Bladder tumors: when to do and what to expect from random mucosal biopsies with reference to blood group cell surface antigens.

Routine random biopsies of normal looking bladder mucosa in the evaluation of bladder tumors demonstrated a high occurrence of anomalies ranging from dysplasia to carcinoma in situ (CIS). 75 patients with a urothelial bladder tumor were submitted to 165 endoscopic procedures under anesthesia including transurethral resection of any bladder tumor and random mucosal biopsies in the 4 quadrants of the bladder. The frequency and severity of mucosal anomalies rise with the tumor grade and stage: in stage 0.Ta, the percentage of anomalies rises from 15% in grade-1 lesions to 53% in grade-3 tumors. 80% of the stage A (T1) B and C (T2, T3) tumors are associated with anomalies of the normal looking bladder mucosa characterized by CIS in 50% of the cases. These lesions which may persist in the absence of any visible tumor respond dramatically to endovesical bacillus Calmette-Guérin therapy. Simultaneous determinations of blood group antigens fail to demonstrate a clear correlation between the antigenic status of the tumor and that of random biopsies. These results may help to clarify the indications of random mucosal biopsies which should be reserved to the treatment and surveillance of grade 3-tumors, irrespective of their stage.