• Clinical science

Cardiac myxoma (Atrial myxoma)

Abstract

Cardiac myxomas are the most common type of primary tumor of the heart. They are usually benign and arise from primary connective tissue. Most cardiac myxomas arise sporadically; however, 10% are hereditary (following an autosomal dominant pattern). Even though they may develop in any chamber of the heart, most (∼ 75 %) cardiac myxomas arise in the left atrium, usually from the interatrial septum, while the rest occur in the right atrium (ventricular myxomas are rare). Clinical features are primarily caused by obstruction of the blood flow through the heart and include dyspnea on exertion, palpitations, syncope, weight loss, or even sudden death. Rarely, life-threatening conditions (e.g., stroke) may result from an embolization from the myxoma. Typical examination findings include abnormal heart sounds, such as a rumbling diastolic murmur over the apex or a characteristic “tumor plop.” The diagnosis is not easily established clinically because of the nonspecific nature of symptoms. Echocardiography is the diagnostic procedure of choice. Surgical resection of the tumor is the curative treatment of choice. The prognosis is usually favorable, but tumors can recur after inadequate resection.

Epidemiology

  • Most common primary cardiac neoplasm (usually benign)
  • Most common location: left atrium (∼ 75% of all cases)
  • Sex: > (3:1)
  • Peak incidence: 40–60 years

References:[1][2][3]

Epidemiological data refers to the US, unless otherwise specified.

Etiology

References:[2]

Clinical features

References:[1][2]

Diagnostics

Because of the nonspecific nature of the cardiac symptoms, the diagnosis is often only established much later in the course of the disease.

  • Echocardiography: diagnostic test of choice
    • The tumor is visualized as a pedunculated, heterogenous, mobile mass, usually present in the left atrium.
    • Helps assess tumor location, size, attachment, and mobility.
  • Other tests: CT and MRI scans help better visualize the intracardiac mass.

References:[2][4]

Pathology

  • Microscopic appearance:
    • Scattered mesenchymal cells within mucoid, gelatinous material
    • Produce VEGF
  • Macroscopic appearance: often pedunculated, gelatinous consistency

References:[1][5]

Differential diagnoses

The differential diagnoses listed here are not exhaustive.

Treatment

  • The only definitive treatment of cardiac myxoma is surgical resection.
  • Medical intervention may be required for the treatment of associated conditions like arrhythmias, heart failure, or embolism.

Recurrence may occur in cases of incomplete excision of the tumor, growth from a second focus, or intracardiac implantation from the primary tumor.

References:[1][2]