MS4A1 and splenic marginal zone lymphoma: Some studies reported that 6% to 21% of SMZL patients had been described to exist the MYD88L265P mutation, which was thought to increase the occurrence of plasmocytic differentiation.[7] Owing to lack of the spleen specimen, the patient met the second minimum diagnostic criteria for SMZL including an increased proportion of lymphocytes in peripheral blood and bone marrow, a 1-point chronic lymphocytic leukemia score, and characteristic CD20 + cells with intrasinusoidal infiltration.