Plasmablastic Lymphoma of the Nasopharynx in an HIV-Negative Patient

Abstract

Plasmablastic lymphoma (PBL) is a rare and aggressive subtype of non-Hodgkin's lymphoma. It was originally described to occur predominantly in oral cavity of human immunodeficiency virus (HIV)-positive patients. However, some are known to be associated with other forms of immunosuppression or immunocompetent patients. We report an unusual case of PBL presenting in nasopharynx of an 85-year-old woman without HIV infection. Histopathologic examinations demonstrated a large cell lymphoma with plasmablastic differentiation. Considering morphology, positivity for CD138 and leukocyte common antigen, and focal high ki67 index, PBL was most consistent although Epstein-Barr virus encoded RNA was not detected. Positron emission tomography scan revealed hypermetabolic lesions in the nasopharynx and the right cervical lymph nodes. Marrow involvement was confirmed by biopsy of the iliac crest. According to the Ann Arbor staging system, she was diagnosed as stage IV. After endoscopic removal of the tumor, she completed six cycles of chemotherapy, but expired due to the disease progression.