[Studies on multiple mucosal biopsy in patients with bladder cancer. 1. Evaluation of the results of multiple mucosal biopsy in patients with bladder cancer and in vivo methylene blue staining].

Between March, 1980 and July, 1984, 165 multiple mucosal biopsies were performed in 111 patients with bladder cancer. Of these 165 multiple mucosal biopsies, 87 were performed in new cases and 78 in recurrent cases: 147 were performed under in vivo staining with intravesical methylene blue. Before endoscopic tumor resection, biopsies were taken with a flexible cup biopsy forceps from non-tumorous urothelium lateral to the ureteral orifices, in the midline posteriorly, from both lateral wall and bladder neck, adjacent to the tumor and from the tumor itself. Histological abnormalities in this paper indicate transitional cell carcinoma, microinvasion of carcinoma in situ, carcinoma in situ, dysplasia and hyperplasia. In the total 955 biopsy specimens, transitional cell carcinoma was found in 45 (4.7%), microinvasion of carcinoma in situ in 30 (3.1%), carcinoma in situ in 55 (5.8%), dysplasia in 27 (2.8%), hyperplasia in 141 (1.5%), squamous metaplasia in 4 (0.4%), proliferative cystitis in 58 (6.1%), inflammation in 230 (24.1%) and normal epithelium in 492 (51.5%). The frequency of histological abnormalities in biopsied specimens was 14.8% in new cases, 21.1% in recurrent cases, the difference being statistically significant (P less than 0.01). Transitional cell carcinoma and dysplasia were more common in mucosal biopsies of recurrent cases than those of new cases (P less than 0.001, P less than 0.05). The frequency of histological abnormalities was 11.5% in 836 biopsy specimens from cystoscopically normal-looking mucosa, while 65.5% in 119 biopsy specimens from grossly abnormal mucosa, the difference being statistically significant (P less than 0.001). Of histological abnormalities, transitional cell carcinoma, microinvasion of carcinoma in situ and carcinoma in situ were more common in biopsy specimens from grossly abnormal mucosa than those from normal-looking mucosa (P less than 0.001). The frequency of histological abnormalities in mucosal biopsy was 11.4% in patients who exhibited a single tumor, and 26.7% in those with multiple tumors, the difference being significant (P less than 0.005). Biopsies of mucosa adjacent to a visible tumor were abnormal most frequently (26.9%), while those taken lateral to the ureteral orifices, from the midline posteriorly and from both lateral wall revealed a slightly lower rate of abnormal findings. The frequency of histological abnormalities in mucosal biopsy was 7.7% in patients with G1 tumor, 15.8% in those with G2 tumor and 36.0% in those with G3 tumor. The histological abnormalities increased with the increase in the grade of main tumor; this correlation was statistically significant (P less than 0.001).(ABSTRACT TRUNCATED AT 400 WORDS)