title: EBV-associated but HHV8-unrelated double-hit effusion-based lymphoma.
abstract: Effusion-based lymphoma is a rare and unique type of large B-cell lymphoma presenting in effusion without a mass lesion. It shares many clinicopathological features with primary effusion lymphoma (PEL), but is distinct from PEL by the absence of HHV8 association. Double hit lymphoma (DHL) is an aggressive B-cell lymphoma, defined by concurrent rearrangement of MYC and BCL2 or BCL6. DHL often presents as lymphadenopathy or an extranodal mass, but rarely occurs in effusion. Here we report a 61-year-old male with alcoholic cirrhosis presenting as massive ascites and left pleural effusion. He has no HIV, HBV or HCV infection and no mass lesion by CT scans. Cytology of both pleural effusion and ascites show large lymphoma cells with plasmablastic morphology characterized by pleomorphic and eccentric nuclei, prominent nucleoli and frequent mitoses. Immunohistochemical study with cell block shows that the lymphoma cells express plasma cell-related markers (CD138, MUM-1 and EMA), but not CD3, CD30, CD45, B-cell markers (CD19, CD20, CD79a, and PAX5), HHV8, ALK or cytokeratin. EBER is positive in most lymphoma cells. Fluorescence in situ hybridization reveals rearrangement at the IGH, BCL2, and MYC loci, but not at BCL6. It is diagnosed as an EBV-associated but HHV8-unrelated double hit effusion-based lymphoma with plasmablastic features. The patient passed away soon after diagnosis without chemotherapy. This is the first reported case of double-hit effusion-based lymphoma with MYC and BCL2 rearrangement. This case illustrates the importance of integrating clinical, cytological, immunophenotypical, and molecular findings to reach a correct diagnosis. Diagn. Cytopathol. 2017;45:257-261. © 2016 Wiley Periodicals, Inc.
authors.affiliation: Department of Pathology, Shuang-Ho Hospital, Taipei Medical University, New Taipei City, Taiwan.
authors.forename: Bo-Jung
authors.initials: BJ
authors.lastname: Chen
authors.affiliation: Department of Radiology, Shuang-Ho Hospital, Taipei Medical University, New Taipei City, Taiwan.
authors.forename: David Yen-Ting
authors.initials: DY
authors.lastname: Chen
authors.affiliation: Department of Pathology, Chi-Mei Medical Center, Tainan, Taiwan.
authors.forename: Chun-Chi
authors.initials: CC
authors.lastname: Kuo
authors.affiliation: Department of Pathology, Chi-Mei Medical Center, Tainan, Taiwan.|Department of Pathology, Taipei Medical University, Taipei, Taiwan.|Department of Pathology, National Taiwan University, Taipei, Taiwan.
authors.forename: Shih-Sung
authors.initials: SS
authors.lastname: Chuang
mesh_terms: D020031:Epstein-Barr Virus Infections / Q000175:diagnosis*; D017809:Fatal Outcome; D019288:Herpesvirus 8, Human; D006801:Humans; D008297:Male; D008875:Middle Aged; D000069293:Plasmablastic Lymphoma / Q000175:diagnosis* / Q000821:virology; D016066:Pleural Effusion, Malignant / Q000175:diagnosis* / Q000821:virology
keywords: Epstein-Barr virus; double hit lymphoma; effusion-based lymphoma; human herpesvirus-8/Kaposi's-sarcoma associated herpes virus; primary effusion lymphoma