A constant rejection of cells from normal urothelium and malignant cells occurs in the bladder. These rejected cells can be isolated from a regular urine sample and assessed and classified as normal or malignant.
Urine cytology is most reliable for detecting tumors of higher grade (WHO grade 2 and 3) and Tis. A tumor of WHO malignancy grade 1 will give a positive cytology to a lesser degree. Due to a low cell count, degenerative -, irritative - (for example calculous disease or cystoscopy urine) and therapy-induced (BCG and radiation therapy) changes, the cytological interpretation of the specimen may be problematic.
- Hematuria not explained at cystoscopy and urography
- Ambiguous finding at cystoscopy
- Negative cystoscopy in patient with suspect UTI-symptoms
- Negative cystoscopy and possible tumor in upper urinary tract from urography/ultrasound
- Follow-up of certain patients (for exmple Tis)