Staging of bladder carcinoma by computer tomography-guided transmural core biopsy.

In an attempt to improve staging of bladder cancer, computed tomography-guided transmural core biopsy was performed in 17 patients. In the first four patients a 0.9 mm cutting needle was used. This small needle yielded easily fragmented cores and consequently the remaining biopsies were taken with a 1.2 mm needle with an improved result. In all but one case sufficient histological material to allow a diagnosis was obtained by the core biopsy technique. Transmural tumor infiltration, as verified in corresponding cystectomy specimens, could be identified more often with the core biopsy than in biopsies obtained by transurethral resection. False negative diagnosis occurred when the tumor was not clearly visible on the computed tomography scan. No short-term side effects of clinical importance were found with the procedure.