[Primary Follicular Lymphoma of the Prostate Diagnosed after Robotic-Assisted Laparoscopic Radical Prostatectomy : A Case Report and Review of the Literature].

Primary follicular lymphoma of the prostate is extremely rare, with this case representing only the 13th reported in the English literature. This report includes a review of the literature and details of a case in a 75-year-old male with concurrent primary follicular lymphoma and adenocarcinoma of the prostate. The patient was referred to our department due to prostate enlargement observed on CT and complaints of a decreased urinary stream. His PSA level was elevated at 8.9 ng/ml. MRI showed a PI-RADS category 4 lesion in the right peripheral zone of the prostate, with an estimated prostate volume of 60 ml. A transrectal prostate biopsy identified adenocarcinoma in two cores from the right base and one from the left apex, leading to a diagnosis of prostate cancer cT2aN0M0. Subsequently, the patient underwent robotic-assisted laparoscopic radical prostatectomy. Pathological findings confirmed adenocarcinoma in the right and left lobes (pT2a, pN0, EPE0, SV0, LVl1, RM0) and identified concurrent primary follicular lymphoma within the anterior fibromuscular stroma, which was positive for CD20, CD10 and Bcl-2. A complete clinical investigation, including an 18F-fluorodeoxyglucose positron emission tomography scan and bone marrow biopsy, revealed no involvement of other sites, and the patient was ultimately diagnosed with Ann Arbor stage IE lymphoma. No additional treatment was administered, and the patient has been followed up regularly. At six months postoperatively, there was no evidence of recurrence of either prostate cancer or lymphoma.