[Clinical study of renal cell carcinoma as incidental finding].

Reports on renal cell carcinoma (RCC) as an incidental finding have been increasing in recent years as the imaging modalities including ultrasonography (US) and computerized tomography (CT) scan have gained popularity in clinical medicine. Because effective treatment in RCC is only surgical removal of the involved kidney even at present, it is imperative for urologists to find and to diagnose the RCC in early stage. Whether RCC found incidentally is in early stage cancer is not determined at present. To determine if the RCC found incidentally is in early stage cancer and if the survival rate is better than that of the RCC found with symptoms, we undertook the following study. Between December 1972 and March 1990, 65 patients with RCC were registered at the Department of Urology, Teikyo University Hospital. Of 65 patients 20 with RCC as an incidental finding were subjected to this study. 34 patients with RCC found with symptoms including hematuria were subjected to control group. Causes of the diagnosis in 20 patients included workup for non-urological diseases in 11 patients (55.0%), workup for urological disease other than RCC in 5 patients (25.0%) and routine medical checkup in 4 patients (20.0%). First-line imaging modalities for the diagnosis was US in 9 patients (45.0%), DIP in 6 patients (30.0%) and CT in 5 patients (25.0%). Size of the tumor, pathological stage (pT) and grade in these 20 patients were tended to be smaller and lower, respectively, but these results were not significant as compared to those of the control group. Incidence of the remote metastasis, at the time of diagnosis, however, was significantly lesser than that of the control group (p = 0.04).(ABSTRACT TRUNCATED AT 250 WORDS)