Recently, large cohort studies have shown a higher incidence of extranodal disease including central nervous system (CNS) involvement and adverse outcome in patients with CD5+ DLBCL.26, 27 However, involvement of the gastrointestinal tract has been reported to occur less frequently in CD5+ DLBCL than CD5− DLBCL.28 Therefore, the prognostic significance of CD5 positivity in primary iDLBCL has not been well analyzed. Here, CD5 is linked to diffuse large B-cell lymphoma.