Transesophageal echocardiography (TEE) is mandatory for definitive characterization, with sensitivity of 93-100% and specificity of 99%. 5

• TEE advantages: Superior visualization of attachment site, mobility, size, and detailed morphology 5
• When to use TEE: When TTE is suboptimal, to exclude atrial thrombus before cardioversion, or for surgical planning 2, 4

Cardiac MRI is the method of choice to differentiate intracardiac masses (myxoma vs. thrombus vs. malignant tumor). 5

• Additional role: Provides enhanced tissue characterization and can further define tumor extent before surgical planning 2
• Cardiac CT: Alternative imaging modality when MRI is contraindicated 2

Diagnostic Algorithm

1. Initial detection: TTE for any patient with unexplained heart failure, stroke, or constitutional symptoms 2, 1
2. Definitive characterization: TEE for detailed assessment of all suspected cardiac masses 5
3. Tissue differentiation: Cardiac MRI when diagnosis remains uncertain or to exclude malignancy 5
4. Avoid cardiac catheterization: Two-dimensional echocardiography has eliminated the need for invasive angiography in most cases 6

Histopathological Confirmation

• Definitive diagnosis: Requires macroscopic and histopathological assessment with positivity for endothelial cell markers (CD31 and CD34) 1
• Pathology obtained: At time of surgical resection, not via biopsy 1

Management

Surgical Treatment

Surgical excision is the only established and definitive treatment for cardiac myxoma and should be performed urgently to prevent life-threatening complications. 2

Specific Surgical Recommendations

For patients with stroke or TIA found to have a left-sided cardiac tumor, resection is beneficial to reduce the risk of recurrent stroke (Class IIa recommendation, Level of Evidence C-LD). 2

• Surgical technique: Complete excision including the tumor stalk and surrounding atrial septum to prevent recurrence 2, 6
• Approach: Cardiopulmonary bypass with en bloc resection of tumor and attachment site 2, 6
• Timing: Prompt surgical consultation required for all mobile atrial masses due to life-threatening embolization risk 5

Critical Management Principles

• Anticoagulation alone is insufficient: Mobile cardiac tumors require surgical removal, not medical management 5
• No role for preoperative catheterization: Modern echocardiography provides sufficient information for surgical planning in most cases 6
• Avoid tumor manipulation: Risk of intraoperative embolization necessitates careful surgical technique 2

Prognosis

Prognosis is excellent when treated with prompt surgical resection, with postsurgical survival rates analogous to overall survival in the age-matched general population. 1

• Recurrence rate: Low when complete excision of tumor base and surrounding septum is performed 2, 6
• Mortality if untreated: High due to embolic complications and cardiac obstruction 5

Special Considerations

For right-sided tumors or metastatic disease to the heart, consider paradoxical embolism through a patent foramen ovale. 2

• Anticoagulation: May be considered in select cases, but surgical excision remains definitive treatment 2
• Future research: Better understanding of risk modification from antiplatelet or anticoagulation therapy in particular tumor subtypes is needed 2