[Bladder tumors. Indications for and results of routine biopsies of the macroscopically healthy mucosa (with a study of surface antigens)].

The routine biopsy of macroscopically normal mucosa has demonstrated the frequency of anomalies (hyperplasia, dysplasia or carcinoma in situ) associated with bladder tumours. 75 patients with urothelial bladder cancer were investigated by a total of 163 endoscopic examinations which, apart from resection of the tumour, included biopsies of macroscopically healthy mucosa. The frequency and severity of the lesions increased with the grade and the stage of the tumour: in cases with stage O/Ta lesions, the percentage of anomalies increased from 15% with grade 1 to 53% with grade 3. At stage A (T1), anomalies were present in 8 out of 10 cases and consisted of carcinoma in situ in one half of cases. Similar figures were obtained for stages B/C (T2, T3). Lesions which may persist in the absence of a visible tumour respond dramatically to intravesical BCG chemotherapy. Analysis of the surface antigens did not reveal any clear correlation between the antigenic status of the tumour and that of the non-tumoural mucosa. These results clarify the indications for biopsies in macroscopically healthy mucosa, which should be limited to follow-up endoscopies and treatment of grade 3 tumours.