The authors discuss the case of a 76-year-old female patient who has been suffering from subacute cutaneous lupus erythematosus since 1983. In 1999 she was diagnosed with systemic lupus erythematosus (SLE) based on her symptoms of malar rash, polyarthritis, leukopenia, autoimmune hemolytic anemia and positive anti-DNA antibody test. For this she received methylprednisolone and cyclophosphamide. After 3 years of remission, symptoms of cutaneous vasculitis appeared in 2004, which transitionally responded to treatment with azathioprin and methylprednisolone. Her cutaneous symptoms, however, progressed quickly along with generalized lymphadenopathy, splenomegaly and thrombocytopenia. Immunohistological evaluation of the lymph node biopsy showed diffuse large B-cell lymphoma. She developed complete remission after treatment with six-cycle R-CHOP (rituximab, and reduced doses of cyclophosphamide, vincristin, adriablastin, methylprednisolone). SLE became inactive and her symptoms of vasculitis resolved. The authors are bringing attention to one of the possible late complications of systemic lupus, and also underscoring that treatment with rituximab (+CHOP) was beneficial not only for the lymphoma but the SLE as well.