BCL2 and diffuse large B-cell lymphoma: However these cases lacked a “starry sky” appearance at low magnification, showed marked nuclear pleomorphism at high magnification (Figure 4D), did not demonstrate a high Ki67 proliferation index (60% and 75%, respectively) and had an abnormal immunophenotype (BCL2+) and, therefore we felt that that the classification as DLBCL, NOS, was appropriate.