Cardiac Tamponade Due to Diffuse Large B-cell Lymphoma/Plasmablastic Lymphoma in an Immunocompetent Patient.

Plasmablastic lymphoma (PBL) is a rare and aggressive subtype of diffuse large B-cell lymphoma, present predominantly in immunosuppressed individuals, particularly with human immunodeficiency virus (HIV) or Epstein-Barr virus (EBV) infection. Although the incidence of HIV-positive vs HIV-negative PBL is unknown, a literature review vastly associates it with immunocompromised status. Primarily seen in the male population in approximately 75% of reported cases, PBL has a well-established clinical presentation of one or two extra-nodal masses, generally in the oral cavity and gastrointestinal tract. We present a case of a 93-year-old female without any evidence of HIV infection or extra-nodal mass who presented with shortness of breath due to a large malignant pericardial effusion that evolved into a tamponade. Plasmablastic lymphoma is one of the few reported in HIV-negative individuals, and its unique presentation as a pericardial effusion without extranodal mass makes its suspicion less apparent. However, awareness of this entity, comprehensive immunohistochemistry, and most importantly, correlation with clinical presentation is the cornerstone to establishing a correct diagnosis.