發生於攝護腺之惡性淋巴瘤，不論是原發性或繼發性，都是非常罕見的。我們報告一位 74歲男性因急性尿滯留的症狀求醫，進而被診斷出罹患侵犯攝護腺癌之彌散性惡性淋巴瘤。肛門指診發現光滑而有彈性之輕微攝護腺肥大。在良性攝護腺肥大之初步診斷之下，病患接受了經尿道攝護腺刮除術。病理報告發現充滿腫瘤細胞之浸潤。特殊之免疫組織化學染色顯示 CD20為陽性，符合為惡性B 細胞淋巴瘤。全身性檢查發現疾病散佈多區域。背部腫塊切片發現廣泛浸潤中小非典型淋巴細胞，特殊之免疫組織化學染色顯示 CD10 及 CD20 為陽性，診斷為濾泡型淋巴瘤。病患接受了四次的 rituximab, cyclophosphamide, etoposide, vincristine and prednisone
(R-CEOP) 化學治療，但腫瘤很快復發。病患再接受補救性化學治療及主動脈旁腫大之淋巴結的放射治療。由於病情惡化病患沒能完成全程之放射治療，病患於最初診斷後的 9 個月帶病死亡。

Malignant lymphoma of the prostate gland, either primary or secondary, is rare. We report a 74-year-old male who was diagnosed with disseminated lymphoma including involvement of the prostate gland with the initial presentation of urinary retention. Digital rectal examination revealed mildly enlarged prostate gland with smooth and rubbery consistency. He received transurethral resection of the prostate under the impression of benign prostatic hyperplasia. The pathology found diffused infiltration of atypical lymphoid cells infiltration. The immunohistochemical staining
revealed positive for CD20, and consistent with malignant B cell lymphoma. Systemic work-up found that his disease has disseminated many areas. Back mass biopsy showed small to medium atypical lymphoid cells diffused infiltration with immunohistochemical staining for CD3(-), CD5(-), CD10(+), CD20(+), CD23(-), and Cyclin D1(-). The diagnosis of follicular lymphoma was made. The patient received four cycles of chemotherapy with rituximab, cyclophosphamide, etoposide, vincristine and prednisone (R-CEOP). After temporarily partial response, tumor regrowing was noted. Salvage chemotherapy followed by the radiotherapy (RT) to the enlarged paraaortic lymph nodes was given. The patient did not finish the RT course because of exacerbated condition. He died with the disease 9 months after diagnosis.