HHV8-negative effusion based lymphoma: a series of 17 cases at a single institution.

INTRODUCTION

Human herpesvirus 8-positive (HHV8+) primary effusion lymphoma is a well-recognized clinicopathologic entity. In contrast, HHV8-negative (HHV8-) effusion-based lymphoma (EBL) is incompletely characterized and under-recognized. We describe 17 cases of HHV8- EBL at our institution.

MATERIALS AND METHODS

Cytology and available immunohistochemistry and cytogenetics were reviewed. Patient demographics, history, and outcome were obtained from medical records.

RESULTS

The effusions were pleural (n = 9; 53%), peritoneal (n = 4; 24%), pericardial (n = 3; 18%), and pleural and pericardial (n = 1; 6%). Fifteen cases (88%) were CD20+ and 15 had sufficient information for classification by Hans algorithm (CD10, BCL6, MUM1): 11 (73%) nongerminal center and 4 (27%) germinal center phenotype. Epstein-Barr virus in situ hybridization was negative in 16 cases (94%). Three of 14 cases were MYC+ by immunohistochemistry. Fluorescence in situ hybridization, performed on 5 of the 17 cases, showed a MYC rearrangement in 1 case and a BCL6 rearrangement in 2 cases. Most patients were elderly (median age 86 years) and female (82%). Human immunodeficiency virus testing results, available in 4 patients, were negative. Seven (41%), including 1 of 2 heart transplant recipients, had congestive heart failure. Follow-up (5 days to 12 years) was available for 16 patients including 4 who survived ≥8 years. Only 1 of the 8 known deaths was clinically attributed to lymphoma.

CONCLUSIONS

HHV8- lymphomas that occur in body cavity effusions without detectable lymphomatous masses are usually composed of large CD20+ lymphoid or lymphoplasmacytoid cells. In contrast to HHV8+ primary effusion lymphoma, patients with HHV8- EBL are usually elderly, lack a documented human immunodeficiency virus-positive history, and have a longer disease specific survival.