Oral and extraoral plasmablastic lymphoma: similarities and differences in clinicopathologic characteristics.

Plasmablastic lymphoma (PBL), initially characterized as an aggressive lymphoma arising in the jaw and oral mucosa in HIV-infected patients, was recently reported to occur with extraoral manifestations, heterogeneous histologic findings, and variable association with immunodeficiency states. We reviewed clinical, morphologic, and immunophenotypic features of 13 cases of PBL to determine whether these different subtypes represent distinct morphologic and clinical entities. Two distinct subtypes of PBL were identified and classified as oral and extraoral PBL. The oral PBLs were strongly associated with HIV infection and commonly demonstrated plasmablastic morphologic features without plasmacytic differentiation. Extraoral PBLs tended to occur in patients with underlying non-HIV-related immunosuppression and universally demonstrated plasmacytic differentiation. The patients with oral PBL demonstrated better overall survival compared with patients with extraoral PBL (P = .02). Our findings suggest that PBL with oral and extraoral manifestation represent 2 distinct clinicopathologic entities.