CD20 is associated with a small mature plasma cell morphology and t(11;14) in multiple myeloma

CD20 has been reinvestigate.d in 66 patients with multiple myeloma (MM); Twelve of the patients (18%) expressed CD20, including 5 of 50 patients at diagnosis presenting 100% CD20(+) cells. Seven (58%) of 12 CD20(+) patients with MM had a small mature plasma cell morphology as opposed to 4 (7%) of 54 with CD20(-) MM (P =.0001). Of note, 10 (83%) of 12 patients With CD20(+) MM had t(11;14) as opposed to 5 of 54 (9%) CD20(-) patients (P <.001). All the patients with 100% CD20(+) cells presented with t(11;14) and 4 of 5 with a small mature plasma cell morphology. Thus, 66% of the patients With t(11;14) expressed CD2b, Whereas only 4% of the 51 patients lacking such translocation expressed CD20 (P<0001). In conclusion, CD20 expression is associated with small mature plasma cell morphology and with t(11;14) in patients with MM.