Background High-grade B-cell lymphomas (HGBLs), with c-Myc, Bcl2, and/or Bcl6 rearrangement, are aggressive neoplasms with poor clinical outcomes. Cyclin D1 is a proto-oncogene that is generally expressed by mantle cell lymphoma, its variants, and many other neoplasms. Aim The aim of this study is to investigate the expression and frequency of cyclin D1 in HGBL and its association with double expressor and triple expressor lymphomas. A few pieces of research have been reported on the expression of cyclin D1 in triple-hit lymphoma, renaming it quadruple-hit lymphoma. In the present study, we a...