Introduction: This review is aimed at defining the frequency, anatomical and clinical presentation, pathogenesis, predictive factors and treatment of malignant lymphoproliferative diseases occurring in the course of Sjögren's syndrome.
Current knowledge and key points: The frequency of non-Hodgkin's lymphoma (NHL) is estimated to be about 7%. Other malignant lymphoproliferative diseases (Waldenstrom's macroglobulinemia, multiple myeloma, Hodgkin's disease) are rarely observed. NHL is most frequently extranodal (affecting the salivary glands, stomach, lung, etc) in low grade malignancy (MALT lymphoma [mucosa associated lymphoid tissue]). The pathogenesis of NHL in Sjögren's syndrome is a multi-step process, including B cell monoclonal proliferation, oncogenic and/or infectious agents, and/or cytokines. Various predictive factors such as persistent enlargment of parotid glands, adenopathy, splenomegaly, mixed cryoglobulinemia, monoclonal gammopathy, suggest potential lymphoma evolution. The treatment of Sjögren's syndrome-associated NHL depends on the type of lymphoma. Moreover, in patients with low-grade lymphoma therapeutical strategies varies according to the stage and evolution of the disease.
Future prospects and projects: Future prospective longitudinal studies should permit to define the best criteria for malignant transformation and to improve therapeutical strategies.