Concomitant renal cell carcinoma and lymphoid malignancies: a case series of five patients and review of the literature.

Appearance of non-Hodgkin's lymphomas (NHL) and renal cell carcinoma (RCC) in same person has been reported in the literature. There is a higher-than-expected incidence of co-occurrence of these neoplastic disorders. The cause for this association remains speculative. Two epidemiological studies have shown that the observed-to-expected ratio for occurrence of RCC in NHL patients were 1.86 to 2.67. We herein describe five patients with both RCC and lymphoid malignancies, and reviewed possible explanations for the association. In three of the five patients, RCC was diagnosed during lymphoproliferative disease work-up, and remaining two cases had been diagnosed with chronic lymphocytic leukemia 1 and 5 years prior to RCC. All RCC cases were detected during staging of the primary tumor, usually by CT scan and/or ultrasound. Our data are in correlation with the literature that there is an increased association of RCC and NHL more often among male patients, and that the lymphoproliferative disease often presents with extranodal involvement. The specialists should be alerted for this possibility when evaluating patients at diagnosis or during follow-up.