Extra-oral plasmablastic lymphomas in a high HIV endemic area.

Abstract

INTRODUCTION\nPlasmablastic lymphoma (PBL) occurs mainly in immune-compromised individuals, usually secondary to HIV infection. It classically occurs intra-orally but has been described in extra-oral locations.\n\n\nAIM\nTo define the immunophenotype and EBV status in a large single center cohort of extra-oral PBL (EPBL) in South Africa, a high HIV setting.\n\n\nMATERIALS AND METHODS\nThis retrospective study of 45 EPBLs included patients age, gender, race, HIV status and site. Cases were reviewed histologically and classified morphologically as pure plasmablastic or plasmablastic with plasmacytic differentiation; and assessed immunohistochemically with CD45, CD20, CD79a, PAX5, CD138, MUM1/IRF4, BLIMP1, VS38c, Ki-67, BCL6, CD10, CyclinD1 and HHV8 using standard automated procedures. EBV was assessed by chromogenic in-situ hybridization. Tumors were assessed with fluorescence in-situ hybridization MYC break apart probe.\n\n\nRESULTS\nTwenty-seven PBLs showed pure plasmablastic morphology, and 18 showed plasmacytic differentiation. Male:female ratio was 1.5:1. The anus was the favored extra-oral site (31.1%), followed by lymph nodes (15.6%). All 29 patients of known HIV status were HIV positive. The immunohistochemical profile recapitulated that reported for oral and EPBLs in HIV-positive and negative patients. EBV was positive in 92.5% of PBLs. FISH analysis showed MYC rearrangement in 48% of cases… CONCLUSION: This study showed a strong association of EPBLs with HIV and EBV infection, similar to previously described oral PBL. The high EBV association together with other clinico-pathologic parameters and an immunohistochemical profile that includes CD45, CD20, MUM1/IRF4, CD138 and Ki-67 may be used in distinguishing PBL from diffuse large B-cell lymphoma and plasma cell myeloma. This article is protected by copyright. All rights reserved.