Let’s Get Visual: Left Atrial Myxomas

Atrial myxoma is a benign, noncancerous tumor usually occurring in the left atrium. Lesion size differs widely among patients, but generally ranges from 2 to 6 cm. Depending on the size and location, it may cause mitral valve obstruction and pulmonary hypertension.¹ We report a young female with a 7.5 cm left atrial myxoma.

Case presentation

This patient is a 45-year-old female with a known history of a spleenectomy post motor vehicle accident and a family history of premature coronary disease. She presented to the emergency room with chest pain increasing in severity over the past several days. The pain was retrosternal and radiated to both sides of the sternum. She denied nausea, vomiting, diaphoresis, palpitations, and shortness of breath. The patient stated she may have a hiatal hernia and related the pain to that. Past medical history included spleenectomy and partial hysterectomy. She had a negative history for hypertension, hypercholesterolemia, and diabetes. The patient had smoked about 1 pack of cigarettes a day for the last 20 years. She denies alcohol use. Her family history was significant, as her mother had a myocardial infarction at age 55. Lab values were within normal limits, except for an elevated white blood count, which coincided with the spleenectomy.

An electrocardiogram showed sinus rhythm, normal axis with nonspecific ST-T wave changes. Physical exam was normal, with heart sounds 2/6 systolic murmur and no diastolic murmur. There was no S3 or S4 gallop.

A computed tomography (CT) scan of the abdomen incidentally noted a partially imaged 3 cm size mass spanning the region of the mitral valve, with the bulk of the mass in the left ventricle (Figure 1). It was unclear if it was an intracardiac neoplasm or a large intraventricular thrombus.

Cardiac catheterization showed normal right heart hemodynamics. There was a preserved cardiac output at 8.8 liters per minute. Left heart hemodynamics were normal, without aortic stenosis. There was a right dominant coronary arterial system with normal coronary arteries. The patient had normal left ventricular systolic function with an ejection fraction of 65%. Transesophageal echocardiogram showed mild to moderate mitral valve regurgitation and a 7.5 cm myxoma (Video 1).

The surgical approach was a right anterior mini thoracotomy for removal of the myxoma (Figure 2). The myxoma was tethered to the atrium and approximately a centimeter away from the mitral annulus. The foot of the stalk was less than a centimeter in diameter. This stalk was excised with a generous portion of the surrounding underlying muscle. The mitral valve was tested, and was noted to be normal in function and structure. Pathology reported it as a cardiac myxoma, consistent with clinical and operative impressions.

Discussion 

Myxoma is a primary cardiac tumor which is considered rare. It most often begins on the atrial septum. About 75% of myxomas occur in the left atrium.² Myxomas are more common in women and may be familial (inherited).² Symptoms may occur at any time or may be nonspecific, as these tumors are usually slow growing. Symptoms occur with changes in body position. Symptoms and signs may include difficulty in breathing when laying flat or sleeping, chest pain, dizziness, and the sensation of feeling your heart beating. Signs and symptoms of left atrial myxomas may be similar to mitral stenosis and can include cough, color change in fingers, nail curvature, malaise, join pain, body swelling, and weight loss.² Surgery is needed, with possible valve replacement.² Myxoma is not a cancer, but can lead to complications if untreated, such as embolism, blockage of blood flow, and mitral valve damage.² Cases such as this one are visually amazing and gratifying, as this otherwise healthy individual had a great outcome. 

References

1. Buyukates M, Aktunc E. Giant left atrial myxoma causing mitral valve obstruction and pulmonary hypertension. Can J Surg. 2008 Aug; 51(4): E97-E98.
2. Atrial Myxoma: Medical Encyclopedia. Medline Plus. U.S. National Library of Medicine. Available online at https://www.nlm.nih.gov/medlineplus/ency/cle/007273.htm. Accessed July 6, 2016.

Disclosure: The authors report no conflicts of interest regarding the content herein.

The authors can be contacted via Bonnie McDonald, RN, CEPS, RCES, at bonnie.mcdonald@ahss.org