Oral and extraoral plasmablastic lymphoma: Similarities and differences in clinicopathological characteristics.

Abstract

e18539 Background: Plasmablastic lymphoma (PBL) was initially characterized as an aggressive subtype of NHL most frequently arising in the jaw and oral cavity in patients with HIV infection, accounting for 3% of all NHL in this patient population. Recent reports have described patients with PBL presenting with extraoral manifestations, heterogeneity in histologic findings, and variable association with immunodeficiency states. Methods: We reviewed the clinical, laboratory, morphological and immunophenotypic features of 16 cases of PBL seen at the University of Miami to determine whether these different subtypes represent distinct morphological and clinical entities. Results: Based on clinical presentation, two distinct subtypes of PBL were identified and classified as oral (n=7) and extraoral (n=9) PBL. Median patient age was 42.5 (range 4-73) with overall slight male predominance (9:7, ratio 1.3:1). The majority of patients presented with stage III or IV disease. Oral PBL was strongly associated with HIV infection and commonly demonstrated plasmablastic morphology without plasmacytic differentiation. Extraoral PBL involved bones, bone marrow, lymph nodes, nasopharynx, central nervous system, terminal ileum and cecum and tended to occur in patients with underlying non-HIV-related immunosuppression and universally demonstrated plasmacytic differentiation. Treatment was not standardized and included different combination chemotherapy regimens and radiotherapy. After a median follow-up of 16 months, eight of 14 treated patients have died and six are alive (four in remission and two with active disease). The median survival of all patients was 5.5 months (range 2-48). Patients with oral PBL demonstrated better overall survival (OS) compared to those with extraoral PBL (p=0.04). Conclusions: Our findings suggest that PBL with oral and extraoral presentations represent two distinct clinicopathologic entities. No significant financial relationships to disclose.