Malignant lymphoma is often accompanied by an autoimmune disorder. Here, we describe a 82-year-old woman with pure red cell aplasia (PRCA) complicated with relapsed diffuse large B-cell lymphoma. Primary treatment involving chemotherapy, continuous oral administration of prednisolone and a single infusion of rituximab was unsuccessful for both diseases, but the following treatments with 3 courses of rituximab alone for once a week dramatically improved the PRCA as well as the lymphoma. As PRCA complicated with lymphoma is rare, the ideal therapeutic strategy has not yet been established for it. Rituximab may be a good alternative for treating such cases.
