Patient 1 with RA. Neutropenia associated with LGLL and monoclonal IgM gammopathy were diagnosed in 1998. Low-dose methotrexate was given from 1998 to 2001 and then stopped because of agranulocytosis with severe stomatitis. Cyclosporine A and G-CSF were started in 2001 and then discontinued in 2004 because of chronic fever and weight loss attributed to monoclonal IgM progression. The first rituximab infusions were given in 2005 and ensured control of the joint symptoms, a decrease in monoclonal IgM titers, and prolonged complete remission of the leukemia. CsA, cyclosporine A; MTX, methotrexate.