68. Unusual presentation of mediastinal lymphoma and role of cardiac MRI

Abstract

Diffuse large B cell lymphoma (DLBCL) is the most common histologic subtype of non-Hodgkin lymphoma (NHL) accounting for approximately 25% of NHL cases. One of the common subtype of DLBCL is primary DLBCL of the mediastinum. Case report this 65 year old female known to have diabetes and hypertension presented to our emergency department with history of epigastric pain for last 2 h. Her electrocardiogram (ECG) showed right bundle block with left posterior hemi-block representing bi-fasicular block with minimal ST segment depression in leads V4–V6. Her initial routine laboratory results revealed normal renal function, blood counts and liver profile. Her cardiac bio-markers were elevated with Troponin I of 1.22 and CPK of 35. She was admitted by the cardiology team diagnosis of non-ST elevation myocardial infarction (NSTEMI). She was started with usual anti-ischemic. Next morning she had echocardiography which revealed a large mediastinal mass on the antero-lateral aspect of the left ventricle infiltrating the basal lateral and anterior wall. This mass was encasing the origin of the great vessels and also infiltrating the left atrium occluding the Left atrial appendage and left upper pulmonary vein. It was infiltrating the Right ventricular outflow tract causing obstruction to the flow with a gradient of 52 mmHg. Cardiac MRI showed multiple cardiac masses, the largest of which was originating from the anterior mediastinum and going posteriorly then infiltrating RV and within the right ventricular out-flow tract (RVOT) causing significant obstruction. The magnetic resonance characteristics of the intra cardiac and extra cardiac masses were same and with features of central necrosis was highly suggestive of lymphoma. The CT scan of the chest and abdomen showed the same cardiac findings as of cardiac MRI and multiple enlarged thoracic, retroperitoneal, left common iliac lymph nodes. Patient had CT guided Lymph node biopsy from the mediastinal lymph node and was reported as Diffuse Large B-Cell lymphoma of non-germinal center subtype with anaplastic features. Bone marrow biopsy was also performed as well PET oncology to complete staging process. The case was discussed in the multi-disciplinary oncology board and planned for chemotherapy with CHOP with no need for any cardiac intervention at this moment. The care of the patient was transferred to the hematology team with close follow-up by cardiology team. He received the chemotherapy for 4 cycles and had a repeat cardiac MRI which showed the complete resolution of the intra-cardiac mass. Patients with DLBCL typically present with a rapidly enlarging symptomatic mass, most usually nodal enlargement in the neck or abdomen, or, in the case of primary mediastinal large B cell lymphoma, the mediastinum, but may present as a mass lesion anywhere in the body. The prognosis is good as the rate of remission with chemotherapy is good. The cardiac MRI can assist in diagnosis.