Herpesvirus 8–Negative Primary Effusion Lymphoma Associated With Hepatitis C Virus

Abstract

Nador et al. 5 first identified two types of primary effusion lymphoma (PEL) with different etiologic and genetic backgrounds. A striking finding of this report was that the presence of human herpes virus type 8 (HHV8) and the rearrangement of the c-MYC gene appeared to be mutually exclusive molecular events. 5 Thus, we proposed classifying HHV8+c-MYCG and HHV8−c-MYCR as PEL type I and type II respectively. 2 Because the lymphoma cells in our case showed neither HHV8 by polymerase chain reaction nor c-MYC gene rearrangement by cytogenetics or Southern blot analysis, we proposed a third category of PEL—HHV8−c-MYCG, or PEL type III. We considered that the patient reported by Ascoli et al. 1 could belong to either PEL type II or type III. 2 The demonstration of t(8;22)(q24;q11) by cytogenetics and the Burkitt morphology of the lymphoma cells in that patient argue for c-MYC gene involvement. However, it is well recognized that a cytogenetic breakpoint at 8q24 is not always synonymous with a rearranged c-MYC gene. 3,4,6 In the absence of more definitive proof of a c-MYC gene rearrangement, we subclassified tentatively the patient of Ascoli et al. 1 into the type III category. However, if a c-MYC gene rearrangement could be demonstrated by detailed analysis with genomic deoxyribonucleic acid, we would classify the patient as type II. We agree that HHV8− PEL represents a less well-characterized group than HHV8+ PEL, and that there is a need to identify more HHV8− PEL patients to achieve consensus in classifying these lymphomas. The initial report that the presence of HHV8− PEL was associated invariably with rearrangement of the c-MYC gene and Burkitt morphology, and our findings that point to the existence of HHV8−c-MYCG PEL with non-Burkitt morphology, suggests that PEL type III may represent a distinct category of these lymphomas. Ryo Ichinohasama M.D., Ph.D. Ikuo Miura M.D., Ph.D. John F. DeCoteau M.D.