Cytological Diagnosis of Plasmablastic Lymphoma Involving the Parotid Gland: A Case Report with Review of the Literature

Plasmablastic lymphoma (PBL) is a rare subtype of non-Hodgkin's lymphoma that is associated with acquired immunodeficiency syndrome (AIDS), characterized by its association with Epstein-Barr virus (EBV), aggressive nature, and plasmacytic/plasmablastic differentiation. PBL remains a therapeutic and diagnostic challenge. Diagnosis of PBL by fine-needle aspiration cytology (FNAC) is reported infrequently. We herein describe the cytodiagnosis of a rare case of HIV-negative PBL in a 58-year-old man without EBV infection presented by parotid swelling. The current case study highlights the cytomorphologic features that may help to distinguish PBL from other mimics. However, although the cytomorphologic features may suggest PBL, a definitive diagnosis requires additional studies including tissue biopsy and immunohistochemistry, in addition to biochemical investigations and radiological workup to establish the diagnosis and exclude similar conditions. In conclusion, FNAC is a very useful, simple, rapid and reliable procedure for diagnosis of the lymphoma. FNAC provided the earliest clue to diagnosis of PBL, which was later confirmed by tissue biopsy.