Oral solid form of primary effusion lymphoma mimicking plasmablastic lymphoma.

Primary effusion lymphoma (PEL) is a rare large cell lymphoma subtype that usually is associated with human immunodeficiency virus infection. Features facilitating PEL identification are its clinical presentation, cytologic findings, immunophenotypic profile, and particularly, relation to human herpesvirus 8 (HHV8) infection. Uncommonly, PEL may present as a solid form that predominantly involves the distal digestive tract and poses major diagnostic problems, especially when unassociated with body cavity effusions. We herein report the case of an HIV-positive 42-year-old male with synchronous presentation of a pleural cavity PEL and a tongue-based lesion, both displaying plasmablastic features. Demonstration of HHV8 presence in the lingual lesion excluded a plasmablastic lymphoma and established the diagnosis of an oral solid form of PEL. This case illustrates the need for investigating HHV8 in any plasmablastic-looking lymphoma, especially in HIV-infected patients.