Intervascular Large B-cell Lymphoma with Severe Anemia and a High-titer of Cold Agglutinin.

A 79-year-old woman was admitted to our hospital with a persistent fever, malaise, and anemia requiring frequent transfusions. A peripheral blood smear revealed erythrocyte agglutination and a high titer of cold agglutinins. Imaging examination revealed pulmonary emboli and multiple subacute cerebral infarctions. Despite the absence of lymphadenopathy or splenomegaly, the diagnosis of intravascular large B-cell lymphoma (IVLBCL) was confirmed through random skin biopsies. Immunochemotherapy successfully induced remission of her fever and anemia with normalization of her cold agglutinin titer. This case highlights that cold agglutinin syndrome can be associated with aggressive lymphomas, including IVLBCL.