primary cardiac lymphoma ( pcl ) is a very rare neoplasm originating in the heart . traditionally , pcl is defined as an extranodal lymphoma limited to the heart or pericardium .
however , some previous reports demonstrated pcl cases with extracardiac involvement.1,2,3 pcl occupies 1.3% of primary cardiac tumors and 0.5% of extranodal lymphomas.4 patients with pcl generally complain of nonspecific symptoms such as dyspnea , edema , and arrhythmia.5,6 treatment of pcl is variable because the optimal treatment strategy has not yet been established .
however , previous studies have shown that chemotherapy is the most effective therapy.5,7 in this report , we delineate a case of diffuse infiltrative type of pcl with spread to the mediastinum and cervical lymph nodes .
a 48-year - old man visiting the korea university ansan hospital presented with the symptoms of exertional dyspnea and cough .
chest radiography showed pleural effusion , pulmonary congestion , and cardiomegaly . in a transthoracic two - dimensional echocardiography , a large amount of pericardial effusion and diffuse cardiac wall thickening
we performed cardiac magnetic resonance imaging ( mri ) for differential diagnosis of myocardial infiltrative diseases such as cardiac amyloidosis .
however , there was no lymphadenopathy or a mass lesion in the mri images ( fig .
however , the myocardial biopsy showed myocyte hypertrophy , and the pericardial biopsy showed chronic inflammation with fibrosis and the congo red staining was negative
. we could not identify a definite cause of the pericardial effusion ; hence , the patient underwent conservative treatment and received outpatient follow - up .
chest computed tomography ( ct ) revealed an infiltrative soft tissue mass in the anterior mediastinum and diffuse thickening of all ventricular and atrial walls ( fig .
immunohistochemical staining was positive for cd45 , but owing to the lack of specimen tissue , we could not perform more tests .
clinically , we suspected a diagnosis of fibrosing mediastinitis , and glucocorticoids were used empirically .
we prescribed prednisolone 60 mg daily for 1 month , which was tapered to 15 mg per day within 5 months . after tapering of prednisolone
ten months later , the patient complained of a nontender mass on the right side of the neck ( fig .
immunohistochemistry demonstrated a large lymphoid neoplasm , which was positive for cd45 , cd79a , and cd20 .
finally , the patient was diagnosed with primary cardiac diffuse large b cell lymphoma ( dlbcl ) .
he commenced chemotherapy with rituximab and chop ( cyclophosphamide , doxorubicin , vincristine , and prednisolone ) .
after the second cycle of chemotherapy , we performed chest ct . in the chest ct , the infiltrative lesion , involving the myocardium and multiple lymph nodes ,
3b ) compared with the chest ct performed before the r - chop therapy ( fig .
3b ) . on the basis of this result , we are confident that the dlbcl originated in the heart and the final diagnosis was pcl . after 6 cycles of chemotherapy , chest ct and positron emission tomography scans were performed to assess the response to treatment .
he commenced radiation therapy ( total 40 gy ) for the cardiophrenic angle lymph nodes .
it is defined as an extranodal lymphoma limited to the heart or pericardium.4,5 histologically , diffuse large b cell type of non - hodgkin 's lymphoma is the most common of the pcls , and its incidence ranges from 60% to 81%.6,8,9 in previous reports , most of the cases showed a mass - like lesion.6 the right atrium is the most common site of invasion , followed by the right ventricle , left ventricle , and left atrium.7 patients commonly present with nonspecific , different symptoms ; and clinical findings such as dyspnea , arrhythmia , pericardial effusion , and congestive heart failure are observed.5,6 because of its nonspecific clinical manifestation , it is difficult to diagnose pcl .
imaging studies such as echocardiography , ct , and mri are helpful for the diagnosis of pcl . however , pathologic examination is the only way to obtain a definite diagnosis.10 chemotherapy is effective for treatment of any subtype of primary cardiac lymphoma .
a previous report demonstrated that rituximab in combination with the chop regimen has a good outcome in the dlbcl type of pcl.1,9,10 petric et al.5 stated that the median overall survival after diagnosis was 12 months . among the patients , the chemotherapy group had a longer overall survival up to 30 months.5
first , the pcl was observed as thickened myocardium without an intracardiac mass . to our knowledge , this is the second case report of a diffuse infiltrative pcl without an intracardiac mass.11 second , in this case , the dlbcl originated in the heart and delayed extracardiac involvement was noted .
two cases presented with an extracardiac metastasis at the first diagnosis.1,2 one case had a pcl involving only the heart at the primary diagnosis , but microscopic involvement of the lungs , peritoneal , and retroperitoneal adipose tissue was detected on autopsy.3 however , these cases did not clearly show delayed metastasis of the pcl to an extracardiac site .
our case clearly showed that the pcl had no extracardiac involvement initially but afterwards showed extracardiac involvement .
mediastinal lymph node biopsy was performed at the second admission , and lymphoma was suspected . however , because of insufficient specimens and refusal of the patient to undergo further testing , we could not confirm the diagnosis of lymphoma , and we administered steroids for a possible diagnosis of fibrosing mediastinitis . we think that the use of steroids led to an immunocompromised state , and this state may have contributed to the delayed extracardiac involvement .
it is well known that steroids have a lympholytic effect , and this effect probably caused a disturbance of the detection time from the symptom onset to the administration of proper treatment .
although this is only a hypothesis , clinicians should be aware of the possibility of delayed diagnosis of a pcl owing to the use of steroids .
despite these interesting points , this report had one large limitation . because we failed to confirm the diagnosis of pcl from previous cardiac and mediastinal biopsies , the tissues from the enlarged lymph node in the right neck were used to confirm the diagnosis of pcl .
although the biopsy was not performed at the primary site of lymphoma , given that the initial cardiac mri demonstrated diffuse cardiac infiltration without lymph node enlargements , it appears proper to diagnose pcl . in summary , we have reported a case of an infiltrative type of pcl without an intracardiac mass and with delayed extracardiac involvement .
 primary cardiac lymphoma ( pcl ) is an extremely rare and fatal neoplasm of the heart . 
 traditionally , it is defined as lymphoma involving the heart or pericardium . 
 pcl has a poor prognosis because of the diagnostic difficulty and its location . 
 we present the case of a 48-year - old man who presented with pericardial effusion and diffuse cardiac wall thickening . 
 we first suspected infiltrative heart disease . 
 however , even after performing a biopsy , we could not establish an accurate diagnosis . 
 after 20 months , primary cardiac diffuse large b cell lymphoma ( dlbcl ) was diagnosed by cervical lymph node biopsy . in this case , after chemotherapy , the dlbcl lesions , including cardiac wall thickening , improved . 
 the treatment outcome suggests that the diagnosis was diffuse infiltrative pcl with delayed extracardiac involvement . 
INTRODUCTION
CASE REPORT
DISCUSSION