An increased prevalence of hematologic malignancies is often described in patients with Sjögren's syndrome (SS). Viruses have been proposed as possible etiologic or triggering agents of systemic autoimmune diseases (SADs), with hepatitis C virus (HCV) being one of the viruses most frequently associated with autoimmune features and with systemic autoimmune diseases such as mixed cryoglobulinemia or SS. Moreover, the association between HCV infection and hematologic malignancies, mainly non-Hodgkin's lymphoma (NHL), is supported by several studies. For these reasons, the recognized association of specific systemic autoimmune diseases (mainly SS and mixed cryoglobulinemia) with HCV infection, added to the possible evolution of any one of these entities into a B-cell NHL, suggests the possibility of a close relationship among SS, HCV and B-cell lymphoproliferative disorders, especially in patients with type II mixed cryoglobulinemia.