A 49-yr-old woman presented to her general practitioner (GP) with shortness of breath on exertion and mild ankle swelling for few weeks. She was a smoker and initial impression was that she probably suffered from smoking induced chronic obstructive pulmonary disease. Her BNP was slightly raised at 156 pg/ml and hence her GP requested for an open access echocardiogram (TTE) which showed a mass in left atrium. A transoesophageal echocardiogram (TOE) was arranged for further evaluation and it showed the following-
As you can see in transoesophageal echocardiogram, there was a mass in left atrium attached to interatrial septum with a stalk and projecting into the left ventricle through the mitral valve causing obstruction in mitral inflow in diastole. This echo appearance is typical of left atrial myxoma.
- Myxoma is the most common primary cardiac tumour and accounts for 30-50% of all primary tumours pf the heart. Myxomas are usually single and occur in the left atrium in 75% cases where they most commonly arise from the area of fossa ovalis. Rarely myxoma can be a part of Carney Syndrome (Autosomal dominant, multiple myxoma formation in cardiac and exrtracardiac tissue, spotty skin pigmentation, endocrine hyperactivity, other tumours like testicular tumour and pituitary adenoma). On echocardiogram myxomas can appear smooth surfaced but is more commonly irregular. They are typically nonhomogeneous in texture with lucent centres or areas of calcification.
- Annual incidence is around 0.5 per million population (1)
- Majority of the patients present with one or more of the classic triad of obstructive, embolic or constitutional features
Obstructive symptoms and signs–dizziness, sob, cough, pulmonary oedema and heart failure due to obstruction to mitral inflow by the tumour
Embolic manifestations — due to tumour embolism to systemic or pulmonary circulation depending on the location of the tumour
Constitutional features– fever, weight loss, fatigue, myalgia, arthralgia, muscle weakness, Raynaud’s syndrome. They are believed to be due to IL-6 released by myxoma tumour cells (2).
- Transthoracic /trans-oesophageal echo is diagnostic in typical cases. TOE is more sensitive and specific compared to TTE. CT and Cardiac MR are helpful in case of small tumours and in cases with atypical appearances
- Treatment is surgical removal as early as possible. There is about 3% chance of recurrence in sporadic cases though a more recent report found no recurrence after a mean follow up 72 months after surgical excision in 82 cases of LA myxoma (3). Chance of recurrence is higher in familial cases (20%)
References–
- MacGowan SW, Sidhu P, Aherne T, Luke D, Wood AE, Neligan MC, McGovern E. Atrial myxoma : national incidence, diagnosis and surgical management. Ir J Med Sci. 1993 Jun;162(6):223-6.doi: 10.1007/BF02945200
- Mendoza CE, Rosado MF, Bernal L. The role of interleukin-6 in cases of cardiac myxoma. Clinical features, immunologic abnormalities, and a possible role in recurrence. Tex Heart Inst J. 2001. 28(1):3-7.
- Vroomen M, Houthuizen P, Khamooshian A, Soliman Hamad MA, van Straten AH. Long-term follow-up of 82 patients after surgical excision of atrial myxomas. Interact Cardiovasc Thorac Surg. 2015 Aug. 21 (2):183-8.