Transitional cell tumours of the urinary bladder. The histological grade (WHO) and the clinical stage (UICC).

Correlation of histological grade (WHO) with clinical stage (UICC) of transitional epithelial tumours of the bladder has been evaluated in 130 patients. A moderate statistically highly significant positive correlation was established (Pearson's r 0.37--0.75 and eta correlation ratio coefficient 0.49--0.81 in various subsets of the material). Transurethral biopsies gave on average 0.53 lower histological grade than open operative biopsies of the same tumours. The data show that the information contained in histological grade and clinical stage is parallel and support the idea that histological diagnosis of transitional cell carcinoma is possible also in the absence of histological evidence of invasion.