Cardiac Myxoma B065

Current RMA Instruments

Changes from previous Instruments:

ICD Coding:

• ICD-10-AM Codes: D15.1

Brief description

Cardiac myxoma is a benign (non- cancerous) tumour that arises within the heart, most commonly in the atria. Although it is the most common type of primary heart tumour, primary cardiac tumours are extremely rare overall. In comparison, cancers that spread to the heart from elsewhere in the body (metastatic tumours) are far more common than true cardiac myxomas. 

Confirming the diagnosis

To confirm the diagnosis, histological evidence must be obtained. A cardiac myxoma may be suspected when a mass within the heart chambers is found on cardiac imaging such as echocardiogram, CT or MRI. However, the tumour tissue needs to be examined under a microscope to confirm the diagnosis is a myxoma and not another tumour type. 

Diagnostic assessment and management requires the involvement of a cardiologist and/or cardiac surgeon. 

Additional diagnoses covered by SOP

• Atrial myxoma
• Left/right atrial myxoma

Conditions that are excluded from SOP

• Papillary fibroelastoma (type of benign cardiac tumour) #
• Cardiac sarcoma * - Soft Tissue Sarcoma SOP
• Angiosarcoma * - Soft Tissue Sarcoma SOP
• Other primary cardiac tumours #

* another SOP applies

^# non- SOP condition

Clinical onset

The clinical onset refers to the earliest point in time, as identified by the treating doctor, when symptoms or signs consistent with a cardiac myxoma were first observed, prior to formal confirmation of the diagnosis. 

Cardiac myxomas may be found incidentally on imaging, or they may cause symptoms that mimic other heart conditions, such as shortness of breath, chest discomfort, fainting episodes or signs of impaired blood flow. 

Clinical onset may therefore correspond to the time when a mass was first detected on cardiac imaging and later confirmed to be a myxoma, or when symptoms that were ultimately attributed to the tumour initially appeared. 

Clinical worsening

When considering potential clinical worsening, it is important to determine whether any deterioration is beyond the expected progression in a person with a known cardiac myxoma. 

For this condition, having blunt force trauma to the chest can be a possible trigger for clinical worsening. This is because blunt force trauma to the chest can cause a cardiac myxoma to break up and embolise to multiple places throughout the body. The emboli can lodge in the major blood vessels, and the vessels of the brain, organs and the limbs, causing life-threatening ischaemia (part of the body not getting enough blood and oxygen) and infarction (part of the body has died because the blood supply was cut off for too long).

The only other possible cause of clinical worsening is the inability to obtain appropriate clinical management. Standard treatment generally involves prompt surgical removal (resection) of the tumour. Without timely management, the tumour may continue to grow, obstruct blood flow, or lead to complications such as embolic events. Assessment by a cardiologist or cardiac surgeon is recommended when evaluating whether true clinical worsening has occurred.