Transabdominal ultrasonography plus urine cytology in control of benign bladder tumours.

Transabdominal ultrasonography can detect bladder tumours down to 5 mm in diameter, and in combination with urine cytology it is a potential alternative to cystoscopy for control of bladder tumour patients. This modality was compared with cystoscopy in 260 investigations on patients with previous non-invasive tumours. Of 153 negative ultrasonographies 55 (21%) were false negative, overlooking 15 tumours above 5 mm (including 5 flat papillomatous areas), 30 tumours 5 mm or less and 10 flat dysplastic lesions (diagnostic sensitivity 64%). In 14 of the false negative ultrasonographies urine cytology was abnormal, increasing the combined diagnostic sensitivity to 73%. Most overlooked tumours above 5 mm were in bladder neck, anterior wall and dome. Of 89 positive ultrasonographies 15 were false positive (diagnostic specificity 83%). Two patients developed invasive tumours in the study period. One was detected by ultrasound and urine cytology, the other - a flat muscle invasive tumour - was not. Ultrasonography plus urine cytology is only acceptable for control of patients with very little risk of invasive and few non-invasive recurrences, i.e. patients with previous Ta, grade I or II transitional cell tumours and no recurrences after 1 or 2 control cystoscopies.