Systemic CD5-Positive Diffuse Large B-cell Lymphoma Preceded by Intravascular Large B-cell Lymphoma-like Features in the Prostate: A Case Report.

We report a rare case in which CD5-positive diffuse large B-cell lymphoma, not otherwise specified (DLBCL NOS), and CD5-positive intravascular large B-cell lymphoma (IVLBCL) were identified in different samples from the same patient. A 76-year-old man presented with widespread lymphadenopathy and a prostatic mass on imaging. A prostatic biopsy revealed CD5+ DLBCL NOS. Notably, he had undergone transurethral resection of the prostate (TURP) four months prior because of urinary retention. A retrospective histological review of the TURP specimen revealed CD5-positive IVLBCL. This case suggests that DLBCL may initially manifest with an IVLBCL-like growth pattern at an extremely early stage.