Selective surface staining of bladder tumors by intravesical methylene blue with enhanced endoscopic identification

Abstract

Intravesical instillation of methylene blue resulted in selective surface staining of bladder tumors in vivo without staining the background of normal urothelium. Staining of human bladder tumors in vivo was accomplished by the intravesical instillation of 0.1% methylene blue in 0.9% saline through a foley catheter under 20 cm of hydrostatic pressure up to a maximum volume of 400 ml. After 5 minutes contact time, the methylene blue solution was drained, and the bladder was washed with saline. Thereafter, either endoscopic or open surgery was performed. The transitional cell carcinomas in 45 of 48 patients bound methylene blue to the surfaces of the tumors but not to normal urothelium. Higher grade tumors usually bound the dye more extensively than lower grades. The three patients, whose tumors did not bind methylene blue, had received previous chemotherapy, which might account for their being falsely negative. Carcinoma in situ and dysplasia did stain blue. Areas of hyperplasia and cystitis, however, did not bind methylene blue. In vivo intravesical staining with methylene blue has been a simple and safe procedure which has enhanced the endoscopic localization for biopsy and fulguration/resection of transitional cell carcinomas.