Kaposi sarcoma herpesvirus/human herpesvirus-8–negative effusion-based lymphoma: Report of 3 cases and review of the literature

Authors

  • Jingnan Xiao MD, PhD,

    1. Department of Pathology and Laboratory Medicine, University of Wisconsin School of Medicine and Public Health, Madison, Wisconsin
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  • Suzanne M. Selvaggi MD,

    1. Department of Pathology and Laboratory Medicine, University of Wisconsin School of Medicine and Public Health, Madison, Wisconsin
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  • Catherine P. Leith MD,

    1. Department of Pathology and Laboratory Medicine, University of Wisconsin School of Medicine and Public Health, Madison, Wisconsin
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  • Sean A Fitzgerald MD,

    1. Department of Pathology and Laboratory Medicine, University of Wisconsin School of Medicine and Public Health, Madison, Wisconsin
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  • Jimmie Stewart III MD

    Corresponding author
    1. Department of Pathology and Laboratory Medicine, University of Wisconsin School of Medicine and Public Health, Madison, Wisconsin
    • Corresponding author: Jimmie Stewart, III, MD, Cytopathology Laboratory/D4-207b, University of Wisconsin Hospital and Clinics, 600 Highland Avenue, Madison, WI 53792; Fax: (608) 263-6453; jj.stewart@hosp.wisc.edu

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Abstract

BACKGROUND

Primary effusion lymphoma (PEL) is a rare subtype of large B-cell lymphoma that arises in body cavities without detectable tumor masses. PEL is universally associated with Kaposi sarcoma herpesvirus (KSHV)/human herpesvirus-8 (HHV8). Despite overlapping features, KSHV/HHV8-negative effusion-based lymphoma is a distinct entity from PEL. To date, 52 cases have been reported. The authors report 3 additional cases received in their laboratory from 2007 to 2012.

METHODS

Clinical data, cytomorphologic features, and immunophenotypic features of the 3 cases were described and compared with those reported in the literature.

RESULTS

The cells in HHV8-negative effusion lymphoma commonly revealed large cell, immunoblastic morphology and B-cell immunophenotype. The 3 cases demonstrated cytomorphologic and immunophenotypic variability. Cytomorphologically, 1 case contained large, highly atypical cells with a moderate amount of cytoplasm, round nucleus, coarsely granular chromatin, and a single macronucleolus. The other 2 cases had medium to large atypical cells with high nuclear-to-cytoplasmic ratios, slightly irregular to cleaved nuclei, and multiple conspicuous nucleoli. One case had a null phenotype with aberrant cytokeratin expression. B-cell phenotype was established by clonal immunoglobulin heavy-chain rearrangement using polymerase chain reaction, whereas the other 2 cases demonstrated a B-cell phenotype by flow cytometry and immunohistochemical staining. All 3 cases were negative for both HHV8 and Epstein-Barr virus.

CONCLUSIONS

HHV8-negative effusion lymphoma exhibits clinical, cytomorphologic, and immunophenotypic variability. Cases with a null-phenotype can be particularly challenging. When effusion lymphoma is suspected, ancillary tests are helpful. Moreover, HHV8 detection is critical in differentiating PEL and HHV8-negative effusion lymphoma, because they have overlapping features yet different prognoses. Cancer (Cancer Cytopathol) 2013;121:661–9. © 2013 American Cancer Society.

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