PLASMABLASTIC LYMPHOMA AS THE PRESENTING SIGN OF HIV INFECTION

Plasmablastic lymphoma (PBL) is an aggressive lymphoma that can present both diagnostic and therapeutic challenges. Currently considered a variant of diffuse large B-cell lymphoma by the WHO, it demonstrates overlapping phenotypic features with plasma cell myeloma and other neoplasms exhibiting plasmablastic morphology. The majority of cases arise in immunocompromised patients and a predilection for oral involvement is seen. The underlying etiology is poorly understood, although roles for the MYC oncogene and Epstein-Barr virus are likely. Our patient was a 33-year-old male who presented for evaluation of a left maxillary gingival mass. He reported a one-month history of increasing pain and mobility of the adjacent teeth. Radiographic examination revealed an ill-defined radiolucency located apical to the left lateral incisor and extending to the midline. On questioning, the patient disclosed that he had undergone a routine physical examination one month prior with no abnormal findings. A biopsy was performed which showed sheets of large atypical cells interspersed with tingible body macrophages in a starry sky pattern. The tumor cells were positive for CD10, CD38, CD138, MUM-1, and HLA-DR, and negative for B-cell markers. Kappa and Lambda were negative and Ki-67 expression of >90% was noted. In situ hybridization for EBER was positive and genomic studies confirmed MYC gene rearrangement associated with an additional copy of IgH. A final diagnosis of plasmablastic lymphoma was rendered. Over the course of his oncologic work-up, it was discovered that he was HIV-positive. Despite multiple cycles of chemotherapy, the patient developed pelvic involvement six months later and died one year after his initial diagnosis. PBL is a rare lymphoma that pursues an aggressive clinical course characterized by frequent relapses and high rates of disease progression. No universal treatment protocol exists, although more intensive chemotherapy is currently favored. Bortezomib-based regimens show promise in both frontline and relapsed settings.