Atrial Myxoma
Account for 50% of benign cardiac tumours
Most commonly present in 30-60yrs age group, more common in females
Seen in 0.0017% - 0.03% of cases in autopsy studies (rare)
May be familial as part of the “Carney Complex” which is an autosomal dominant condition associated with PRKAR1A gene mutation. Results in abnormal skin pigmentation and multiple tumours in heart, skin and lungs.
Histology
- Features of lepidic cells with "myxoid" stromal findings
- Arise from cells in fossa ovalis
- Pedunculated gelatinous mass
- May be friable or villous in 35% of cases
Clinical features
- Characteristic “plop” heard in early diastole as myxoma obstructs the mitral valve
- “Platypnoea” where breathlessness improves on lying flat as the myxoma moves out of the mitral valve entrance
- Clinical features of mitral stenosis (Loud S1, pedal oedema, pleural effusions etc…)
- Constitutional symptoms such as fever and weight loss seen in 30% with associated rises in CRP and ESR. These are caused by IL-6 release from the myxoma itself and is associated with larger myxoma size
- Arrhythmias and heart block due to myocardial invasion
- Pericardial effusion with possible progression to tamponade
- Usually attached to the interatrial septum as derived from embryonic fossa ovalis tissue
TOE findings
Locations - LA = 75%, RA 20%, elsewhere = 5%
- May resemble a thrombus on echo
- Be wary of TOE insertion as this has been noted in case reports to dislodge atrial masses in some case reports
![Reference [1] Relationship of left atrium to adjacent structures and the oesophagus](https://images.spr.so/cdn-cgi/imagedelivery/j42No7y-dcokJuNgXeA0ig/fabb4a31-9ab0-4997-8291-851c3ad1bc6b/screenshot_2025-10-23_at_11.21.29/w=1920,quality=90,fit=scale-down)
Atrial myxoma vs thrombus
Feature | Atrial Myxoma | Atrial Thrombus |
Typical Location | Within the body of the atrium | Often in the left atrial appendage |
Attachment | Has a stalk or pedicle | Has a wider base |
Mobility | Mobile and free-moving | Immobile |
Vascularity | Show some vascularity (enhancement on contrast imaging) | Avascular (no enhancement) |
Clinical Symptoms | Can present with constitutional symptoms like fever, weight loss, arthralgia, or myalgia | Does not present with constitutional symptoms. Increased association with AF |
Anaesthetic Management Considerations
- Potential for pre-operative deconditioning secondary to constitutional symptoms
- Assess for evidence of obstruction
- Document pre-operative neurological deficit if previous embolic events
- Pre-op management of anticoagulation
- Assessment of mitral or tricuspid inflow obstruction
- Caution on insertion of TOE probe
- Careful fluid management and inotrope titration in post-operative phase as loading conditions can alter dramatically following excision of obstructive lesions.
References