[Incidental versus clinical renal adenocarcinoma: comparative study (1970-1994)].

A revision has been made of 286 renal adenocarcinoma treated in the Urology service at the Hospital marqués de Valdecilla, Santander, during the period from January 1970 through December 1994, dividing the study in two groups based on diagnosis being incidental or clinically suspected, and comparing the following parameters: 5-year intervals incidence, age, gender, intrarenal location, tumoral diameter, histology, nuclear grade, tumour stage and survival. The objective was to analyze the possible differences between renal cell neoplasias diagnosed based on clinical behaviour and those diagnosed incidentally over a 25 year period. Of the 286 renal adenocarcinomas, 217 (77.5%) were symptomatic at diagnosis, 63 (22.5% were found accidentally, while presentation in 6 cases is unknown. The percentage of incidental diagnosis increases gradually from 0% during the 1970-75 period to 44.2% from 1990 to 1994. No significant differences were found between incidental and clinical cases with regard to gender, age at presentation, affected side or intrarenal location of the tumours. The tumoral diameter of incidental cases was 6.74 +/- 3.31 cm, and 8.53 +/- 3.66 in the clinical ones, the difference being significant (p < 0.001). Nuclear grade is lower in incidental cases than in clinical ones, with a significant difference (p < 0.01). Asymptomatic tumours occur with higher proportion at low Robson stages, 60.3% stage I vs. 30.5% of symptomatic cases (p < 0.001). A comparison of survival shows the existence of significant differences (p < 0.001) between incidentalomas and clinical adenocarcinomas, the significance in this differences fading when both groups are compared based on the stage. Relative to suspected cases, incidental tumours present less size, lower nuclear grade, lower stage and better survival, all these differences being highly significant. No significant differences are seen in survival between incidentalomas and symptomatic ones when compared by stage at tumour presentation.