Abstract
BACKGROUND: Cardiac lymphoma is a rare disease that can present in various ways. Additionally, atypical clinical presentation makes the diagnosis even more challenging. The most common type of cardiac lymphoma is diffuse large B-cell lymphoma. With chemotherapy, the median survival rate can be up to 2 years. In this report, we focus on the diagnostic approach and differential diagnosis. CASE SUMMARY: A 56-year-old patient presented with complete heart block and B-symptoms. Implantation of a pacemaker (PM) was initially deferred due to a junctional rhythm (50 b.p.m.). Echocardiography showed thickening of the left heart with small pericardial effusion. For better visualization of the extent and infiltration cardiac magnetic resonance imaging and computer tomography (CT) were performed. In addition to the cardiac mass, enlarged mediastinal lymph nodes were found on staging CT scan, prompting a transbronchial biopsy. Histology revealed diffuse large B-cell non-Hodgkin lymphoma. The patient was referred to a hospital with a Hemato-oncology Department for initiation of chemotherapy. DISCUSSION: Cardiac lymphoma can be a rare cause of complete heart block. Prior to PM implantation, basic echocardiography is important. In rare conditions like cardiac lymphoma, multimodal imaging, and interdisciplinary decision-making are crucial for management. In the future, lead-less pacemakers could be a safe and effective option for oncology patients.