Plasmablastic lymphoma (PBL) is an aggressive B-cell neoplasm composed of cells with plasmablastic or immunoblastic morphology and a terminally differentiated B-cell immunophenotype [1]. The cell of origin of this type of lymphoma is thought to be a plasmablast, an activated B cell that has undergone somatic hypermutation and class switching recombination and is in the process of becoming a plasma cell [1]. Genomic profiling has suggested that cases of PBL are closer to diffuse large B-cell lymphoma than they are to plasma cell myeloma [2].

PBL is a rare, representing about 1 % of large B-cell lymphomas and 2 % of human immunodeficiency virus (HIV)-related lymphomas [3,4]. Patients who develop PBL usually have immunodeficiency of various causes, including HIV infection, transplant recipients, patients with autoimmune diseases and older individuals with physiological immunosenescence. PBL is known to be clinically aggressive, and patients are often refractory to standard chemotherapy, with frequent relapses and a poor prognosis. Timely diagnosis with early treatment is needed in the management of PBL patients.

PBL is composed of large cells and a distinctive feature is that this neoplasm has a plasmablastic immunophenotype. In other words, these neoplasms are positive for plasma cell-associated markers, such as CD138 and MUM1/IRF4, and are negative for pan B-cell markers, such as CD20. About 75 % of these neoplasms are positive for Epstein-Barr virus (EBV) infections, most conveniently shown by using in situ hybridization analysis to assess for Epstein-Barr virus encoded RNA (EBER).

PBL was originally described in the oral cavity of HIV infected patients, and the oral cavity remains one of the most common extranodal sites of involvement [5]. However, PBL can involve many other extranodal sites including the gastrointestinal tract, soft tissue, and skin [4]. Lymph node and bone marrow involvement are uncommon [4]. The kidneys are an extremely rare primary site of PBL.

We report a patient without evidence of HIV infection who presented with a large kidney mass involved by an EBV-negative PBL. We also review the literature on PBL, focusing on cases involving the kidneys, and the differential diagnosis of this neoplasm.