Clinicopathologic characteristics of lymphoproliferative disorders involving the kidney.

Objective: Lymphoproliferative disorders can involve the kidney, which is associated with a worse prognosis. The objective of this study was to review the clinical and histologic characteristics of patients with lymphoproliferative disorders involving the kidneys.

Methods: Cases with lymphoproliferative disorders showing renal involvement were retrieved from the institutional pathology database for the past 20 years. Data regarding patient demographics, clinical presentations, lymphoma subtypes, history of lymphoma, treatments received, chemotherapy regimens, and patient outcomes were extracted.

Results: The cohort included 48 cases of non-Hodgkin lymphoma with renal involvement, comprising 35 men and 13 women, with a median age of 71.5 years. Most lymphomas were mature B-cell neoplasms, accounting for 42 (87.5%) cases, with diffuse large B-cell lymphoma as the leading subtype in 18 (42.9%) cases. A renal mass was the initial presentation in 33 (68.8%) patients, while the remaining 15 (31.2%) had medical renal complications. Approximately half of the renal mass cases were de novo aggressive lymphomas, while most with renal complications had systemic involvement of previously diagnosed low-grade lymphomas. Chemotherapy, frequently R-CHOP (rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisone), was the primary treatment. Patients with a kidney mass tended to show a worse prognosis than those with medical renal complications, but statistical significance was not reached (P = .347).

Conclusions: The study demonstrates that renal mass is a crucial presentation of lymphoma, in some cases even without history, highlighting the importance of renal biopsy to triage patients for proper treatment and avoid unnecessary nephrectomy.