Clinical, histopathological and flow-cytometric properties of incidental renal cell carcinomas

Medical records of 63 patients operated on for renal cell carcinoma (RCC) b etween 1986 and 1996 in the Karlovac General Hospital were studied retrospe ctively. In 23 (36.5%) patients, the tumor was incidentally detected. The m edian patient age was 62 in the incidental group and 64 years in the sympto matic group (P > 0.05). Ultrasonography was the leading technique for incid ental detection of RCC. The median tumor diameter was 6 cm in the incidenta l group and 9 cm in the symptomatic group (P < 0.001), Incidental carcinoma s had a lower stage (P = 0.022) and a lower nuclear grade (P < 0.001) than the symptomatic ones. The incidental cases were associated with a more favo rable ploidy status (P=0.027) and a lower proliferative activity (P = 0.005 ). The 5-year survival rate was significantly higher in incidental (81.4%) than in symptomatic cases (44.3%) (P = 0.020). Univariate analysis showed t hat tumor stage, ploidy status, and proliferative activity were good progno stic parameters, while patient age, tumor size, and nuclear grade were not. Tumor stage was the only independent prognostic parameter in multivariate analysis. In conclusion, the incidentally detected RCC show more favorable clinical, histopathological, and flow-cytometric characteristics and their prognosis is significantly better than in symptomatic cases.