Although the MYD88 mutation has been investigated in several extranodal DLBCLs (such as primary central nervous system DLBCL, testicular DLBCL, cutaneous DLBCL (leg type), and breast DLBCL), studies on the MYD88 mutation in PBL have been limited, and the clinical significance of the MYD88 mutation has remained unclear. This evidence concerns the gene MYD88 and breast diffuse large B-cell lymphoma.