Left Atrial Myxoma

KEY FEATURES

ESSENTIALS OF DIAGNOSIS

• Symptoms of valvular dysfunction such as dyspnea

• Thromboemboli

• Constitutional symptoms (eg, fever, arthralgias, weight loss)

• Tumor plop sound in early diastole on auscultation

• Mitral systolic or diastolic murmurs

• Echocardiographic evidence of characteristic cardiac mass

GENERAL CONSIDERATIONS

• Primary cardiac tumors are rare, but left atrial myxoma is the most common in adults and is usually benign

• Mean age at discovery of left atrial myxoma is 50 years and is more common in women

• About 10% of left atrial myxomas are familial in an autosomal dominant pattern and present earlier (mean age 25 years)

• Carney’s complex is a rare cause and includes:

  • – Multiple cardiac myxoma

  • – Lentigines and blue nevi

  • – Breast fibroadenomas

  • – Pituitary and testicular tumors

  • – Primary pigmented nodular adrenocortical disease with Cushing’s syndrome

• About 75% of all cardiac myxomas occur in the left atrium, 20% in the right atrium, and 5% in the ventricles

• Left atrial myxomas usually are attached by a stalk near the fossa ovalis

CLINICAL PRESENTATION

SYMPTOMS AND SIGNS

• Patients may present with the classic triad of constitutional, systemic embolic, and mitral valve obstruction symptoms, but more often, they have 1 or 2 of these manifestations

• Constitutional symptoms:

  • – Weight loss

  • – Fatigue

  • – Fever

  • – Arthralgias

• Dyspnea from mitral valve obstruction or regurgitation

PHYSICAL EXAM FINDINGS

• Signs of pulmonary congestion—pulmonary rales, wheezing

• Auscultation:

  • – Loud S₁ due to delayed mitral closure

  • – Early diastolic tumor plop

  • – Mitral diastolic rumble

  • – Mitral regurgitation murmur

  • – Loud pulmonary component of S₂ if pulmonary hypertension present

  • – Occasional signs of right heart failure

DIFFERENTIAL DIAGNOSIS

• Cardiac thrombus

• Vegetations

• Flail or prolapsing leaflets

• Rheumatic mitral valve disease

• Connective tissue disease with Libman-Sacks endocarditis

• Other causes of stroke

• Other febrile illnesses

DIAGNOSTIC EVALUATION

LABORATORY TESTS

• Normochronic, normocytic, or low-grade hemolytic anemia

• Polycythemia, thrombocytosis, leukocytosis

• Elevated sedimentation rate and immunoglobulins

ELECTROCARDIOGRAPHY

• May show signs of left atrial enlargement

• Occasionally, atrial fibrillation

IMAGING STUDIES

• Chest x-ray:

  • – Enlarged left atrium

• Echocardiography is the imaging procedure of choice because of its ability to distinguish the tumor mass from the left atrial cavity into which it protrudes

  • – The stalk attached to the atrial septum and the mobile mass that moves toward or through the mitral valve in diastole and pops back into the atrium in systole is characteristic

  • – Transesophageal echo can provide more detailed anatomic information that may be needed in some cases to plan surgery

DIAGNOSTIC PROCEDURES

• Cardiac catheterization may be required in older ...