Objective   To investigate the incidence and clinical features of multiple primary malignant tumors related to renal cell carcinoma.     Methods   The patient history

treatment

and prognosis in 21 cases of multiple primary malignant tumors associated with renal cell carcinoma were analyzed retrospectively.     Results   From December 2004 to December 2007

the incidence rate of multiple primary malignant tumors associated with renal cell carcinoma in our hospital was 6.23% (21/337). In 12 male cases

prostate cancer

colon cancer

esophageal cancer

and non-Hodgkin’s lymphoma were the most common. Occurrence of other primary malignancies before renal cell carcinoma was found in 4 cases

co-occurrence in 3 cases

and post-occurrence in 5 cases. Nine female patients were mainly characterized by breast cancer. Occurrence of other primary malignancies was found in 7 cases

but co-occurrence in 2 cases. The sub-type of renal cell carcinoma belonged to clear cell carcinoma in all patients.     Conclusion   Multiple primary malignant tumors and concurrent renal cell carcinoma are not rare. The treatment of multiple primary malignant tumors related to renal cell carcinoma should be conducted in accordance with the principle of different strategies for different malignancies.