Primary Prostatic Diffuse Large B-Cell Lymphoma: A Case Report and Literature Review

Abstract

Introduction: Primary lymphomas of the prostate are globally rare, representing <0.1% of all prostatic neoplasms. Their rarity and non-specific symptomatology at presentation usually prompt a clinical diagnosis of benign prostatic hyperplasia or chronic prostatitis, leading to significant delay in diagnosis.

Case description: A 32-year-old man presented to our clinic with complaints of difficult urination and perineal pain. An enlarged, hard and nodular prostate was palpable on digital rectal examination. Needle biopsy of the prostate was performed, which revealed diffuse large B-cell non-Hodgkin's lymphoma by immunohistochemical studies. Computed tomography (CT) scan showed a large pelvic mass arising from prostate encasing ureters with bilateral hydronephroureter. No abnormal finding was seen on abdominal CT scan and bone marrow biopsy. Therefore, the disease was classified into the clinical stage IAXE according to the Ann Arbor's criteria. The patient achieved complete response to six cycles of rituximab plus cyclophosphamide, doxorubicin, vincristine and prednisone chemotherapy with the central nervous system prophylaxis. He remained disease free, until 36 months after the end of chemotherapy.

Practical implications: According to the literature, the treatment and prognosis of primary lymphoma of the prostate are the same as that of other nodal lymphomas. The rituximab-based regimen should be considered in the management of prostatic diffuse large B-cell lymphoma.

Keywords: Diffuse large B-cell lymphoma; primary lymphomas; prostate.

Figure 1

Prostatic core biopsy showing diffuse infiltrate of discohesive cells, cells are medium to large sized with abundant cytoplasm, vesicular nuclei and distinct nucleoli. No gland formation is present

Figure 2

Prostatic core biopsy showing positive staining for cluster differentiation 45 (CD 45) (leucocytes common antigen)

Figure 3

Prostatic core biopsy showing positive staining for cluster differentiation 20 (CD 20)

Figure 4

Prostatic core biopsy showing positive staining for cluster differentiation 10 (CD 10)

Figure 5

Pre-treatment axial computed tomography scan image showing large heterogeneous mass (prostate) with internal necrosis causing mass effect on bladder and rectum

Figure 6

Post-treatment axial computed tomography image showing significant interval reduction in primary disease

Figure 7

Post-treatment positron emission tomography image showing significant interval reduction at the primary site without any avid metabolic disease correlating with complete metabolic response