FCER2 and diffuse large B-cell lymphoma: Immunostaining of the DLBCL cells showed CD20, CD79a, CD5, and BCL2 positivity, CD10, CD15, CD23, CD30, BCL6, and cyclin D1 negativity, and a Ki-67 labelling index of 70%, leading to the diagnosis of DLBCL (Figure 4).