RS is a life-threatening complication of CLL, with a median survival of about 10 months. It may involve extranodal sites including gastrointestinal tract, lungs, kidneys, skin, and heart. We reported a case of rapid development of cardiac diffuse large B-cell lymphoma in a patient with preexisting CLL.
The RS transformation process is insidious and nonspecific, which is often challenging to diagnose and can be missed occasionally. Depending on the location, they can present with various cardiopulmonary symptoms, such as chest pain, dyspnea, syncope, heart failure, pericardial effusion, valvular dysfunction, and conduction abnormalities [4]. In this case, the patient complained of chest pain and palpitation with elevated high-sensitive troponin on her first admission. However, physical examination, echocardiography, and coronary angiography revealed no significant abnormalities. It is surprising that the repeated echocardiography performed one month after the first admission found a large and irregular cardiac mass. This cardiac mass developed rapidly and invaded the myocardium, so it is likely to be a malignant tumor with a poor prognosis.
Accurate differentiation of cardiac mass is often difficult and an erroneous diagnosis may lead to unnecessary surgery or inappropriate anticoagulation. The advance of the modern imaging tools, such as contrast-enhanced ultrasound imaging, computed tomography (CT), and cardiac magnetic resonance imaging (MRI), increases the likelihood of preoperative diagnosis. However, these imaging modalities have their own drawbacks, such as radiation damage of the cardiac CT, as well as time-consuming and expensive feature of cardiac MRI. More recently, contrast-enhanced echocardiography has been shown to be useful in distinguishing different types of cardiac masses, including thrombus, benign and malignant tumors. Takeuchi et al. found that contrast echocardiography could help detect the intracardiac thrombus in experimental animals because a thrombus retains its low echogenicity during chamber opacification [5]. It is well known that most malignant tumors have abundant neovascularization to supply the rapidly growing tumor cells, whereas the benign tumors, such as fibroma and myxomas, generally have poor blood supply and thrombi are avascular. To differentiate a thrombus from an intracardiac tumor, real-time imaging of very low mechanical index (MI) imaging with high MI flash should be used [6]. To our knowledge, few reports have reported contrast-enhanced echocardiography of cardiac lymphoma. In our case, myocardial contrast echocardiography revealed a large multilobulated mass measuring about 75.4×37.5mm, occupying almost the entire right ventricle and infiltrating the free wall of right ventricle.
The contrast agent quickly entered the mass several cardiac cycles after the injection of the contrast agent and the contrast enhancement of the mass was higher than that of the normal myocardium. Combined with the patient's prior CLL, the appearance of the echocardiography suggested a cardiac lymphoma. Histological examination confirmed the diagnosis of cardiac diffuse large B-cell lymphoma. There is no standard treatment strategy for the RS transformation. Chemotherapy, chemoimmunotherapy, and stem cell transplantation are several options, determined by histological type and disease extension [7]. In a study of 74,116 patients with CLL/SLL,530 patients developed RS transformation during follow up. The median age of RS diagnosis was 66 years and the median time from the diagnosis of CLL/SLL to the development of RS was approximately 4 years. RS patients had a poor outcome with a median survival of 10 months [8].
In summary, we described herein a case of a patient with cardiac presentation of Richter's transformation. Given the poor prognosis of RS, every effort should be made to diagnose these patients as early as possible. Our case also provides some experience in the diagnosis of cardiac lymphoma by contrast-enhanced echocardiography.