Primary follicular lymphoma of the prostate

Abstract

Only 5 cases of follicular lymphoma (FL) have been reported in the prostate. A 68-year-old man presented with dysuria. Laboratory data did not indicate malignancy in the prostate with serums PSA of 4.6 ng/ml. Imaging techniques identified no tumors and lympho-adenopathy other than the prostatic enlargement. The patient was clinically diagnosed as prostatic hyperplasia, and trans-urethral resection of prostate (TURP) (65 g) was done. Histologically, the TURP-specimens showed severe nodular proliferation of atypical small lymphocytes consisting of small centrocytic lymphocytes and large centroblastic lymphocytes, the number of the latter being 2/HPF. Immunohistochemically, the tumor cells and nodular areas were positive for CD45, CD20, CD79a, bcl-2, bcl-6, and CD10. They were negative for pan-cytokeratin (AE1/3, CAM5.2), CD3, CD45RO, CD56, PSA, chromogranin-A, synaptophysin, NSE, CD138, CD15, CD30 and cyclin D1. No significant number of plasma cells were seen by immunohistochemistry for light chains and CD138. A pathological diagnosis of primary FL (grade 1) of the prostate was made. No tumors were identified by various imaging techniques, and the prostatic FL was diagnosed as primary. The patient underwent low-dose R-CHOP chemotherapy and focal radiation, probably resulting in complete remission. No recurrence has been found 5 months after the diagnosis.