Coexisting avascular lesions and renal cell carcinoma.

An analysis of 99 cases of coexisting renal avascular lesions and renal cell carcinoma suggests that: (1) a direct pathogenetic relationship exists in the majority; (2) the cyst-related carcinoma tends to occur at an earlier age; (3) angiography alone is not reliable for the diagnosis of an apparently benign renal mass, and (4) individuals with polycystic kidneys share at least an equal risk of renal carcinoma as the general population.