A biopsy of the tumor on the left side of the tongue root was performed, showing CD3 (-), CD20 (+), CD10 (-), Bcl-6 (+), MUM-1 (+), Bcl-2 (50%+), c-Myc (60%+), CD5 (-), CyclinD1 (-), CD56 (-), TIA-1 (-), and Ki-67 (90%+); a pathological diagnosis of diffuse large B-cell lymphoma (DLBCL), non-germinal center B-cell-like (GCB) was made. Here, CD5 is linked to diffuse large B-cell lymphoma.