Primary diffuse large B-cell lymphoma of the prostate: A report of two cases with diagnostic considerations.

Primary prostatic lymphomas are extremely unusual neoplasms. Their rarity and nonspecific symptomatology at presentation usually prompt a clinical diagnosis of benign prostatic hyperplasia or chronic prostatitis, leading to significant delay in diagnosis. Clinical examination, serum prostate-specific antigen levels, and transrectal ultrasonography (TRUS) are not of much utility in differential diagnosis, and histological examination is the gold standard. We report two cases of primary non-Hodgkin lymphoma of prostate, diffuse large B-cell type, diagnosed on TRUS-guided prostatic biopsies. Correct diagnosis is of crucial importance as the therapeutic strategy for lymphoma is radically different from that for carcinoma, and early detection of prostatic lymphoma can be potentially curative. Thus, knowledge of this rare entity, inclusion in differential diagnosis of lower urinary tract obstruction, and application of an appropriate immunohistochemical panel are essential so as not to miss this unusual diagnosis and to avoid unnecessary surgery.