A 75-Year-Old Female with Dyspnea: An Unusual Presentation of Diffuse Large B-Cell Lymphoma.

Diffuse large B-cell lymphoma (DLBCL) is a common variant of non-Hodgkin lymphoma (NHL). It usually presents as a rapidly enlarging mass. Numerous presentations involving the gastrointestinal tract, bone, and the central nervous system have been reported in the past including both primary and secondary involvement of organs. A 75-year-old lady was found to have a pericardial effusion while being evaluated for shortness of breath. A therapeutic pericardial tap was positive for pan-B cell markers. The patient's detailed radiological studies failed to show a primary tumor. We report this unusual presentation of DLBCL as a pericardial effusion without a primary source in a patient with mild shortness of breath.