Left Sided Atrial Myxoma with Blood Supply from the Left Circumflex Artery in a 72 Year Old Women

History

This is  the case of a 77 year old female patient, who suffered from atypical angina both during exercise and at rest, partially releaved by oral nitrates. Here medical record was unremarkable except for well controlled hypertension treated with an ACE inhibitor for several years. Because of here anginal pain, she was prescribed aspirin 100 mg daily.

Findings

Clinical examination was normal except for a 2/6 mitral regurgitant murmur. Laboratory values were within the normal range except for a moderately elevated ESR (18 mm /h). On echocardiographic examination a 5x3 cm large, smooth and poorly mobile mass in the left atrium was detected (Fig 1), presumably fixed to the atrial septal wall and without signs of obstruction to the pulmonary veins or left atrial outflow. Furthermore, mild excentric left ventricular hypertrophy was noted (132 g/m2, relative wall thickness 42%) and signs of mild diastolic dysfunction were observed (E/A ratio < 0.8, velocity propagation 42 cm/s). CineMR of the tumor showed a quite homogenous but low signal intensity pattern, compatible with atrial myxoma with calcifications or hemosiderin deposits (Fig 2). Subsequent coronary angiography revealed normal coronary arteries and an abnormal vessel originating from the mid portion of the left circumflex artery supplying the tumor (Fig 3). On operation, the tumor was found to measure 4.5x3x3.5 cm, the consistency was jelly-like and the macroscopic diagnosis was left atrial myxoma. On histology, the tumor could be classified as myxoma not containing calcifications but substantial amounts of hemosiderin.

Discussion

Intracardiac primary tumors are infrequent (0.00017-0.28 per cent incidence on autopsy series) and myxomas are the most common type of primary cardiac tumor, comprising 30-50 per cent in most pathological series ^1-5. The mean age of sporadic myxomas is 56 years, and 70 per cent are females. Approximately 86 per cent of myxomas occur in the left atrium, and over 90 per cent are solitary with a usual attachment to the fossa ovalis ^5,6. The clinical signs and symptoms produced by cardiac myxomas include nonspecific manifestations, embolizations, and mechanical interference with cardiac function, but atypical or typical angina are rarely noted ⁷.

The vascularity of left atrial myxoma is usually poor, but some myxomas show high vascularity, usually with blood supply from coronary arteries, as noted by Van Cleemput to occur in 7 cases (37 per cent) out of 19 atrial myxomas, of which 3 myxomas (16 per cent) were supplied from the left circumflex artery ⁸. Left atrial myxoma blood supply from left circumflex arteries is a rare finding and has, to our knowledge, only been reported in 5 patients since 1988, of which only one patient suffered from atypical angina ^8-10.

The exact reason for atypical chest pain in our patient could not further be elucidated because of a contraindication for ischemia testing. However, in view of the normal coronary angiogram and only mild left ventricular hypertrophy, a hemodynamic relevant steal phenomenon may have occured with intermittent ischemia in the left circumflex territory.

Echocardiography is a readily available tool for the early detection of intracardiac masses and should be used as appropriate. MRI of cardiac masses does usually not help to differentiate different tumors using T1 weighted spin echo sequences and Cine MRI ¹¹, although lipomas are easily characterized by this technique ¹².

Conclusion

Primary cardiac tumors are a relatively rare finding and most commonly consist of left atrial myxomas in elderly women. Clinical presentation is unspecific, but echocardiography helps to send patients quickly to adequate therapy with surgical removal of the tumor. Diagnosis of myxomas vascularized from coronary arteries is possible with coronary angiography. MRI is generally not necesseray for decision making.

Figure 1                                                  Figure 2                           

Figure 3

Literature