The absence of plasmacytoid cells, the presence of plasma cells predominantly outside the nodular lymphoid infiltrates, IGHV4-34 restriction and absence of MYD88 L265P mutation strongly suggest that cold agglutinin-associated lymphoproliferative disease is a distinct entity that is different from lymphoplasmacytic lymphoma.
The IGHV4-34 gene was most frequently expressed in chronic lymphocytic leukemia (27.5%), whereas it was rarely found in leukemic chronic lymphoproliferative disorders (7.7%, P = 0.005).