Introduction: Non-Hodgkin lymphoma is the seventh most common cancer in the United States. It may involve any extranodal organ, although involvement of the genitourinary (GU) tract accounts for <5% of all primary extranodal lymphomas. Published GU lymphoma literature is currently limited to small case series and case reports. The last substantial American series was published in 2009. Our objective was to characterize cases of GU lymphoma from our institution based on organ involved and to review relevant literature.
Patients and Methods: After institutional review board approval, we retrospectively reviewed medical records of patients diagnosed with lymphoma involving the GU organs from 1995 through 2015. Patients with obstructive uropathy from retroperitoneal adenopathy without parenchymal involvement of a GU organ were excluded. We classified extranodal GU lymphomas as primary or secondary, based on involvement of other organs and distant lymphadenopathy.
Results: Thirty-six patients had lymphoid neoplasms involving the kidney, ureters, bladder, testis, penile skin, or prostate in our health system during the study period. Of these, 15 (41.6%) were primary. Most patients initially sought consultation for GU-related symptoms, such as bladder obstruction, hematuria, testicular mass, or abdominal pain. Histological subtypes and flow cytometry findings varied broadly.
Conclusion: Our series reports site-specific outcomes data and adds detail to findings from other published series. Although GU lymphomas are rare, our series confirms prior studies demonstrating presentation in urologic organs. They should be considered in the differential diagnosis in all patients, especially those with unusual findings on examination, cystoscopy, or computed tomography scan.