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 .