Discussion
Cardiac lymphoma is an extremely rare disorder and the tumor presents with various clinical manifestations [1]. Our patient mainly presented with fatigue and weakness, and these symptoms might be resulted by the pendulous mass affecting normal hemodynamics. Serious atrioventricular block was diminished after removal of the tumor, which might be caused by the changed hemodynamics and thereby lead to ischemia of atrioventricular node. Besides, whether clinical manifestations of the patient are affected by secretory feature of lymphoma has not been identified.
There are still lack of unified diagnostic criteria for primary cardiac lymphomas. At present, PCL mainly refers to non-Hodgkin’s lymphoma involving only the heart and/or pericardium, as well as non-Hodgkin’s lymphoma with cardiac manifestations [5]. PCL is highly aggressive and could involve in the cardiac chamber (especially the right atrium), and even extracardiac sites, which is often multifocal [5]. The pathological subtypes of PCL cases reported include diffuse large B-cell lymphoma, Burkitt lymphoma, T-cell lymphoma and small lymphocytic lymphoma, among which diffuse large B-cell lymphoma is the most common subtype [6]. Intriguingly, it has reported that the B-cell lymphoma cells can embed fibrin thrombus and futher lead to formation of the Fibrin-associated large B-cell lymphoma, which may be associated with Epsteine-Barr virus. Fibrin-associated large B-cell lymphoma is thought to hardly invade myocardium , and seems has a better prognosis[7].
Well-documented evidence have reported that imaging modalities of cardiac lymphoma are various [1, 8]. Although Image modalities, including echocardiography, enhanced computed tomography (CT), and magnetic resonance image (MRI), are helpful in the detecte characterisation, for diagnosis prior to histological examination is difficult[5, 6]. Herein, the definite diagnosis of cardiac tumor requires histological examination. Seldom cases have reported that cardiac lymphoma coexist with myxoma and the mechanisms are obscure [9]. We have first reported a malignant tumor that had a complete fibrous capsule similar to myxomawith ECG revealing intermittent bradyarrhythmia. Accordingly, this case reminds us that diagnosis for cardiac myxoma should be caution.
At present, the definite standard treatment for PCL patients still remains absent. Therefore, an aggressive therapeutic approach to isolated cardiac lymphoma remains disputed [3, 9]. Considering the patient’s condition and that the whole-body enhanced CT scan did not find lymphadenectasis or other suspicious masses, there is no symptomatic lymphomatous cardiac infiltration at diagnosis and we did not administer further treatment for this 85-year-old man.
In conclusion, cardiac lymphomas are extremely rare with various clinical manifestations which could easily lead to misdiagnosis, subsequently, causing a poor outcome. Herein, we should be caution for the possibility of cardiac malignant tumours which need histological examination for diagnosis .