[The 503rd case: monoclonal IgM immunoglobulinemia, severe anemia with recurrent fever].

A 42-year-old woman was diagnosed with Waldenström macroglobulinemia (WM) with fatigue, anemia, and monoclonal IgM immunoglobulinemia 6 years prior. She experienced persistent severe anemia with only transient remission after initial chemotherapy and after multiple chemotherapy regimens and immunosuppressive therapies, which were accompanied by recurrent high fever with severe complications including urinary infection, sepsis and shock, rectal perforation, and severe obstructive jaundice. The anemia was diagnosed as warm autoimmune hemolytic anemia and aplastic crisis with inflammation anemia. She received ibrutinib 140 mg once a day, and her hemoglobin levels returned to normal. WM remained stable in very good partial remission with no infection.