Clinicopathological features of HCV-positive splenic diffuse large B cell lymphoma

The hepatitis C virus (HCV) is a single-stranded RNA virus which is thought to be involved in the onset of B cell lymphoma. HCV-positive diffuse large B cell lymphoma (DLBCL) has been reported to clinically manifest in extranodal lesions (e.g., in the liver, spleen, and stomach). Here, we investigated HCV-positive and -negative primary splenic DLBCL (p-spDLBCL) and non-primary splenic DLBCL (ordinary DLBCL). Furthermore, to examine HCV lymphomagenesis, RNA in situ hybridization (ISH), RT-PCR (reverse-transcription polymerase chain reaction), and NS3 immunostaining of HCV viral nonstructural proteins were performed. HCV-positive p-spDLBCL patients presented fewer B symptoms (asymptomatic) and better performance status, with elevated presence of splenic macronodular lesions and more germinal center B cell (GCB) sub-group cases than HCV-negative p-spDLBCL patients. However, HCV-positive ordinary DLBCL patients were found to have more non-GCB sub-group cases than HCV-negative ordinary DLBCL patients. HCV-positive DLBCL patients showed 20.6% (7/34) NS3 positivity, 16.7% (1/6) HCV-RNA in situ positivity, and 22.2% (2/9) detection of HCV-RNA in tumor tissue by RT-PCR. Splenic samples were found to have a higher frequency of HCV detection than lymph node samples, thus suggesting that HCV may be closely related to lymphomagenesis, especially in splenic lymphoma.