[Survivals of incidental renal cell carcinoma]

Between January 1987 and July 1988, 151 cases of renal cell carcinoma were nephrectomized at out institutions. Among them 41 cases (27.2%) were diagnosed incidentally. The ratio of incidental carcinoma has been increasing steadily in the past decade. Thirty-four of these cases (82.9%) were detected by ultrasound, 4 by computerized tomography, and three by excretory urography. Twenty-eight of these cases were found serendipitously during examination for other diseases, while others had no symptoms at all. Only 8 of these cases (19.5%) showed microscopic hematuria. The stage and the grade of these incidental carcinoma were significantly lower than those of symptomatic carcinoma (p less than 0.001). The survival rate of the former was better than that of the latter (p less than 0.01), especially in patients with pT1-2b tumors (p less than 0.05) or with tumors smaller than 10 cm in diameter (p less than 0.05).