Orbital Plasmablastic Lymphoma—Comparison of a Newly Reported Entity with Diffuse Large B-cell Lymphoma of the Orbit

Abstract

Objectives: To describe two cases of orbital plasmablastic lymphoma (PBL), a recently defined aggressive large-cell lymphoma with a plasmacytic immunophenotype, typically occurring in the oral cavity of HIV+ patients. To compare their presentation, management, immunohistochemistry and prognosis with orbital diffuse large B-cell lymphoma (DLBCL).Design: Consecutive, comparative case series of patients presenting to a specialist orbital service with histologically proven PBL or DLBCL.Results: Two cases of PBL and 14 cases of DLBCL were identified. The former were 40–49-year-old men, one HIV+, presenting with marked orbital/sinonasal tumour without oral involvement. Both tumours were negative for B-cell markers (CD20, CD79a), showed a plasmacytic immunophenotype (positive for CD 138, Vs38c), and displayed a Ki67 index of 100%. Despite chemotherapy, both patients died within 1 year. Of the 14 patients with DLBCL, 57% were female, mean age 65 yrs, and none were immunocompromised. Only 7 (50%) had sinus involvement and 3 (21%) had prior systemic lymphoma. All were positive for B-cell markers, with a Ki67 index of 55%–80%. None died within 1 year of diagnosis.Conclusions: PBL can present in the orbit and is more aggressive than DLBCL. It must be considered in the differential of orbital large-cell lymphoid tumours showing plasmablastic morphology or immunophenotype.