The WHO classification of tumors of hematopoietic and lymphoid tissues divides DLBCL into several subtypes including GC B cell subgroup [23]. DLBCL is the most frequent lymphoma subtype, accounts for about one third of the newly diagnosed lymphoma cases worldwide [24]. The different subtypes show significant differences in pathogenesis and clinical manifestation and most importantly are treated differently from classical DLBCL. Therefore the exact origin of the malignant cell and its molecular background must be determined [23].
Cardiac metastases are rare, and usually develop clinically silent or have nonspecific symptoms. Therefore, they are difficult to diagnose and are frequently detected postmortem during an autopsy. In patients with lymphoma the cardiac involvement is seen in 8–15% of the cases and most of them are of B cell origin [25]. Clinical manifestations are highly variable, including heart failure, arrhythmias, valvular disease, and cardiac tamponade [26]. Due to the varying clinical presentations of cardiac lymphoma metastases the detection is often incidental.
If the signs and symptoms of cardiac disease are present non-invasive imaging is key in prompt diagnosis [27, 28]. Chest radiography may indicate cardiomegaly caused by pericardial effusion, abnormal shape of the heart, or lung congestion [8]. Echocardiography is the most frequently used non-invasive imaging technique to assess the heart. TTE is useful in the initial evaluation of suspected cardiac disease, but sometimes transesophageal echocardiography is required for a more accurate assessment [29]. The diagnostic accuracy of echocardiography is around 80% in the evaluation of suspected cardiac tumors [30]. CT and magnetic resonance imaging provide additional detail of the surrounding extracardiac structures, including the lungs, mediastinum and pleura [31]. Positron emission tomography (PET)/CT may provide additional utility and improved accuracy in earlier detection of metastases involving the heart [32].
There is no standard treatment of cardiac metastases in lymphomas. The therapy of choice is mostly influenced by the location of the metastasis and the patient’s condition. The individualized treatment often means interdisciplinary cooperation of oncologists, radiotherapists and surgeons [3].
In our case the patient showed nonspecific symptoms, such as effort dyspnea, chest discomfort, even fever. His physical status, laboratory and ECG findings supported the presence of more common conditions. Fever and crackles found on physical examination, the two-week-old history of chest pain and the fact that the patient is actively treated with chemotherapy due to hematological malignancy suggested pneumonia in the background. His ECG finding with the previously non-described incomplete right bundle branch block strengthen the possibility of pneumonia but also raised the possibility of pulmonary embolism and acute coronary syndrome. Therefore, the patient’s blood was tested for infection, d-dimer, and high-sensitivity troponin-T and chest X-ray was performed. The first result confirmed pneumonia but the high d-dimer and hsTnT indicated the need of further investigation. High d-dimer suggested the possibility of pulmonary embolism. He even admitted forgetting to administer his prophylactic LMWH the day before his admission.
Pulmonary embolism can be accompanied by elevated hsTnT level [33] and vice versa elevated d-dimer level may occur in ischemic heart disease [34]. The GRACE score of the patient was 101 points, his hsTnT level was high enough to fulfill a high-risk criterium for acute coronary syndrome. His Well’s score was 5.5 suggesting a moderate risk for pulmonary embolism [34]. The possibility of both conditions, myocardial infarction and pulmonary embolism, was present consequently, thus one of them must have to be excluded. We performed TTE to detect the presence of right ventricular dilatation as a sign for acute pulmonary embolism or myocardial hypo-akinesis due to myocardial infraction. TTE showed inferior akinesis, still, the possibility of pulmonary embolism was not clearly excluded. According to the guideline of the European Society of Cardiology if the patient’s initial evaluation suggests pulmonary embolism CT angiography is recommended before coronary angiography [33]. Chest CT can effectively exclude not only pulmonary embolism, but other causes of chest pain as well which, if untreated, can be associated with high mortality. Quick assessment of the chest CT showed no embolism. Thus the coronary angiography was immediately performed in correlation with the early invasive strategy [33], but no occlusion or significant stenosis was found in the coronary arteries. While the coronary angiography was done the fine analysis of the chest CT revealed the intramyocardial progression of the patient’s lymphoma.
His fever was caused by concomitant consolidation in the left lower lobe and was successfully cured by imipenem-cilastatin combination. High d-dimer was most likely the consequence of the patient’s primary disease, the lymphoma, and not the result of thromboembolism as we first predicted [35]. The high troponin-T level was observed because the lymphoma damaged the heart tissue leading to the release of this protein [33].
Most of his findings suggested thromboembolism, myocardial infarction or pneumonia in the background of his complaints rather than the presence of intramyocardial lymphoma.
This case illustrate that rarely healthy coronary arteries can cause inappropriate blood supply to the heart muscle if they are externally compressed by such a rare finding as an intramyocardial malignant lymphoid tissue. The patient was fortunate because of the early diagnosis (Table 2) and successful treatment of his cardiac lymphoma metastasis provided him almost a year survival.
To conclude, primary and secondary cardiac tumors are uncommon diseases. Their clinical symptoms are variable, acute coronary syndrome is among the rarest. Our patient’s case is unique because he presented the symptoms of more common conditions, which affect large populations, such as pulmonary embolism, pneumonia, ACS, aortic dissection, pneumothorax, rupture of the esophagus or pericarditis. The early diagnosis and management of these diseases in emergency department settings is crucial for the survival of the patient. But the patient’s findings revealed cardiac lymphoma metastasis which externally compressed the right coronary artery, leading to symptoms mimicking ACS. Fortunately, the quick diagnosis and efficient cooperation with cardiologists, radiologists and hematologists permitted the instant adequate therapy to the patient.