Renal parenchymal tumors and lymphoma in the same patient: case series and review of the literature.

We reviewed the incidence of diagnosis of renal cell carcinoma and lymphoma in the same patient and analyzed the characteristics of this association. Nine patients in 4 years had the diagnosis of renal cell carcinoma (RCC) and lymphoma, including 2 with Hodgkin disease, 1 with chronic lymphocytic leukemia (CLL), and 3 each with low-grade follicular and intermediate-grade non-Hodgkin lymphoma (NHL). In SEER data, the observed/expected (O/E) ratio of NHL and RCC is 1.86 to 2.07. In our series, 2 patients were diagnosed with NHL after the diagnosis of RCC, 1 was diagnosed concurrently, and in the other 6, lymphoma preceded diagnosis of RCC. In reviews of second malignancies following treatment of Hodgkin disease, RCC is less common (O/E 1.5, with 1/3 being transitional cell carcinoma and 2/3 being adenocarcinoma). We report 2 cases with Hodgkin disease preceding RCC, and in both, Hodgkin disease occurred as an adult. There is a male predominance for patients with both diagnoses, which is greater than the male predominance for either RCC or NHL alone (2.2 vs. 2.0 vs. 1.2). There is an increased likelihood of the lymphoma being extranodal. There is an increased association of RCC and NHL more often among male patients, and often with extranodal lymphoma. Potential common etiological factors include prior treatment for malignancy, genetic predisposition, environmental factors, including a search for viral sequences, and possible immune dysregulation generating the lymphoma and subsequently leading to solid tumors such as RCC or melanoma. Copyright 2006 Wiley-Liss, Inc.