Primary renal non-Hodgkin's lymphoma - a difficult differential diagnosis

Abstract

Introduction: Primary renal lymphoma (PRL) as a clinical entity is not undisputed because the kidneys do not contain lymphatic tissue and the mechanism of development of PRLs is unclear. Most of the few cases reported showed rapid systemic progression and a poor prognosis. Although there are no clearly defined diagnostic criteria for renal lymphomas, abdominal and thoracic computed tomography as well as renal and bone marrow biopsy are recommended. 3 cases of renal lymphoma are reported and their diagnosis and management discussed.

Case reports: Between 1996 and 2001, 3 male patients with renal lymphoma were diagnosed and treated at our institution. In patient No. 1, because of persisting macroscopic hematuria a bilateral PRL was diagnosed by renal biopsy, without any detectable lesions on CT imaging. Patient No. 2 presented with a large renal mass which, on biopsy, was diagnosed as a lymphoma. Patient No. 3 showed lymphoma on renal biopsy and bone marrow involvement. All 3 patients were treated with systemic chemotherapy which resulted in death of disease in 2 patients and a complete remission in 1 patient after adjuvant radiotherapy and nephrectomy.

Conclusion: PRL represents a rare entity which must nevertheless be considered in cases of unusual renal masses or otherwise unexplained renal symptoms. If diagnosed early, cure is possible, and multimodal treatment should be considered.