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Atrial Myxoma

Also called

Cardiac Myxoma

ICD-10

D15.1

Specialty

Cardiology

Onset

Insidious (progressive)

Reviewed

June 2026
On This Page

Overview

Cardiac myxoma is the most common primary tumor of the heart. It is usually benign and arises from primary connective tissue. Around 75% occur in the left atrium, usually attached to the interatrial septum. Right atrial myxomas are less common, while ventricular myxomas are rare. Symptoms mainly result from: Obstruction of intracardiac blood flow. Embolization of tumor fragments.

Etiology & Risk Factors

  • Exact cause is unknown.
  • Most cases are sporadic.
  • About 10% are hereditary:
    • Autosomal dominant inheritance
    • Associated with Carney syndrome

Pathophysiology

-Gross pathology

  • Usually pedunculated (attached by a stalk).
  • Gelatinous in consistency.

 

-Microscopic pathology

  • Scattered mesenchymal cells in a mucoid (gelatinous) matrix.
  • Surrounded by glycosaminoglycans.
  • Tumor cells produce VEGF.

 

-Mechanism of symptoms

  • Obstruction of the mitral valve opening causes symptoms similar to mitral stenosis.
  • Embolization may cause stroke or infarction in other organs.
  • IL-6 production by the tumor leads to constitutional symptoms.

Clinical Presentation

-Constitutional symptoms

  • Weight loss

  • Fever

  • Pallor

  • Digital clubbing

 

-Symptoms due to obstruction

  • Dyspnea on exertion

  • Orthopnea

  • Paroxysmal nocturnal dyspnea

  • Palpitations

  • Dizziness

  • Recurrent syncope

 

-Physical examination

  • Low-pitched mid-diastolic rumbling murmur at the apex

  • Characteristic “tumor plop” (early diastolic sound)

  • Murmur and heart sounds may change with body position.

  • Mitral regurgitation may occur due to valve damage.

 

-Symptoms due to embolization

  • CNS: TIA, stroke, seizures

  • Abdomen: Visceral infarction or hemorrhage

  • Lungs: Pulmonary embolization

Atrial Myxoma Overview
Atrial Myxoma Overview

History Taking

Important points include:

  • Progressive exertional dyspnea
  • Episodes of syncope
  • Palpitations
  • Orthopnea or PND
  • Constitutional symptoms (fever, weight loss)
  • History suggestive of embolic events (stroke, TIA, limb or abdominal ischemia)
  • Family history of Carney syndrome or hereditary cardiac myxoma

Investigations

1. Echocardiography — investigation of choice

  • Transthoracic echocardiography (TTE) is usually the initial investigation.
  • Demonstrates an intracardiac mass, typically arising from the left atrium.
  • Assesses:
    • Tumour size
    • Site of attachment
    • Mobility
    • Obstruction of the mitral valve
    • Effects on cardiac function

2. Transoesophageal echocardiography (TOE/TEE)

  • Provides better definition of the tumour, its attachment and mobility, particularly when TTE is inadequate.

3. ECG

  • May show non-specific abnormalities or atrial arrhythmias.
  • Not diagnostic.

4. Chest X-ray

  • May be normal.
  • Can demonstrate cardiac enlargement or pulmonary venous congestion when significant obstruction is present.

5. Laboratory investigations

  • May show inflammatory or constitutional abnormalities, including:
    • Anaemia
    • Raised inflammatory markers
  • These findings are non-specific and support the clinical picture rather than establish the diagnosis.

6. Cardiac CT/MRI

    • Can further characterise an intracardiac mass when echocardiography is inconclusive and help define its anatomical extent.

Diagnosis

-The diagnosis is primarily made by echocardiography.

 

-Typical diagnostic findings:

  • Mobile atrial mass
  • Usually located in the left atrium
  • Often attached to the interatrial septum
  • May prolapse through the mitral valve, producing functional obstruction.

 

–Differential diagnoses of an atrial mass include:

  • Atrial thrombus
  • Other cardiac tumours
  • Vegetations
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Management

1. Surgical excision — definitive treatment

  • Prompt surgical removal is the treatment of choice.
  • The tumour and its site of attachment/stalk are excised to reduce the risk of recurrence.
  • Surgery is indicated because of the risks of:
    • Embolisation
    • Cardiac obstruction
    • Heart failure
    • Sudden cardiovascular deterioration

2. Pre-operative assessment

  • Echocardiography defines the tumour and its haemodynamic effects.
  • Cardiac imaging may be used to assess anatomy and plan surgery.
  • Patients undergo standard assessment for cardiac surgery.

3. After surgery

  • Histological examination confirms the diagnosis.
  • Follow-up echocardiography is important because recurrence can occur, particularly in familial or syndromic cases.

Complications

  • Systemic embolization
  • Cerebral infarction (stroke)
  • Pulmonary embolization
  • Valvular damage causing mitral regurgitation
  • Sudden death
  • Tumor recurrence after incomplete excision or from another tumor focus

Prognosis

  • Generally favorable after surgical resection.
  • Recurrence can occur, especially after incomplete tumor removal.

Key Points / Clinical Pearls

  • Most common primary benign cardiac tumor.
  • About 75% arise in the left atrium, usually from the interatrial septum.
  • Classic auscultatory finding: “tumor plop.”
  • Symptoms are due to obstruction, embolization, and IL-6-mediated constitutional effects.
  • Echocardiography is the investigation of choice.
  • Immediate surgical excision is the definitive treatment because of the risk of embolization and sudden death.